refactor(android): split session JNI into modules, HUD-gated stats, AAudio open retry

- native: the 756-line session.rs becomes session/{mod,connect,input,planes}.rs
  around a SessionHandle (connect lifecycle + trust, input plane shims, plane
  start/stop + stats drain).
- Decode-stats sampling is HUD-gated (nativeSetVideoStatsEnabled): with the
  overlay hidden the decode thread skips the per-AU clock read + lock; enabling
  resets the measurement window.
- audio: the AAudio open path is a per-sharing-mode try_open closure — the
  realtime callback state (ring, prime, free-list) is rebuilt per attempt, so a
  failed exclusive-mode try can't leak state into the shared-mode retry.
- Kotlin: ConnectScreen/StreamScreen slimmed by extracting ConnectDialogs,
  StatsOverlay and TouchInput.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

clients/android/README.md

@@ -9,7 +9,7 @@ couch (D-pad / gamepad focus navigation).
 
 - **Hardware decode** — NDK `AMediaCodec` HEVC → `SurfaceView`, including **HDR10** (Main10 /
   BT.2020 PQ), with low-latency tuning and a live stats HUD.
-- **Audio both ways** — Opus + Oboe playback with a jitter ring, plus mic uplink to the host.
+- **Audio both ways** — Opus + AAudio playback with a jitter ring, plus mic uplink to the host.
 - **Controller support** — buttons + axes with rumble and HID feedback (lightbar / adaptive
   triggers); D-pad / gamepad focus navigation for TV and phone.
 - **Find hosts automatically** — native mDNS discovery; first connect does a one-time **SPAKE2 PIN
@@ -33,18 +33,19 @@ machine, trust logic) instead of re-porting it into Kotlin.
 
 | Side | Owns |
 |------|------|
-| **Rust** (`native/` → `libpunktfunk_android.so`) | the JNI seam, `NativeClient` (QUIC control + UDP data plane), AnnexB → `AMediaCodec` decode (incl. HDR10), Opus + Oboe audio + mic, controller feedback, latency math, trust/pairing, `mdns-sd` discovery |
+| **Rust** (`native/` → `libpunktfunk_android.so`) | the JNI seam, `NativeClient` (QUIC control + UDP data plane), AnnexB → `AMediaCodec` decode (incl. HDR10), Opus + AAudio audio + mic, controller feedback, latency math, trust/pairing, `mdns-sd` discovery |
 | **Kotlin** (`app/`, `kit/`) | Compose UI, `SurfaceView` lifecycle, input capture, the Wi-Fi `MulticastLock` + permission UX, Keystore identity |
 
 The single seam is `io.unom.punktfunk.kit.NativeBridge` ⇄ `Java_io_unom_punktfunk_kit_NativeBridge_*`.
 
 ```
 native/           Rust cdylib (workspace member) — links punktfunk-core directly
-  src/lib.rs        JNI seam (connect/pair, input, plane getters, versions)
+  src/lib.rs        crate doc · JNI_OnLoad · version probes
-  src/session.rs    session lifecycle + plane pumps
+  src/session/      session lifecycle: connect/pair + trust, plane start/stop, input shims
   src/decode.rs     AnnexB → AMediaCodec HEVC hardware decode → SurfaceView (incl. HDR10)
-  src/audio.rs · src/mic.rs   Opus + Oboe playback / mic uplink
+  src/audio.rs · src/mic.rs   Opus + AAudio playback / mic uplink
   src/feedback.rs · src/stats.rs   rumble + HID feedback; live video stats
+  src/discovery.rs  native mdns-sd browse of the host's _punktfunk._udp advert
 app/              :app — Compose UI: Connect / Settings / Stream (phone + TV)
 kit/              :kit — NativeBridge · native mDNS discovery · Gamepad · Keymap · Keystore identity
 ```

clients/android/app/src/main/kotlin/io/unom/punktfunk/ConnectDialogs.kt

@@ -0,0 +1,355 @@
+package io.unom.punktfunk
+
+import android.os.Build
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Button
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.unit.dp
+import io.unom.punktfunk.kit.NativeBridge
+import io.unom.punktfunk.kit.security.ClientIdentity
+import io.unom.punktfunk.kit.security.KnownHost
+import io.unom.punktfunk.models.PendingTrust
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+
+/**
+ * The "Add host" bottom sheet: optional name + address + port, then connect at [modeLabel]. Field
+ * state stays hoisted in ConnectScreen so a dismissed sheet keeps its half-typed values.
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+internal fun AddHostSheet(
+    hostName: String,
+    onHostNameChange: (String) -> Unit,
+    host: String,
+    onHostChange: (String) -> Unit,
+    port: String,
+    onPortChange: (String) -> Unit,
+    connecting: Boolean,
+    modeLabel: String,
+    onDismiss: () -> Unit,
+    onConnect: (host: String, port: Int, name: String) -> Unit,
+) {
+    val scope = rememberCoroutineScope()
+    val sheetState = rememberModalBottomSheetState()
+    ModalBottomSheet(
+        onDismissRequest = onDismiss,
+        sheetState = sheetState,
+    ) {
+        Column(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 24.dp)
+                .padding(bottom = 32.dp),
+        ) {
+            Text("Add a host", style = MaterialTheme.typography.titleLarge)
+            Spacer(Modifier.height(4.dp))
+            Text(
+                "Enter its address. You'll pair with the host's PIN on first connect.",
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            Spacer(Modifier.height(20.dp))
+            OutlinedTextField(
+                value = hostName,
+                onValueChange = onHostNameChange,
+                label = { Text("Name (optional)") },
+                placeholder = { Text("e.g. Living Room") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth(),
+            )
+            Spacer(Modifier.height(16.dp))
+            OutlinedTextField(
+                value = host,
+                onValueChange = onHostChange,
+                label = { Text("Host") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth(),
+            )
+            Spacer(Modifier.height(16.dp))
+            OutlinedTextField(
+                value = port,
+                onValueChange = { v -> onPortChange(v.filter { it.isDigit() }.take(5)) },
+                label = { Text("Port") },
+                singleLine = true,
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+                modifier = Modifier.fillMaxWidth(),
+            )
+            Spacer(Modifier.height(20.dp))
+            Button(
+                enabled = !connecting && host.isNotBlank() && port.isNotBlank(),
+                onClick = {
+                    val h = host.trim()
+                    val p = port.toIntOrNull() ?: 9777
+                    val n = hostName
+                    scope.launch { sheetState.hide() }.invokeOnCompletion {
+                        onDismiss()
+                        onConnect(h, p, n)
+                    }
+                },
+                modifier = Modifier.fillMaxWidth(),
+            ) { Text("Connect  ($modeLabel)") }
+        }
+    }
+}
+
+/** First connection to a host that advertised pair=optional: offer TOFU, but pitch PIN pairing. */
+@Composable
+internal fun TrustNewHostDialog(
+    pt: PendingTrust,
+    onTrust: () -> Unit,
+    onPairInstead: () -> Unit,
+    onDismiss: () -> Unit,
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Trust this host?") },
+        text = {
+            Column {
+                Text("First connection to ${pt.host}:${pt.port}.")
+                pt.advertisedFp?.let { Text("Fingerprint ${it.take(16)}…") }
+                Text(
+                    "This host allows trust-on-first-use, but that can't tell an impostor " +
+                        "from the real host. Pairing with a PIN is stronger — it proves both sides.",
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = onTrust) { Text("Trust (TOFU)") }
+        },
+        dismissButton = {
+            Row {
+                TextButton(onClick = onPairInstead) { Text("Pair with PIN…") }
+                TextButton(onClick = onDismiss) { Text("Cancel") }
+            }
+        },
+    )
+}
+
+/** The pinned fingerprint no longer matches — force re-pairing (never a silent re-trust). */
+@Composable
+internal fun FingerprintChangedDialog(
+    pt: PendingTrust,
+    onRepair: () -> Unit,
+    onDismiss: () -> Unit,
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Host identity changed") },
+        text = {
+            Text(
+                "The pinned fingerprint for ${pt.host} no longer matches what it now " +
+                    "advertises. This can mean a host reinstall — or an impostor. Re-pair " +
+                    "with the host's PIN to continue.",
+            )
+        },
+        confirmButton = {
+            TextButton(onClick = onRepair) { Text("Re-pair") }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text("Cancel") }
+        },
+    )
+}
+
+/**
+ * A fresh pair=required (or manual/unknown-policy) host: offer the two ways in. "Request access" is
+ * the no-PIN path — connect and wait for the operator to click Approve in the host's console;
+ * "Use a PIN…" switches to the SPAKE2 ceremony.
+ */
+@Composable
+internal fun RequestAccessDialog(
+    pt: PendingTrust,
+    onRequestAccess: () -> Unit,
+    onUsePin: () -> Unit,
+    onDismiss: () -> Unit,
+) {
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Pairing required") },
+        text = {
+            Column {
+                Text("${pt.host}:${pt.port} requires pairing before it will stream.")
+                Text(
+                    "Request access and approve this device in the host's console (or web " +
+                        "UI) — no PIN needed. Or pair with the 4-digit PIN the host displays.",
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = onRequestAccess) { Text("Request access") }
+        },
+        dismissButton = {
+            Row {
+                TextButton(onClick = onUsePin) { Text("Use a PIN…") }
+                TextButton(onClick = onDismiss) { Text("Cancel") }
+            }
+        },
+    )
+}
+
+/**
+ * The SPAKE2 PIN ceremony dialog. Runs [NativeBridge.nativePair] off the UI thread itself (the
+ * pin/name/error state is dialog-local); on success hands the host's verified fingerprint to
+ * [onPaired], which saves + connects. Dismissal is blocked while a pair attempt is in flight.
+ */
+@Composable
+internal fun PairPinDialog(
+    pt: PendingTrust,
+    identity: ClientIdentity?,
+    onPaired: (fpHex: String) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    val scope = rememberCoroutineScope()
+    var pin by remember(pt) { mutableStateOf("") }
+    var name by remember(pt) { mutableStateOf(Build.MODEL ?: "Android") }
+    var pairing by remember(pt) { mutableStateOf(false) }
+    var err by remember(pt) { mutableStateOf<String?>(null) }
+    AlertDialog(
+        onDismissRequest = { if (!pairing) onDismiss() },
+        title = { Text("Pair with PIN") },
+        text = {
+            Column {
+                Text("Enter the 4-digit PIN shown on the host.")
+                OutlinedTextField(
+                    value = pin,
+                    onValueChange = { v -> pin = v.filter { it.isDigit() }.take(4) },
+                    label = { Text("PIN") },
+                    singleLine = true,
+                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+                )
+                OutlinedTextField(
+                    value = name,
+                    onValueChange = { name = it },
+                    label = { Text("This device") },
+                    singleLine = true,
+                )
+                err?.let { Text(it, color = MaterialTheme.colorScheme.error) }
+            }
+        },
+        confirmButton = {
+            TextButton(
+                enabled = !pairing && pin.length == 4 && identity != null,
+                onClick = {
+                    val id = identity
+                    if (id != null) {
+                        pairing = true
+                        err = null
+                        scope.launch {
+                            val fp = withContext(Dispatchers.IO) {
+                                NativeBridge.nativePair(
+                                    pt.host, pt.port, id.certPem, id.privateKeyPem, pin, name,
+                                )
+                            }
+                            pairing = false
+                            if (fp.isNotEmpty()) {
+                                onPaired(fp) // verified host fp — caller saves + connects
+                            } else {
+                                err = "Pairing failed — wrong PIN, or the host isn't armed."
+                            }
+                        }
+                    }
+                },
+            ) { Text(if (pairing) "Pairing…" else "Pair") }
+        },
+        dismissButton = {
+            TextButton(enabled = !pairing, onClick = onDismiss) { Text("Cancel") }
+        },
+    )
+}
+
+/**
+ * The no-PIN "request access" wait: the connect is parked on the host until the operator approves
+ * this device. Cancel returns the UI immediately — the caller trips the per-attempt flag so a late
+ * approval is torn down silently (see ConnectScreen.requestAccess) and resumes discovery.
+ */
+@Composable
+internal fun AwaitingApprovalDialog(hostLabel: String, onCancel: () -> Unit) {
+    AlertDialog(
+        onDismissRequest = onCancel,
+        title = { Text("Waiting for approval") },
+        text = {
+            val deviceName = Build.MODEL ?: "this device"
+            Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.spacedBy(12.dp),
+                ) {
+                    CircularProgressIndicator(modifier = Modifier.size(20.dp), strokeWidth = 2.dp)
+                    Text("Approve this device on $hostLabel.")
+                }
+                Text(
+                    "Open the host's console (or web UI) and approve “$deviceName”. It connects " +
+                        "automatically once you approve — no PIN needed.",
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        },
+        confirmButton = {},
+        dismissButton = {
+            TextButton(onClick = onCancel) { Text("Cancel") }
+        },
+    )
+}
+
+/**
+ * Rename a saved host's label (discovered hosts are named by mDNS; this is how you give one a
+ * friendly name like "Living Room" after pairing). Keyed by the host so reopening resets the field.
+ */
+@Composable
+internal fun RenameHostDialog(
+    target: KnownHost,
+    onRename: (String) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    var newName by remember(target) { mutableStateOf(target.name) }
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Rename host") },
+        text = {
+            OutlinedTextField(
+                value = newName,
+                onValueChange = { newName = it },
+                label = { Text("Name") },
+                placeholder = { Text(target.address) },
+                singleLine = true,
+            )
+        },
+        confirmButton = {
+            TextButton(
+                enabled = newName.isNotBlank(),
+                onClick = { onRename(newName.trim()) },
+            ) { Text("Save") }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) { Text("Cancel") }
+        },
+    )
+}

clients/android/app/src/main/kotlin/io/unom/punktfunk/ConnectScreen.kt

@@ -6,11 +6,6 @@ import android.content.pm.PackageManager
 import android.os.Build
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
-import androidx.compose.animation.AnimatedVisibility
-import androidx.compose.animation.fadeIn
-import androidx.compose.animation.fadeOut
-import androidx.compose.animation.scaleIn
-import androidx.compose.animation.scaleOut
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -27,24 +22,14 @@ import androidx.compose.foundation.lazy.grid.GridCells
 import androidx.compose.foundation.lazy.grid.GridItemSpan
 import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
 import androidx.compose.foundation.lazy.grid.items
-import androidx.compose.foundation.rememberScrollState
-import androidx.compose.foundation.text.KeyboardOptions
-import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Add
-import androidx.compose.material3.AlertDialog
-import androidx.compose.material3.Button
 import androidx.compose.material3.CircularProgressIndicator
-import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.ExtendedFloatingActionButton
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.ModalBottomSheet
-import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
-import androidx.compose.material3.TextButton
-import androidx.compose.material3.rememberModalBottomSheetState
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
@@ -56,7 +41,6 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.core.content.ContextCompat
@@ -99,7 +83,6 @@ private class RequestAccessState(val target: PendingTrust) {
     val cancelled = AtomicBoolean(false)
 }
 
-@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun ConnectScreen(settings: Settings, onConnected: (Long) -> Unit) {
     val scope = rememberCoroutineScope()
@@ -162,6 +145,26 @@ fun ConnectScreen(settings: Settings, onConnected: (Long) -> Unit) {
     // it survives a DHCP address change; else by address:port). Mirrors the Apple client.
     val discoveredUnsaved = discovered.filter { dh -> savedHosts.none { it.matches(dh) } }
 
+    // The one place the full nativeConnect is issued (shared by the normal connect and the
+    // request-access path), including the HDR/gamepad derivation both need.
+    suspend fun connectNative(id: ClientIdentity, targetHost: String, targetPort: Int, pinHex: String, timeoutMs: Int): Long {
+        // Advertise HDR only when the user enabled it AND this device's display can present it
+        // (else the host sends a proper SDR stream rather than PQ the panel would mis-tone-map).
+        val hdrEnabled = settings.hdrEnabled && displaySupportsHdr(context)
+        // "Automatic" resolves to a concrete pad type from the connected controller's VID/PID
+        // (Android exposes no controller-type enum) — parity with the Linux/Apple clients. An
+        // explicit choice is passed through unchanged.
+        val gamepadPref = Gamepad.resolvePref(settings.gamepad)
+        return withContext(Dispatchers.IO) {
+            NativeBridge.nativeConnect(
+                targetHost, targetPort, w, h, hz,
+                id.certPem, id.privateKeyPem, pinHex,
+                settings.bitrateKbps, settings.compositor, gamepadPref,
+                hdrEnabled, settings.audioChannels, settings.preferredCodec(), timeoutMs,
+            )
+        }
+    }
+
     // Issue the actual connect with identity + (optional) pin. On a TOFU connect (pinHex null),
     // pin the fingerprint the host presented (as an unpaired known host) so the next connect goes
     // straight through and it appears in the saved-hosts list.
@@ -175,22 +178,7 @@ fun ConnectScreen(settings: Settings, onConnected: (Long) -> Unit) {
         status = "Connecting to $targetHost:$targetPort…"
         discovery.stop() // free the Wi-Fi radio before the stream session
         scope.launch {
-            // Advertise HDR only when the user enabled it AND this device's display can present it
+            val handle = connectNative(id, targetHost, targetPort, pinHex ?: "", CONNECT_TIMEOUT_MS)
-            // (else the host sends a proper SDR stream rather than PQ the panel would mis-tone-map).
-            val hdrEnabled = settings.hdrEnabled && displaySupportsHdr(context)
-            // "Automatic" resolves to a concrete pad type from the connected controller's VID/PID
-            // (Android exposes no controller-type enum) — parity with the Linux/Apple clients. An
-            // explicit choice is passed through unchanged.
-            val gamepadPref = Gamepad.resolvePref(settings.gamepad)
-            val handle = withContext(Dispatchers.IO) {
-                NativeBridge.nativeConnect(
-                    targetHost, targetPort, w, h, hz,
-                    id.certPem, id.privateKeyPem, pinHex ?: "",
-                    settings.bitrateKbps, settings.compositor, gamepadPref,
-                    hdrEnabled, settings.audioChannels, settings.preferredCodec(),
-                    CONNECT_TIMEOUT_MS,
-                )
-            }
             connecting = false
             if (handle != 0L) {
                 if (pinHex == null) { // TOFU: pin what we observed (unpaired)
@@ -225,19 +213,10 @@ fun ConnectScreen(settings: Settings, onConnected: (Long) -> Unit) {
         status = null
         discovery.stop() // free the Wi-Fi radio before the (parked) stream session
         scope.launch {
-            val hdrEnabled = settings.hdrEnabled && displaySupportsHdr(context)
-            val gamepadPref = Gamepad.resolvePref(settings.gamepad)
             // Pin the advertised fingerprint for a discovered host (defence against an impostor while
             // we wait); a manually-typed host has none, so trust-on-first-use.
             val pinHex = target.advertisedFp ?: ""
-            val handle = withContext(Dispatchers.IO) {
+            val handle = connectNative(id, target.host, target.port, pinHex, REQUEST_ACCESS_TIMEOUT_MS)
-                NativeBridge.nativeConnect(
-                    target.host, target.port, w, h, hz,
-                    id.certPem, id.privateKeyPem, pinHex,
-                    settings.bitrateKbps, settings.compositor, gamepadPref,
-                    hdrEnabled, settings.audioChannels, REQUEST_ACCESS_TIMEOUT_MS,
-                )
-            }
             // Cancelled while we were parked: tear the (possibly just-approved) session down and
             // don't touch UI a fresh action may now own.
             if (req.cancelled.get()) {
@@ -296,7 +275,6 @@ fun ConnectScreen(settings: Settings, onConnected: (Long) -> Unit) {
         }
     }
 
-    val sheetState = rememberModalBottomSheetState()
     var showManualSheet by remember { mutableStateOf(false) }
 
     Box(Modifier.fillMaxSize()) {
@@ -428,291 +406,87 @@ fun ConnectScreen(settings: Settings, onConnected: (Long) -> Unit) {
             }
         }
 
-        AnimatedVisibility(
-            visible = true, // Static for now, could be based on scroll if needed
-            enter = scaleIn() + fadeIn(),
-            exit = scaleOut() + fadeOut(),
-            modifier = Modifier
-                .align(Alignment.BottomEnd)
-                .padding(20.dp)
-        ) {
         ExtendedFloatingActionButton(
             onClick = { showManualSheet = true },
             icon = { Icon(Icons.Filled.Add, contentDescription = null) },
             text = { Text("Add host") },
             expanded = !connecting,
+            modifier = Modifier
+                .align(Alignment.BottomEnd)
+                .padding(20.dp),
         )
     }
-    }
 
     if (showManualSheet) {
-        ModalBottomSheet(
+        AddHostSheet(
-            onDismissRequest = { showManualSheet = false },
+            hostName = hostName,
-            sheetState = sheetState,
+            onHostNameChange = { hostName = it },
-        ) {
+            host = host,
-            Column(
+            onHostChange = { host = it },
-                modifier = Modifier
+            port = port,
-                    .fillMaxWidth()
+            onPortChange = { port = it },
-                    .padding(horizontal = 24.dp)
+            connecting = connecting,
-                    .padding(bottom = 32.dp),
+            modeLabel = "$w×$h@$hz",
-            ) {
+            onDismiss = { showManualSheet = false },
-                Text("Add a host", style = MaterialTheme.typography.titleLarge)
+            onConnect = { h2, p, n -> connect(h2, p, manualName = n) },
-                Spacer(Modifier.height(4.dp))
-                Text(
-                    "Enter its address. You'll pair with the host's PIN on first connect.",
-                    style = MaterialTheme.typography.bodyMedium,
-                    color = MaterialTheme.colorScheme.onSurfaceVariant,
         )
-                Spacer(Modifier.height(20.dp))
-                OutlinedTextField(
-                    value = hostName,
-                    onValueChange = { hostName = it },
-                    label = { Text("Name (optional)") },
-                    placeholder = { Text("e.g. Living Room") },
-                    singleLine = true,
-                    modifier = Modifier.fillMaxWidth(),
-                )
-                Spacer(Modifier.height(16.dp))
-                OutlinedTextField(
-                    value = host,
-                    onValueChange = { host = it },
-                    label = { Text("Host") },
-                    singleLine = true,
-                    modifier = Modifier.fillMaxWidth(),
-                )
-                Spacer(Modifier.height(16.dp))
-                OutlinedTextField(
-                    value = port,
-                    onValueChange = { v -> port = v.filter { it.isDigit() }.take(5) },
-                    label = { Text("Port") },
-                    singleLine = true,
-                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
-                    modifier = Modifier.fillMaxWidth(),
-                )
-                Spacer(Modifier.height(20.dp))
-                Button(
-                    enabled = !connecting && host.isNotBlank() && port.isNotBlank(),
-                    onClick = {
-                        val h = host.trim()
-                        val p = port.toIntOrNull() ?: 9777
-                        val n = hostName
-                        scope.launch { sheetState.hide() }.invokeOnCompletion {
-                            showManualSheet = false
-                            connect(h, p, manualName = n)
-                        }
-                    },
-                    modifier = Modifier.fillMaxWidth(),
-                ) { Text("Connect  ($w×$h@$hz)") }
-            }
-        }
     }
 
     pendingTrust?.let { pt ->
         when (pt.kind) {
-            PendingTrust.Kind.TRUST_NEW -> AlertDialog(
+            PendingTrust.Kind.TRUST_NEW -> TrustNewHostDialog(
-                onDismissRequest = { pendingTrust = null },
+                pt = pt,
-                title = { Text("Trust this host?") },
+                onTrust = { pendingTrust = null; doConnect(pt.host, pt.port, pt.name, null) },
-                text = {
+                onPairInstead = { pendingTrust = pt.copy(kind = PendingTrust.Kind.PAIR) },
-                    Column {
+                onDismiss = { pendingTrust = null },
-                        Text("First connection to ${pt.host}:${pt.port}.")
-                        pt.advertisedFp?.let { Text("Fingerprint ${it.take(16)}…") }
-                        Text(
-                            "This host allows trust-on-first-use, but that can't tell an impostor " +
-                                "from the real host. Pairing with a PIN is stronger — it proves both sides.",
             )
-                    }
+            PendingTrust.Kind.FP_CHANGED -> FingerprintChangedDialog(
-                },
+                pt = pt,
-                confirmButton = {
+                onRepair = { pendingTrust = pt.copy(kind = PendingTrust.Kind.PAIR) },
-                    TextButton({ pendingTrust = null; doConnect(pt.host, pt.port, pt.name, null) }) {
+                onDismiss = { pendingTrust = null },
-                        Text("Trust (TOFU)")
-                    }
-                },
-                dismissButton = {
-                    Row {
-                        TextButton({ pendingTrust = pt.copy(kind = PendingTrust.Kind.PAIR) }) {
-                            Text("Pair with PIN…")
-                        }
-                        TextButton({ pendingTrust = null }) { Text("Cancel") }
-                    }
-                },
             )
-            PendingTrust.Kind.FP_CHANGED -> AlertDialog(
+            PendingTrust.Kind.REQUEST_ACCESS -> RequestAccessDialog(
-                onDismissRequest = { pendingTrust = null },
+                pt = pt,
-                title = { Text("Host identity changed") },
+                onRequestAccess = { pendingTrust = null; requestAccess(pt) },
-                text = {
+                onUsePin = { pendingTrust = pt.copy(kind = PendingTrust.Kind.PAIR) },
-                    Text(
+                onDismiss = { pendingTrust = null },
-                        "The pinned fingerprint for ${pt.host} no longer matches what it now " +
-                            "advertises. This can mean a host reinstall — or an impostor. Re-pair " +
-                            "with the host's PIN to continue.",
-                    )
-                },
-                confirmButton = {
-                    TextButton({ pendingTrust = pt.copy(kind = PendingTrust.Kind.PAIR) }) { Text("Re-pair") }
-                },
-                dismissButton = {
-                    TextButton({ pendingTrust = null }) { Text("Cancel") }
-                },
-            )
-            // A fresh pair=required (or manual/unknown-policy) host: offer the two ways in. "Request
-            // access" is the no-PIN path — connect and wait for the operator to click Approve in the
-            // host's console; "Use a PIN…" switches to the SPAKE2 ceremony.
-            PendingTrust.Kind.REQUEST_ACCESS -> AlertDialog(
-                onDismissRequest = { pendingTrust = null },
-                title = { Text("Pairing required") },
-                text = {
-                    Column {
-                        Text("${pt.host}:${pt.port} requires pairing before it will stream.")
-                        Text(
-                            "Request access and approve this device in the host's console (or web " +
-                                "UI) — no PIN needed. Or pair with the 4-digit PIN the host displays.",
-                        )
-                    }
-                },
-                confirmButton = {
-                    TextButton({ pendingTrust = null; requestAccess(pt) }) { Text("Request access") }
-                },
-                dismissButton = {
-                    Row {
-                        TextButton({ pendingTrust = pt.copy(kind = PendingTrust.Kind.PAIR) }) {
-                            Text("Use a PIN…")
-                        }
-                        TextButton({ pendingTrust = null }) { Text("Cancel") }
-                    }
-                },
-            )
-            PendingTrust.Kind.PAIR -> {
-                var pin by remember(pt) { mutableStateOf("") }
-                var name by remember(pt) { mutableStateOf(Build.MODEL ?: "Android") }
-                var pairing by remember(pt) { mutableStateOf(false) }
-                var err by remember(pt) { mutableStateOf<String?>(null) }
-                AlertDialog(
-                    onDismissRequest = { if (!pairing) pendingTrust = null },
-                    title = { Text("Pair with PIN") },
-                    text = {
-                        Column {
-                            Text("Enter the 4-digit PIN shown on the host.")
-                            OutlinedTextField(
-                                value = pin,
-                                onValueChange = { v -> pin = v.filter { it.isDigit() }.take(4) },
-                                label = { Text("PIN") },
-                                singleLine = true,
-                                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
-                            )
-                            OutlinedTextField(
-                                value = name,
-                                onValueChange = { name = it },
-                                label = { Text("This device") },
-                                singleLine = true,
-                            )
-                            err?.let { Text(it, color = MaterialTheme.colorScheme.error) }
-                        }
-                    },
-                    confirmButton = {
-                        TextButton(
-                            enabled = !pairing && pin.length == 4 && identity != null,
-                            onClick = {
-                                val id = identity
-                                if (id != null) {
-                                    pairing = true
-                                    err = null
-                                    scope.launch {
-                                        val fp = withContext(Dispatchers.IO) {
-                                            NativeBridge.nativePair(
-                                                pt.host, pt.port, id.certPem, id.privateKeyPem, pin, name,
-                                            )
-                                        }
-                                        pairing = false
-                                        if (fp.isNotEmpty()) {
-                                            // Verified host fp — save as a paired known host.
-                                            knownHostStore.save(
-                                                KnownHost(pt.host, pt.port, pt.name, fp, paired = true),
             )
+            PendingTrust.Kind.PAIR -> PairPinDialog(
+                pt = pt,
+                identity = identity,
+                onPaired = { fp ->
+                    // Verified host fp — save as a paired known host, then connect pinned.
+                    knownHostStore.save(KnownHost(pt.host, pt.port, pt.name, fp, paired = true))
                     savedHosts = knownHostStore.all()
                     pendingTrust = null
                     doConnect(pt.host, pt.port, pt.name, fp)
-                                        } else {
-                                            err = "Pairing failed — wrong PIN, or the host isn't armed."
-                                        }
-                                    }
-                                }
-                            },
-                        ) { Text(if (pairing) "Pairing…" else "Pair") }
-                    },
-                    dismissButton = {
-                        TextButton(enabled = !pairing, onClick = { pendingTrust = null }) { Text("Cancel") }
                 },
+                onDismiss = { pendingTrust = null },
             )
         }
     }
-    }
 
-    // The no-PIN "request access" wait: the connect is parked on the host until the operator
-    // approves this device. Cancel returns the UI immediately — it trips the per-attempt flag so a
-    // late approval is torn down silently (see requestAccess) and resumes discovery.
     awaiting?.let { req ->
-        fun cancel() {
+        AwaitingApprovalDialog(
+            hostLabel = req.target.name,
+            onCancel = {
                 req.cancelled.set(true)
                 awaiting = null
                 connecting = false
                 discovery.start() // the request may still be pending on the host; keep scanning
-        }
-        AlertDialog(
-            onDismissRequest = { cancel() },
-            title = { Text("Waiting for approval") },
-            text = {
-                val deviceName = Build.MODEL ?: "this device"
-                Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
-                    Row(
-                        verticalAlignment = Alignment.CenterVertically,
-                        horizontalArrangement = Arrangement.spacedBy(12.dp),
-                    ) {
-                        CircularProgressIndicator(modifier = Modifier.size(20.dp), strokeWidth = 2.dp)
-                        Text("Approve this device on ${req.target.name}.")
-                    }
-                    Text(
-                        "Open the host's console (or web UI) and approve “$deviceName”. It connects " +
-                            "automatically once you approve — no PIN needed.",
-                        style = MaterialTheme.typography.bodyMedium,
-                        color = MaterialTheme.colorScheme.onSurfaceVariant,
-                    )
-                }
-            },
-            confirmButton = {},
-            dismissButton = {
-                TextButton(onClick = { cancel() }) { Text("Cancel") }
             },
         )
     }
 
-    // Rename a saved host's label (discovered hosts are named by mDNS; this is how you give one a
-    // friendly name like "Living Room" after pairing). Keyed by the host so reopening resets the field.
     renameTarget?.let { kh ->
-        var newName by remember(kh) { mutableStateOf(kh.name) }
+        RenameHostDialog(
-        AlertDialog(
+            target = kh,
-            onDismissRequest = { renameTarget = null },
+            onRename = { newName ->
-            title = { Text("Rename host") },
+                knownHostStore.rename(kh.address, kh.port, newName)
-            text = {
-                OutlinedTextField(
-                    value = newName,
-                    onValueChange = { newName = it },
-                    label = { Text("Name") },
-                    placeholder = { Text(kh.address) },
-                    singleLine = true,
-                )
-            },
-            confirmButton = {
-                TextButton(
-                    enabled = newName.isNotBlank(),
-                    onClick = {
-                        knownHostStore.rename(kh.address, kh.port, newName.trim())
                 savedHosts = knownHostStore.all()
                 renameTarget = null
             },
-                ) { Text("Save") }
+            onDismiss = { renameTarget = null },
-            },
-            dismissButton = {
-                TextButton(onClick = { renameTarget = null }) { Text("Cancel") }
-            },
         )
     }
 }

clients/android/app/src/main/kotlin/io/unom/punktfunk/StatsOverlay.kt

@@ -0,0 +1,98 @@
+package io.unom.punktfunk
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import io.unom.punktfunk.kit.NativeBridge
+import kotlin.math.roundToInt
+
+/**
+ * The live stats overlay — mirrors the Apple client's HUD. Reads the 14-double layout from
+ * [NativeBridge.nativeVideoStats]:
+ * `[fps, mbps, latP50Ms, latP95Ms, latValid, skew, w, h, hz, dropped, bitDepth, colorPrimaries,
+ * colorTransfer, chromaFormatIdc]`. The trailing four (present on a current native lib) describe the
+ * negotiated video feed and render as a codec/depth/colour/chroma line; older layouts just omit it.
+ */
+@Composable
+internal fun StatsOverlay(s: DoubleArray, modifier: Modifier = Modifier) {
+    if (s.size < 10) return
+    val w = s[6].toInt()
+    val h = s[7].toInt()
+    val hz = s[8].toInt()
+    val latValid = s[4] != 0.0
+    val skew = s[5] != 0.0
+    val dropped = s[9].toLong()
+    Column(
+        modifier = modifier
+            .background(Color.Black.copy(alpha = 0.45f), RoundedCornerShape(6.dp))
+            .padding(horizontal = 8.dp, vertical = 4.dp),
+    ) {
+        Text(
+            "$w×$h@$hz   ${s[0].roundToInt()} fps   ${"%.1f".format(s[1])} Mb/s",
+            color = Color.White,
+            fontFamily = FontFamily.Monospace,
+            fontSize = 12.sp,
+        )
+        videoFeedLine(s)?.let { feed ->
+            Text(
+                feed,
+                color = Color.White,
+                fontFamily = FontFamily.Monospace,
+                fontSize = 12.sp,
+            )
+        }
+        if (latValid) {
+            val tag = if (skew) "" else " (same-host)"
+            Text(
+                "capture→client ${"%.1f".format(s[2])}/${"%.1f".format(s[3])} ms p50/p95$tag",
+                color = Color.White,
+                fontFamily = FontFamily.Monospace,
+                fontSize = 12.sp,
+            )
+        }
+        if (dropped > 0) {
+            Text(
+                "dropped $dropped",
+                color = Color(0xFFFFB0B0),
+                fontFamily = FontFamily.Monospace,
+                fontSize = 12.sp,
+            )
+        }
+    }
+}
+
+/**
+ * Format the negotiated video-feed descriptor from the trailing four stats doubles
+ * `[bitDepth, colorPrimaries, colorTransfer, chromaFormatIdc]`, e.g.
+ * `HEVC · 10-bit · HDR (BT.2020 PQ) · 4:2:0`. Returns `null` on a pre-video-feed layout (< 14 doubles)
+ * so the overlay simply omits the line. The codes are CICP / H.273: transfer 16 = PQ, 18 = HLG (else
+ * SDR); primaries 9 = BT.2020, 1 = BT.709; chroma_format_idc 1 = 4:2:0, 2 = 4:2:2, 3 = 4:4:4. The
+ * Android decoder is always HEVC (`video/hevc`).
+ */
+private fun videoFeedLine(s: DoubleArray): String? {
+    if (s.size < 14) return null
+    val bitDepth = s[10].toInt()
+    val primaries = s[11].toInt()
+    val transfer = s[12].toInt()
+    val chromaIdc = s[13].toInt()
+    val depthLabel = if (bitDepth > 0) "$bitDepth-bit" else "8-bit"
+    val (dynamicRange, colorSpace) = when (transfer) {
+        16 -> "HDR" to "BT.2020 PQ"
+        18 -> "HDR" to "BT.2020 HLG"
+        else -> "SDR" to if (primaries == 9) "BT.2020" else "BT.709"
+    }
+    val chromaLabel = when (chromaIdc) {
+        3 -> "4:4:4"
+        2 -> "4:2:2"
+        else -> "4:2:0"
+    }
+    return "HEVC · $depthLabel · $dynamicRange ($colorSpace) · $chromaLabel"
+}

clients/android/app/src/main/kotlin/io/unom/punktfunk/StreamScreen.kt

@@ -7,15 +7,9 @@ import android.view.SurfaceHolder
 import android.view.SurfaceView
 import android.view.WindowManager
 import androidx.activity.compose.BackHandler
-import androidx.compose.foundation.background
-import androidx.compose.foundation.gestures.awaitEachGesture
-import androidx.compose.foundation.gestures.awaitFirstDown
 import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
@@ -25,12 +19,9 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.text.font.FontFamily
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
 import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.content.ContextCompat
 import androidx.core.view.WindowCompat
@@ -41,25 +32,6 @@ import io.unom.punktfunk.kit.GamepadFeedback
 import io.unom.punktfunk.kit.NativeBridge
 import java.util.concurrent.atomic.AtomicBoolean
 import kotlinx.coroutines.delay
-import kotlin.math.abs
-import kotlin.math.hypot
-import kotlin.math.roundToInt
-
-// Touch-gesture tuning (px / ms). TAP_SLOP: movement under this still counts as a tap, not a drag.
-// TAP_DRAG_MS: a new touch within this long after a tap starts a left-button drag. SCROLL_DIV: px of
-// two-finger pan per wheel notch (smaller = faster scroll).
-private const val TAP_SLOP = 12f
-private const val TAP_DRAG_MS = 250L
-private const val SCROLL_DIV = 4f
-
-// Trackpad-mode pointer ballistics (relative one-finger motion). POINTER_SENS: base finger-px →
-// host-px gain (~1:1, never twitchy). The rest is mild acceleration so a flick crosses the screen
-// while a slow drag stays precise: above ACCEL_SPEED_FLOOR px/ms the gain ramps by ACCEL_GAIN per
-// px/ms, capped at ACCEL_MAX (so a fast swipe can't fling the cursor uncontrollably).
-private const val POINTER_SENS = 1.3f
-private const val ACCEL_GAIN = 0.6f
-private const val ACCEL_SPEED_FLOOR = 0.3f
-private const val ACCEL_MAX = 3.0f
 
 @Composable
 fun StreamScreen(handle: Long, micEnabled: Boolean, onDisconnect: () -> Unit) {
@@ -76,19 +48,26 @@ fun StreamScreen(handle: Long, micEnabled: Boolean, onDisconnect: () -> Unit) {
         Manifest.permission.RECORD_AUDIO,
     ) == PackageManager.PERMISSION_GRANTED
 
-    // Live decode stats for the HUD. Poll once a second for the whole stream (cheap, and each call
+    // Live decode stats for the HUD. `showStats` gates the whole pipeline: the native per-frame
-    // drains+resets the native window so it never grows unbounded even while the overlay is hidden);
+    // sampling (nativeSetVideoStatsEnabled — hidden HUD costs one atomic load per frame) AND the
-    // `showStats` only gates rendering. A 3-finger tap toggles it live; the default comes from Settings.
+    // 1 s poll loop, which only runs while the overlay is visible. Enabling resets the native
+    // window, so re-showing never renders stale data. A 3-finger tap toggles it live; the default
+    // comes from Settings.
     val initialSettings = remember { SettingsStore(context).load() }
     var stats by remember { mutableStateOf<DoubleArray?>(null) }
     var showStats by remember { mutableStateOf(initialSettings.statsHudEnabled) }
     // Touch model is fixed per session (re-keys the gesture handler below if it ever changes).
     val trackpad = initialSettings.trackpadMode
-    LaunchedEffect(handle) {
+    LaunchedEffect(handle, showStats) {
+        NativeBridge.nativeSetVideoStatsEnabled(handle, showStats)
+        if (showStats) {
             while (true) {
                 delay(1000)
                 stats = NativeBridge.nativeVideoStats(handle)
             }
+        } else {
+            stats = null // drop the last snapshot so a re-show never flashes stale numbers
+        }
     }
 
     // One-shot teardown guard. Both the SurfaceView callback and DisposableEffect tear down on the
@@ -169,240 +148,12 @@ fun StreamScreen(handle: Long, micEnabled: Boolean, onDisconnect: () -> Unit) {
         if (showStats) {
             stats?.let { StatsOverlay(it, Modifier.align(Alignment.TopStart).padding(12.dp)) }
         }
-        // Touch → mouse. Two models, chosen by the Trackpad-mode setting:
+        // Touch → mouse (trackpad vs. direct pointing + the shared gesture vocabulary — see
-        //  • trackpad (default): the cursor STAYS where it is on touch-down and moves by the finger's
+        // streamTouchInput in TouchInput.kt).
-        //    relative delta (MouseMove) with mild pointer acceleration — swipe to nudge, lift and
-        //    re-swipe to walk it across, tap to click where it is. This is what makes the cursor
-        //    reachable on a small screen.
-        //  • direct (opt-out): the cursor jumps to the finger and follows it (MouseMoveAbs,
-        //    host-normalized against the overlay size), the old "direct pointing" behaviour.
-        // Both share the same gesture vocabulary: tap = left click; two-finger tap = right click;
-        // two-finger drag = scroll; tap-then-press-and-drag = left-drag (text selection / moving
-        // windows); three-finger tap = toggle the stats HUD.
         Box(
             Modifier.fillMaxSize().pointerInput(handle, trackpad) {
-                var lastTapUp = 0L
+                streamTouchInput(handle, trackpad, onToggleStats = { showStats = !showStats })
-                var lastTapX = 0f
-                var lastTapY = 0f
-                fun moveAbs(x: Float, y: Float) {
-                    val sw = size.width
-                    val sh = size.height
-                    if (sw <= 0 || sh <= 0) return
-                    NativeBridge.nativeSendPointerAbs(
-                        handle,
-                        x.coerceIn(0f, (sw - 1).toFloat()).roundToInt(),
-                        y.coerceIn(0f, (sh - 1).toFloat()).roundToInt(),
-                        sw,
-                        sh,
-                    )
-                }
-                awaitEachGesture {
-                    val down = awaitFirstDown(requireUnconsumed = false)
-                    val startX = down.position.x
-                    val startY = down.position.y
-                    // A touch landing just after a quick tap nearby = tap-and-drag: hold the left
-                    // button for this whole gesture (laptop-trackpad convention).
-                    val isDrag = down.uptimeMillis - lastTapUp < TAP_DRAG_MS &&
-                        abs(startX - lastTapX) < TAP_SLOP && abs(startY - lastTapY) < TAP_SLOP
-                    lastTapUp = 0L // consume the arming either way
-                    // Direct mode jumps the cursor to the finger; trackpad mode leaves it put (the
-                    // whole point — you nudge it with swipes instead).
-                    if (!trackpad) moveAbs(startX, startY)
-                    if (isDrag) NativeBridge.nativeSendPointerButton(handle, 1, true)
-
-                    var moved = false
-                    var maxFingers = 1
-                    var scrolling = false
-                    var prevCx = startX
-                    var prevCy = startY
-                    var upTime = down.uptimeMillis
-                    // Trackpad relative-motion state: the tracked finger, its last position/time, and
-                    // the sub-pixel remainder so a slow drag isn't lost to Int truncation.
-                    var trackId = down.id
-                    var prevX = startX
-                    var prevY = startY
-                    var prevT = down.uptimeMillis
-                    var accX = 0f
-                    var accY = 0f
-
-                    while (true) {
-                        val ev = awaitPointerEvent()
-                        val pressed = ev.changes.filter { it.pressed }
-                        if (pressed.isEmpty()) {
-                            upTime = ev.changes.firstOrNull()?.uptimeMillis ?: upTime
-                            break
-                        }
-                        if (pressed.size > maxFingers) maxFingers = pressed.size
-
-                        if (pressed.size >= 2) {
-                            // Two fingers → scroll by the centroid delta; never move the cursor.
-                            val cx = (pressed.sumOf { it.position.x.toDouble() } / pressed.size).toFloat()
-                            val cy = (pressed.sumOf { it.position.y.toDouble() } / pressed.size).toFloat()
-                            if (!scrolling) {
-                                scrolling = true
-                                prevCx = cx
-                                prevCy = cy
-                            }
-                            val sy = ((prevCy - cy) / SCROLL_DIV).toInt() // finger up → wheel up
-                            val sx = ((cx - prevCx) / SCROLL_DIV).toInt()
-                            if (sy != 0) {
-                                NativeBridge.nativeSendScroll(handle, 0, sy * 120)
-                                prevCy = cy
-                                moved = true
-                            }
-                            if (sx != 0) {
-                                NativeBridge.nativeSendScroll(handle, 1, sx * 120)
-                                prevCx = cx
-                                moved = true
-                            }
-                        } else if (!scrolling) {
-                            // One finger (skipped once a gesture turned into a scroll, so dropping
-                            // back to one finger doesn't jerk the cursor).
-                            val p = pressed.firstOrNull { it.id == down.id } ?: pressed.first()
-                            if (abs(p.position.x - startX) > TAP_SLOP ||
-                                abs(p.position.y - startY) > TAP_SLOP
-                            ) {
-                                moved = true
-                            }
-                            if (trackpad) {
-                                // Relative: move by the finger delta × (sensitivity × acceleration),
-                                // carrying the sub-pixel remainder. Re-anchor (zero delta this frame)
-                                // if the tracked finger changed, so lifting one of several fingers
-                                // never jumps the cursor.
-                                if (p.id != trackId) {
-                                    trackId = p.id
-                                    prevX = p.position.x
-                                    prevY = p.position.y
-                                    prevT = p.uptimeMillis
-                                }
-                                val dx = p.position.x - prevX
-                                val dy = p.position.y - prevY
-                                val dt = (p.uptimeMillis - prevT).coerceAtLeast(1L)
-                                prevX = p.position.x
-                                prevY = p.position.y
-                                prevT = p.uptimeMillis
-                                val speed = hypot(dx, dy) / dt // finger px per ms
-                                val accel = (1f + ACCEL_GAIN * (speed - ACCEL_SPEED_FLOOR).coerceAtLeast(0f))
-                                    .coerceAtMost(ACCEL_MAX)
-                                accX += dx * POINTER_SENS * accel
-                                accY += dy * POINTER_SENS * accel
-                                val outX = accX.toInt() // truncates toward zero → remainder kept w/ sign
-                                val outY = accY.toInt()
-                                if (outX != 0 || outY != 0) {
-                                    NativeBridge.nativeSendPointerMove(handle, outX, outY)
-                                    accX -= outX
-                                    accY -= outY
-                                }
-                            } else {
-                                moveAbs(p.position.x, p.position.y) // direct: cursor follows the finger
-                            }
-                        }
-                        ev.changes.forEach { it.consume() }
-                    }
-
-                    if (isDrag) {
-                        NativeBridge.nativeSendPointerButton(handle, 1, false) // end the drag
-                    } else if (!moved) {
-                        when {
-                            maxFingers >= 3 -> showStats = !showStats // in-stream HUD toggle
-                            maxFingers == 2 -> { // two-finger tap → right click
-                                NativeBridge.nativeSendPointerButton(handle, 3, true)
-                                NativeBridge.nativeSendPointerButton(handle, 3, false)
-                            }
-                            else -> { // tap → left click (at the cursor's current spot), arm tap-drag
-                                NativeBridge.nativeSendPointerButton(handle, 1, true)
-                                NativeBridge.nativeSendPointerButton(handle, 1, false)
-                                lastTapUp = upTime
-                                lastTapX = startX
-                                lastTapY = startY
-                            }
-                        }
-                    }
-                }
             },
         )
     }
 }
-
-/**
- * The live stats overlay — mirrors the Apple client's HUD. Reads the 14-double layout from
- * [NativeBridge.nativeVideoStats]:
- * `[fps, mbps, latP50Ms, latP95Ms, latValid, skew, w, h, hz, dropped, bitDepth, colorPrimaries,
- * colorTransfer, chromaFormatIdc]`. The trailing four (present on a current native lib) describe the
- * negotiated video feed and render as a codec/depth/colour/chroma line; older layouts just omit it.
- */
-@Composable
-internal fun StatsOverlay(s: DoubleArray, modifier: Modifier = Modifier) {
-    if (s.size < 10) return
-    val w = s[6].toInt()
-    val h = s[7].toInt()
-    val hz = s[8].toInt()
-    val latValid = s[4] != 0.0
-    val skew = s[5] != 0.0
-    val dropped = s[9].toLong()
-    Column(
-        modifier = modifier
-            .background(Color.Black.copy(alpha = 0.45f), RoundedCornerShape(6.dp))
-            .padding(horizontal = 8.dp, vertical = 4.dp),
-    ) {
-        Text(
-            "$w×$h@$hz   ${s[0].roundToInt()} fps   ${"%.1f".format(s[1])} Mb/s",
-            color = Color.White,
-            fontFamily = FontFamily.Monospace,
-            fontSize = 12.sp,
-        )
-        videoFeedLine(s)?.let { feed ->
-            Text(
-                feed,
-                color = Color.White,
-                fontFamily = FontFamily.Monospace,
-                fontSize = 12.sp,
-            )
-        }
-        if (latValid) {
-            val tag = if (skew) "" else " (same-host)"
-            Text(
-                "capture→client ${"%.1f".format(s[2])}/${"%.1f".format(s[3])} ms p50/p95$tag",
-                color = Color.White,
-                fontFamily = FontFamily.Monospace,
-                fontSize = 12.sp,
-            )
-        }
-        if (dropped > 0) {
-            Text(
-                "dropped $dropped",
-                color = Color(0xFFFFB0B0),
-                fontFamily = FontFamily.Monospace,
-                fontSize = 12.sp,
-            )
-        }
-    }
-}
-
-/**
- * Format the negotiated video-feed descriptor from the trailing four stats doubles
- * `[bitDepth, colorPrimaries, colorTransfer, chromaFormatIdc]`, e.g.
- * `HEVC · 10-bit · HDR (BT.2020 PQ) · 4:2:0`. Returns `null` on a pre-video-feed layout (< 14 doubles)
- * so the overlay simply omits the line. The codes are CICP / H.273: transfer 16 = PQ, 18 = HLG (else
- * SDR); primaries 9 = BT.2020, 1 = BT.709; chroma_format_idc 1 = 4:2:0, 2 = 4:2:2, 3 = 4:4:4. The
- * Android decoder is always HEVC (`video/hevc`).
- */
-private fun videoFeedLine(s: DoubleArray): String? {
-    if (s.size < 14) return null
-    val bitDepth = s[10].toInt()
-    val primaries = s[11].toInt()
-    val transfer = s[12].toInt()
-    val chromaIdc = s[13].toInt()
-    val depthLabel = if (bitDepth > 0) "$bitDepth-bit" else "8-bit"
-    val (dynamicRange, colorSpace) = when (transfer) {
-        16 -> "HDR" to "BT.2020 PQ"
-        18 -> "HDR" to "BT.2020 HLG"
-        else -> "SDR" to if (primaries == 9) "BT.2020" else "BT.709"
-    }
-    val chromaLabel = when (chromaIdc) {
-        3 -> "4:4:4"
-        2 -> "4:2:2"
-        else -> "4:2:0"
-    }
-    return "HEVC · $depthLabel · $dynamicRange ($colorSpace) · $chromaLabel"
-}

clients/android/app/src/main/kotlin/io/unom/punktfunk/TouchInput.kt

@@ -0,0 +1,184 @@
+package io.unom.punktfunk
+
+import androidx.compose.foundation.gestures.awaitEachGesture
+import androidx.compose.foundation.gestures.awaitFirstDown
+import androidx.compose.ui.input.pointer.PointerInputScope
+import io.unom.punktfunk.kit.NativeBridge
+import kotlin.math.abs
+import kotlin.math.hypot
+import kotlin.math.roundToInt
+
+// Touch-gesture tuning (px / ms). TAP_SLOP: movement under this still counts as a tap, not a drag.
+// TAP_DRAG_MS: a new touch within this long after a tap starts a left-button drag. SCROLL_DIV: px of
+// two-finger pan per wheel notch (smaller = faster scroll).
+private const val TAP_SLOP = 12f
+private const val TAP_DRAG_MS = 250L
+private const val SCROLL_DIV = 4f
+
+// Trackpad-mode pointer ballistics (relative one-finger motion). POINTER_SENS: base finger-px →
+// host-px gain (~1:1, never twitchy). The rest is mild acceleration so a flick crosses the screen
+// while a slow drag stays precise: above ACCEL_SPEED_FLOOR px/ms the gain ramps by ACCEL_GAIN per
+// px/ms, capped at ACCEL_MAX (so a fast swipe can't fling the cursor uncontrollably).
+private const val POINTER_SENS = 1.3f
+private const val ACCEL_GAIN = 0.6f
+private const val ACCEL_SPEED_FLOOR = 0.3f
+private const val ACCEL_MAX = 3.0f
+
+/**
+ * Touch → mouse, run inside the stream overlay's `pointerInput`. Two models, chosen by the
+ * Trackpad-mode setting:
+ *  * trackpad (default): the cursor STAYS where it is on touch-down and moves by the finger's
+ *    relative delta (MouseMove) with mild pointer acceleration — swipe to nudge, lift and
+ *    re-swipe to walk it across, tap to click where it is. This is what makes the cursor
+ *    reachable on a small screen.
+ *  * direct (opt-out): the cursor jumps to the finger and follows it (MouseMoveAbs,
+ *    host-normalized against the overlay size), the old "direct pointing" behaviour.
+ *
+ * Both share the same gesture vocabulary: tap = left click; two-finger tap = right click;
+ * two-finger drag = scroll; tap-then-press-and-drag = left-drag (text selection / moving
+ * windows); three-finger tap = [onToggleStats] (the stats HUD).
+ */
+internal suspend fun PointerInputScope.streamTouchInput(
+    handle: Long,
+    trackpad: Boolean,
+    onToggleStats: () -> Unit,
+) {
+    var lastTapUp = 0L
+    var lastTapX = 0f
+    var lastTapY = 0f
+    fun moveAbs(x: Float, y: Float) {
+        val sw = size.width
+        val sh = size.height
+        if (sw <= 0 || sh <= 0) return
+        NativeBridge.nativeSendPointerAbs(
+            handle,
+            x.coerceIn(0f, (sw - 1).toFloat()).roundToInt(),
+            y.coerceIn(0f, (sh - 1).toFloat()).roundToInt(),
+            sw,
+            sh,
+        )
+    }
+    awaitEachGesture {
+        val down = awaitFirstDown(requireUnconsumed = false)
+        val startX = down.position.x
+        val startY = down.position.y
+        // A touch landing just after a quick tap nearby = tap-and-drag: hold the left
+        // button for this whole gesture (laptop-trackpad convention).
+        val isDrag = down.uptimeMillis - lastTapUp < TAP_DRAG_MS &&
+            abs(startX - lastTapX) < TAP_SLOP && abs(startY - lastTapY) < TAP_SLOP
+        lastTapUp = 0L // consume the arming either way
+        // Direct mode jumps the cursor to the finger; trackpad mode leaves it put (the
+        // whole point — you nudge it with swipes instead).
+        if (!trackpad) moveAbs(startX, startY)
+        if (isDrag) NativeBridge.nativeSendPointerButton(handle, 1, true)
+
+        var moved = false
+        var maxFingers = 1
+        var scrolling = false
+        var prevCx = startX
+        var prevCy = startY
+        var upTime = down.uptimeMillis
+        // Trackpad relative-motion state: the tracked finger, its last position/time, and
+        // the sub-pixel remainder so a slow drag isn't lost to Int truncation.
+        var trackId = down.id
+        var prevX = startX
+        var prevY = startY
+        var prevT = down.uptimeMillis
+        var accX = 0f
+        var accY = 0f
+
+        while (true) {
+            val ev = awaitPointerEvent()
+            val pressed = ev.changes.filter { it.pressed }
+            if (pressed.isEmpty()) {
+                upTime = ev.changes.firstOrNull()?.uptimeMillis ?: upTime
+                break
+            }
+            if (pressed.size > maxFingers) maxFingers = pressed.size
+
+            if (pressed.size >= 2) {
+                // Two fingers → scroll by the centroid delta; never move the cursor.
+                val cx = (pressed.sumOf { it.position.x.toDouble() } / pressed.size).toFloat()
+                val cy = (pressed.sumOf { it.position.y.toDouble() } / pressed.size).toFloat()
+                if (!scrolling) {
+                    scrolling = true
+                    prevCx = cx
+                    prevCy = cy
+                }
+                val sy = ((prevCy - cy) / SCROLL_DIV).toInt() // finger up → wheel up
+                val sx = ((cx - prevCx) / SCROLL_DIV).toInt()
+                if (sy != 0) {
+                    NativeBridge.nativeSendScroll(handle, 0, sy * 120)
+                    prevCy = cy
+                    moved = true
+                }
+                if (sx != 0) {
+                    NativeBridge.nativeSendScroll(handle, 1, sx * 120)
+                    prevCx = cx
+                    moved = true
+                }
+            } else if (!scrolling) {
+                // One finger (skipped once a gesture turned into a scroll, so dropping
+                // back to one finger doesn't jerk the cursor).
+                val p = pressed.firstOrNull { it.id == down.id } ?: pressed.first()
+                if (abs(p.position.x - startX) > TAP_SLOP ||
+                    abs(p.position.y - startY) > TAP_SLOP
+                ) {
+                    moved = true
+                }
+                if (trackpad) {
+                    // Relative: move by the finger delta × (sensitivity × acceleration),
+                    // carrying the sub-pixel remainder. Re-anchor (zero delta this frame)
+                    // if the tracked finger changed, so lifting one of several fingers
+                    // never jumps the cursor.
+                    if (p.id != trackId) {
+                        trackId = p.id
+                        prevX = p.position.x
+                        prevY = p.position.y
+                        prevT = p.uptimeMillis
+                    }
+                    val dx = p.position.x - prevX
+                    val dy = p.position.y - prevY
+                    val dt = (p.uptimeMillis - prevT).coerceAtLeast(1L)
+                    prevX = p.position.x
+                    prevY = p.position.y
+                    prevT = p.uptimeMillis
+                    val speed = hypot(dx, dy) / dt // finger px per ms
+                    val accel = (1f + ACCEL_GAIN * (speed - ACCEL_SPEED_FLOOR).coerceAtLeast(0f))
+                        .coerceAtMost(ACCEL_MAX)
+                    accX += dx * POINTER_SENS * accel
+                    accY += dy * POINTER_SENS * accel
+                    val outX = accX.toInt() // truncates toward zero → remainder kept w/ sign
+                    val outY = accY.toInt()
+                    if (outX != 0 || outY != 0) {
+                        NativeBridge.nativeSendPointerMove(handle, outX, outY)
+                        accX -= outX
+                        accY -= outY
+                    }
+                } else {
+                    moveAbs(p.position.x, p.position.y) // direct: cursor follows the finger
+                }
+            }
+            ev.changes.forEach { it.consume() }
+        }
+
+        if (isDrag) {
+            NativeBridge.nativeSendPointerButton(handle, 1, false) // end the drag
+        } else if (!moved) {
+            when {
+                maxFingers >= 3 -> onToggleStats() // in-stream HUD toggle
+                maxFingers == 2 -> { // two-finger tap → right click
+                    NativeBridge.nativeSendPointerButton(handle, 3, true)
+                    NativeBridge.nativeSendPointerButton(handle, 3, false)
+                }
+                else -> { // tap → left click (at the cursor's current spot), arm tap-drag
+                    NativeBridge.nativeSendPointerButton(handle, 1, true)
+                    NativeBridge.nativeSendPointerButton(handle, 1, false)
+                    lastTapUp = upTime
+                    lastTapX = startX
+                    lastTapY = startY
+                }
+            }
+        }
+    }
+}

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/NativeBridge.kt

@@ -114,6 +114,14 @@ object NativeBridge {
      */
     external fun nativeVideoStats(handle: Long): DoubleArray?
 
+    /**
+     * Gate per-frame stats sampling on the HUD being visible: while disabled the decode thread
+     * skips the per-AU clock read + lock, so toggle this with the overlay (and only poll
+     * [nativeVideoStats] while it's on). Enabling resets the measurement window — no stale data.
+     * Sticky for the session (survives video stop/start). No-op on `0`.
+     */
+    external fun nativeSetVideoStatsEnabled(handle: Long, enabled: Boolean)
+
     /**
      * Start host→client audio: Opus decode → jitter ring → AAudio (LowLatency), all in Rust. No-op
      * if already started. Best-effort — a failure leaves video streaming.

clients/android/native/Cargo.toml

@@ -27,8 +27,8 @@ log = "0.4"
 mdns-sd = "0.20"
 
 # Android-only deps. Gated so `cargo build --workspace` on the Linux/macOS dev boxes + CI still
-# compiles this crate (as a host cdylib) — the Android-framework glue (logging now; AMediaCodec via
+# compiles this crate (as a host cdylib) — the Android-framework glue (logging, AMediaCodec + AAudio
-# `ndk` and Oboe/Opus audio later) is only pulled in for the real `*-linux-android` targets.
+# via `ndk`, the Opus codec) is only pulled in for the real `*-linux-android` targets.
 [target.'cfg(target_os = "android")'.dependencies]
 android_logger = "0.14"
 # NDK bindings. "media" = AMediaCodec/ANativeWindow (video); "audio" = AAudio (audio playback).

clients/android/native/src/audio.rs

@@ -129,21 +129,32 @@ impl AudioPlayback {
         let jitter_headroom = JITTER_HEADROOM_MS * ms;
         let hard_cap_max = HARD_CAP_MS * ms;
         let counters = Arc::new(Counters::default());
+
+        // One open attempt at a given sharing mode. Everything the realtime callback captures
+        // (channels, ring, prime state) is rebuilt per attempt — `open_stream` consumes the builder
+        // AND the callback, so nothing survives a failed try to reuse.
+        let try_open = |sharing: AudioSharingMode| -> ndk::audio::Result<(
+            AudioStream,
+            SyncSender<Vec<f32>>,
+            Receiver<Vec<f32>>,
+        )> {
             let (tx, rx) = sync_channel::<Vec<f32>>(RING_CHUNKS);
-        // Recycle free-list: drained PCM buffers go BACK to the decode thread to be refilled, so the
+            // Recycle free-list: drained PCM buffers go BACK to the decode thread to be refilled, so
-        // realtime callback never frees heap (Android's Scudo allocator has unbounded free() tail
+            // the realtime callback never frees heap (Android's Scudo allocator has unbounded free()
-        // latency — a free on the audio thread is an XRun = a click) and the decode thread rarely
+            // tail latency — a free on the audio thread is an XRun = a click) and the decode thread
-        // allocates. Same depth as the data channel.
+            // rarely allocates. Same depth as the data channel.
             let (free_tx, free_rx) = sync_channel::<Vec<f32>>(RING_CHUNKS);
 
-        // Realtime consumer state, owned by the callback (FnMut) — no lock: AAudio calls it from a
+            // Realtime consumer state, owned by the callback (FnMut) — no lock: AAudio calls it from
-        // single high-priority thread, and the decode thread only touches `tx`/`free_rx`.
+            // a single high-priority thread, and the decode thread only touches `tx`/`free_rx`.
             let cb_counters = counters.clone();
-        // Pre-reserve the ring so `extend` never reallocates on the realtime thread. Worst transient
+            // Pre-reserve the ring so `extend` never reallocates on the realtime thread. Worst
-        // before the trim below = the hard cap plus one full channel of 5 ms (480-f32) frames — the
+            // transient before the trim below = the hard cap plus one full channel of 5 ms (480-f32)
-        // punktfunk protocol always sends 5 ms Opus frames (host `audio_thread`); a larger frame
+            // frames — the punktfunk protocol always sends 5 ms Opus frames (host `audio_thread`); a
-        // would force a one-time realloc, asserted (not silently corrupted) in `decode_loop`.
+            // larger frame would force a one-time realloc, asserted (not silently corrupted) in
-        let mut ring: VecDeque<f32> = VecDeque::with_capacity(hard_cap_max + RING_CHUNKS * 5 * ms);
+            // `decode_loop`.
+            let mut ring: VecDeque<f32> =
+                VecDeque::with_capacity(hard_cap_max + RING_CHUNKS * 5 * ms);
             let mut primed = false;
             let mut empties: u32 = 0; // consecutive empty callbacks (de-prime hysteresis)
             let mut cb_count: u32 = 0; // callbacks since open (throttles the XRun grow check)
@@ -152,16 +163,18 @@ impl AudioPlayback {
                 let want = num_frames as usize * channels;
                 // SAFETY: AAudio provides `num_frames * channel_count` F32 slots at `data`.
                 let out = unsafe { std::slice::from_raw_parts_mut(data as *mut f32, want) };
-            // Drain decoded chunks into the ring WITHOUT freeing on the RT thread: `drain(..)` empties
+                // Drain decoded chunks into the ring WITHOUT freeing on the RT thread: `drain(..)`
-            // each Vec but keeps its capacity, then the empty buffer is handed back for reuse. The
+                // empties each Vec but keeps its capacity, then the empty buffer is handed back for
-            // only RT-thread free is the rare case where the recycle channel is momentarily full.
+                // reuse. The only RT-thread free is the rare case where the recycle channel is
+                // momentarily full.
                 while let Ok(mut chunk) = rx.try_recv() {
                     ring.extend(chunk.drain(..));
                     let _ = free_tx.try_send(chunk);
                 }
-            // Jitter buffer: prime to ~40 ms (prime_floor) before playing and after a sustained drain;
+                // Jitter buffer: prime to ~40 ms (prime_floor) before playing and after a sustained
-            // drop-oldest only above a wide ~120 ms band. Decoupled from the AAudio burst `want` (tiny
+                // drain; drop-oldest only above a wide ~120 ms band. Decoupled from the AAudio burst
-            // on the LowLatency MMAP path) so the depth doesn't collapse to a single quantum.
+                // `want` (tiny on the LowLatency MMAP path) so the depth doesn't collapse to a single
+                // quantum.
                 let target = (3 * want).clamp(prime_floor, prime_ceil);
                 let hard_cap = (target + jitter_headroom).min(hard_cap_max);
                 while ring.len() > hard_cap {
@@ -181,9 +194,9 @@ impl AudioPlayback {
                     out.fill(0.0);
                     cb_counters.underruns.fetch_add(1, Ordering::Relaxed);
                 }
-            // Re-prime only after a RUN of empty callbacks, not a single transient one — otherwise
+                // Re-prime only after a RUN of empty callbacks, not a single transient one —
-            // every momentary drain costs a fresh 40 ms silence (the old behaviour, self-inflicted
+                // otherwise every momentary drain costs a fresh 40 ms silence (the old behaviour,
-            // crackle on any jitter spike).
+                // self-inflicted crackle on any jitter spike).
                 if ring.is_empty() {
                     empties += 1;
                     if empties >= DEPRIME_AFTER_CALLBACKS {
@@ -195,9 +208,10 @@ impl AudioPlayback {
                 cb_counters
                     .ring_depth
                     .store(ring.len() as u64, Ordering::Relaxed);
-            // Google's AAudio anti-glitch technique: when the device reports new XRuns, grow the HW
+                // Google's AAudio anti-glitch technique: when the device reports new XRuns, grow the
-            // buffer by one burst (up to capacity). getXRunCount + setBufferSizeInFrames are both
+                // HW buffer by one burst (up to capacity). getXRunCount + setBufferSizeInFrames are
-            // callback-safe / non-blocking, and set clamps to capacity so it self-limits. Throttled.
+                // both callback-safe / non-blocking, and set clamps to capacity so it self-limits.
+                // Throttled.
                 cb_count = cb_count.wrapping_add(1);
                 if cb_count % XRUN_CHECK_EVERY == 0 {
                     let xr = s.x_run_count();
@@ -212,9 +226,7 @@ impl AudioPlayback {
                 AudioCallbackResult::Continue
             };
 
-        let stream = AudioStreamBuilder::new()
+            let stream = AudioStreamBuilder::new()?
-            .map_err(|e| log::error!("audio: AudioStreamBuilder::new: {e}"))
-            .ok()?
                 .direction(AudioDirection::Output)
                 .sample_rate(SAMPLE_RATE)
                 // The wire order (FL FR FC LFE RL RR SL SR) is the standard AAudio/Android channel
@@ -224,14 +236,33 @@ impl AudioPlayback {
                 .channel_count(channels as i32)
                 .format(AudioFormat::PCM_Float)
                 .performance_mode(AudioPerformanceMode::LowLatency)
-            .sharing_mode(AudioSharingMode::Shared)
+                .sharing_mode(sharing)
                 .data_callback(Box::new(callback))
                 .error_callback(Box::new(|_s, e| {
                     log::warn!("audio: AAudio error (device reroute/disconnect?): {e:?}");
                 }))
-            .open_stream()
+                .open_stream()?;
-            .map_err(|e| log::error!("audio: open_stream: {e}"))
+            Ok((stream, tx, free_rx))
-            .ok()?;
+        };
+
+        // Exclusive first — MMAP-exclusive is AAudio's lowest-latency path (once proven on-device it
+        // may also allow lowering the jitter-ring depths above; those stay put pending crackle
+        // testing) — and fall back to Shared when the device refuses (no MMAP, output claimed, …).
+        // The started-log below prints the mode the device actually GRANTED (`share=`): AAudio may
+        // still resolve an Exclusive request to Shared.
+        let (stream, tx, free_rx) = match try_open(AudioSharingMode::Exclusive) {
+            Ok(opened) => opened,
+            Err(e) => {
+                log::info!("audio: Exclusive open failed ({e}) — retrying Shared");
+                match try_open(AudioSharingMode::Shared) {
+                    Ok(opened) => opened,
+                    Err(e) => {
+                        log::error!("audio: open_stream: {e}");
+                        return None;
+                    }
+                }
+            }
+        };
 
         if let Err(e) = stream.request_start() {
             log::error!("audio: request_start: {e}");

clients/android/native/src/decode.rs

@@ -14,6 +14,7 @@ use ndk::media::media_format::MediaFormat;
 use ndk::native_window::{FrameRateCompatibility, NativeWindow};
 use punktfunk_core::client::NativeClient;
 use punktfunk_core::error::PunktfunkError;
+use punktfunk_core::session::Frame;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
 use std::time::{Duration, Instant};
@@ -53,6 +54,9 @@ pub fn run(
     );
     // Ask for the low-latency decode path where the decoder supports it (no reordering buffer).
     format.set_i32("low-latency", 1);
+    // Best-effort vendor twin of the standard key: older Qualcomm decoders only honor their own
+    // extension. Unknown keys are ignored by other vendors' codecs, so this is safe to set blind.
+    format.set_i32("vendor.qti-ext-dec-low-latency.enable", 1);
     // Advisory low-latency hints (KEY_PRIORITY / KEY_OPERATING_RATE), ignored where unsupported:
     // realtime priority + the target frame rate, so vendor decoders (e.g. Qualcomm) run at full
     // clocks instead of a power-saving cadence that adds dequeue latency.
@@ -102,6 +106,11 @@ pub fn run(
 
     let mut fed: u64 = 0;
     let mut rendered: u64 = 0;
+    let mut discarded: u64 = 0;
+    // The AU waiting for a free codec input buffer. `feed` is non-blocking; on transient input
+    // pressure the AU stays parked here instead of being dropped (a drop forces a keyframe
+    // round-trip) and we only pop the next one once it's queued.
+    let mut pending: Option<Frame> = None;
     // Loss recovery: watch the host→client unrecoverable-drop count and ask for an IDR when it
     // climbs.
     let mut last_dropped = client.frames_dropped();
@@ -112,7 +121,13 @@ pub fn run(
     // The dataspace we've signalled on the Surface so far (None = default/SDR). Set reactively once
     // the decoder reports an HDR stream (see `drain`); avoids re-applying every format event.
     let mut applied_ds: Option<DataSpace> = None;
+    // One thread feeds AND drains: the NDK AMediaCodec wrapper isn't documented thread-safe for
+    // cross-thread feed/drain, so instead of splitting threads the loop decouples the two — input
+    // dequeue is non-blocking (never stalls presentation of already-decoded frames) and the only
+    // blocking wait is a short output dequeue while input is backed up (decoder progress is exactly
+    // what frees the next input buffer).
     while !shutdown.load(Ordering::Relaxed) {
+        if pending.is_none() {
             match client.next_frame(Duration::from_millis(5)) {
                 Ok(frame) => {
                     if fed == 0 {
@@ -123,18 +138,44 @@ pub fn run(
                             &p[..p.len().min(6)]
                         );
                     }
-                fed += 1;
+                    // HUD stat: capture→client-receipt latency = client_now + (host−client) −
-                // HUD stat: capture→client-receipt latency = client_now + (host−client) − capture_pts.
+                    // capture_pts. Gated on the HUD being visible — `enabled` first so the hidden
-                let lat_ns = now_realtime_ns() + clock_offset as i128 - frame.pts_ns as i128;
+                    // steady state skips the wall-clock read and the lock entirely.
-                let lat_us =
+                    if stats.enabled() {
-                    (lat_ns > 0 && lat_ns < 10_000_000_000).then_some((lat_ns / 1000) as u64);
+                        let lat_ns =
+                            now_realtime_ns() + clock_offset as i128 - frame.pts_ns as i128;
+                        let lat_us = (lat_ns > 0 && lat_ns < 10_000_000_000)
+                            .then_some((lat_ns / 1000) as u64);
                         stats.note(frame.data.len(), lat_us, clock_offset != 0);
-                feed(&codec, &frame.data, frame.pts_ns / 1000);
+                    }
+                    pending = Some(frame);
                 }
                 Err(PunktfunkError::NoFrame) => {} // timeout — still drain output below
                 Err(_) => break,                   // session closed
             }
-        rendered += drain(&codec, &window, &mut applied_ds);
+        }
+        if let Some(frame) = pending.take() {
+            if feed(&codec, &frame.data, frame.pts_ns / 1000) {
+                fed += 1;
+                if fed % 300 == 0 {
+                    log::info!("decode: fed={fed} rendered={rendered} discarded={discarded}");
+                }
+            } else {
+                // No input buffer free — transient back-pressure. Keep the AU and let `drain` block
+                // briefly below; a released output buffer is what recycles an input slot.
+                pending = Some(frame);
+            }
+        }
+        // Drain every iteration. When input is blocked, wait ~2 ms on output so the loop rides
+        // decoder progress instead of busy-spinning against a full input queue.
+        let wait = if pending.is_some() {
+            Duration::from_millis(2)
+        } else {
+            Duration::ZERO
+        };
+        let (r, d) = drain(&codec, &window, &mut applied_ds, wait);
+        rendered += r;
+        discarded += d;
 
         // Loss recovery: under infinite GOP the only recovery keyframe is one we request. The
         // reassembler drops unrecoverable AUs (frames_dropped); the decoder then conceals the
@@ -152,14 +193,10 @@ pub fn run(
                 log::debug!("decode: requested keyframe (loss recovery, dropped={dropped})");
             }
         }
-
-        if fed > 0 && fed % 300 == 0 {
-            log::info!("decode: fed={fed} rendered={rendered}");
-        }
     }
 
     let _ = codec.stop();
-    log::info!("decode: stopped (fed={fed} rendered={rendered})");
+    log::info!("decode: stopped (fed={fed} rendered={rendered} discarded={discarded})");
 }
 
 /// Wall-clock now in nanoseconds (CLOCK_REALTIME basis), to compare against the host-stamped
@@ -189,9 +226,12 @@ fn boost_thread_priority() {
     }
 }
 
-/// Copy one access unit into a codec input buffer and queue it.
+/// Try to copy one access unit into a codec input buffer and queue it, without blocking. Returns
-fn feed(codec: &MediaCodec, au: &[u8], pts_us: u64) {
+/// `false` only on `TryAgainLater` (no input buffer free) — the caller keeps the AU pending and
-    match codec.dequeue_input_buffer(Duration::from_millis(10)) {
+/// retries; a hard dequeue/queue error counts as consumed (retrying can't salvage the AU, and
+/// parking it forever would wedge the loop on a broken codec).
+fn feed(codec: &MediaCodec, au: &[u8], pts_us: u64) -> bool {
+    match codec.dequeue_input_buffer(Duration::ZERO) {
         Ok(DequeuedInputBufferResult::Buffer(mut buf)) => {
             let n = {
                 let dst = buf.buffer_mut();
@@ -203,41 +243,63 @@ fn feed(codec: &MediaCodec, au: &[u8], pts_us: u64) {
                         dst.len()
                     );
                 }
-                for (slot, &b) in dst.iter_mut().zip(&au[..n]) {
+                // SAFETY: `au` and `dst` are distinct allocations (wire AU vs. codec buffer), both
-                    slot.write(b);
+                // valid for `n` bytes; `MaybeUninit<u8>` is layout-identical to `u8`, so the cast
+                // write initializes exactly `dst[..n]`.
+                unsafe {
+                    std::ptr::copy_nonoverlapping(au.as_ptr(), dst.as_mut_ptr().cast::<u8>(), n);
                 }
                 n
             };
             if let Err(e) = codec.queue_input_buffer(buf, 0, n, pts_us, 0) {
                 log::warn!("decode: queue_input_buffer: {e}");
             }
+            true
         }
-        Ok(DequeuedInputBufferResult::TryAgainLater) => {
+        Ok(DequeuedInputBufferResult::TryAgainLater) => false, // caller keeps the AU pending
-            // No input buffer free right now; the AU is dropped (FEC/keyframes recover).
+        Err(e) => {
+            log::warn!("decode: dequeue_input_buffer: {e}");
+            true
         }
-        Err(e) => log::warn!("decode: dequeue_input_buffer: {e}"),
     }
 }
 
-/// Release any ready output buffers to the surface (render = true), latency-first. Returns the
+/// Dequeue every ready output buffer and present only the NEWEST (render = true), discarding the
-/// number of frames presented. Also reacts to `OutputFormatChanged` to signal HDR on the Surface.
+/// rest (render = false) — when decode falls behind, a back-to-back burst of stale frames on glass
-fn drain(codec: &MediaCodec, window: &NativeWindow, applied_ds: &mut Option<DataSpace>) -> u64 {
+/// is worse than skipping straight to the freshest one (the Apple client's 1-slot newest-ready
-    let mut n = 0;
+/// ring, ported). `first_wait` is the timeout for the first dequeue only: zero normally, ~2 ms when
+/// the caller's input is blocked so the loop waits on decoder progress instead of busy-spinning.
+/// Returns `(rendered, discarded)`. Also reacts to `OutputFormatChanged` (which can interleave
+/// between buffers — handled without losing the held buffer) to signal HDR on the Surface.
+fn drain(
+    codec: &MediaCodec,
+    window: &NativeWindow,
+    applied_ds: &mut Option<DataSpace>,
+    first_wait: Duration,
+) -> (u64, u64) {
+    let mut held = None; // newest ready buffer so far, presented after the loop
+    let mut discarded: u64 = 0;
+    let mut wait = first_wait;
     loop {
-        match codec.dequeue_output_buffer(Duration::from_millis(0)) {
+        match codec.dequeue_output_buffer(wait) {
             Ok(DequeuedOutputBufferInfoResult::Buffer(buf)) => {
-                if let Err(e) = codec.release_output_buffer(buf, true) {
+                wait = Duration::ZERO; // only the first dequeue may block
-                    log::warn!("decode: release_output_buffer: {e}");
+                if let Some(stale) = held.replace(buf) {
-                    break;
+                    // A newer frame is ready — drop the held one without rendering.
+                    if let Err(e) = codec.release_output_buffer(stale, false) {
+                        log::warn!("decode: release_output_buffer(discard): {e}");
+                    }
+                    discarded += 1;
                 }
-                n += 1;
             }
             Ok(DequeuedOutputBufferInfoResult::OutputFormatChanged) => {
                 // The decoder has parsed the SPS and now reports the stream's real colour signalling
                 // (the AMediaCodec analogue of VideoToolbox's format description on the Apple client).
                 // If it's HDR (BT.2020 PQ/HLG), tell the Surface so the compositor/display switch to
                 // HDR; SDR streams leave the default dataspace alone. The decoder itself picks a
-                // Main10 path from the SPS — no profile override needed. Keep looping (buffers follow).
+                // Main10 path from the SPS — no profile override needed. Keep looping (buffers
+                // follow, and any held buffer stays held across this event).
+                wait = Duration::ZERO;
                 if let Some(ds) = hdr_dataspace(codec) {
                     if *applied_ds != Some(ds) {
                         match window.set_buffers_data_space(ds) {
@@ -252,7 +314,7 @@ fn drain(codec: &MediaCodec, window: &NativeWindow, applied_ds: &mut Option<Data
                     }
                 }
             }
-            // TryAgainLater / OutputBuffersChanged — nothing to render now.
+            // TryAgainLater / OutputBuffersChanged — nothing more to dequeue now.
             Ok(_) => break,
             Err(e) => {
                 log::warn!("decode: dequeue_output_buffer: {e}");
@@ -260,7 +322,15 @@ fn drain(codec: &MediaCodec, window: &NativeWindow, applied_ds: &mut Option<Data
             }
         }
     }
-    n
+    // Present the newest ready frame, if any.
+    let mut rendered = 0;
+    if let Some(buf) = held {
+        match codec.release_output_buffer(buf, true) {
+            Ok(()) => rendered = 1,
+            Err(e) => log::warn!("decode: release_output_buffer: {e}"),
+        }
+    }
+    (rendered, discarded)
 }
 
 /// Map the decoder's reported output colour to a BT.2020 HDR dataspace, or `None` for SDR. The

clients/android/native/src/lib.rs

@@ -16,10 +16,10 @@
 //! Wi-Fi `MulticastLock` + permission UX, Keystore identity).
 //!
 //! JNI symbols map to `io.unom.punktfunk.kit.NativeBridge` in the `:kit` Gradle module
-//! (`clients/android`). The current surface is the scaffold's native-link proof
+//! (`clients/android`). The surface: the native-link proof (`abiVersion`/`coreVersion`), mDNS host
-//! (`abiVersion`/`coreVersion`) plus the session handle lifecycle in [`session`]; the per-plane
+//! discovery ([`discovery`]), and the session lifecycle in [`session`] — connect/pair + the trust
-//! pumps (video → AMediaCodec, audio → Oboe), input, audio, pairing and mode renegotiation are
+//! surface, the per-plane pumps (video → AMediaCodec, audio ↔ AAudio, mic uplink), input, and
-//! the next milestone (see the TODOs in [`session`]).
+//! rumble/HID feedback ([`feedback`]). Mode renegotiation is still TODO (see [`session`]).
 
 use jni::objects::JObject;
 use jni::sys::jint;

clients/android/native/src/mic.rs

@@ -1,9 +1,12 @@
 //! Android microphone uplink (android-only): capture mic PCM via AAudio (LowLatency **input**),
 //! Opus-encode 20 ms stereo frames, and push them to the host over the connector's mic plane
 //! (`send_mic` → 0xCB datagram). The mirror of [`crate::audio`] in reverse: AAudio's realtime input
-//! callback hands captured interleaved f32 to a channel; a worker thread we own does the Opus encode
+//! callback hands captured interleaved f32 to a channel; a worker thread we own does the Opus
-//! + send (encoding is too heavy for the realtime callback, exactly as decode is on the playback
+//! encode + send (encoding is too heavy for the realtime callback, exactly as decode is on the
-//! side). Format matches the host decoder + the Linux client: 48 kHz **stereo**, 20 ms, Opus VOIP.
+//! playback side). Like the playback path, the realtime callback is allocation-free: captured
+//! bursts are copied into pre-allocated buffers from a recycle free-list (pool empty = drop the
+//! chunk, never allocate on the capture thread). Format matches the host decoder + the Linux
+//! client: 48 kHz **stereo**, 20 ms, Opus VOIP.
 
 use ndk::audio::{
     AudioCallbackResult, AudioDirection, AudioFormat, AudioPerformanceMode, AudioSharingMode,
@@ -13,7 +16,7 @@ use punktfunk_core::client::NativeClient;
 use std::collections::VecDeque;
 use std::ffi::c_void;
 use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
-use std::sync::mpsc::{sync_channel, Receiver, RecvTimeoutError, TrySendError};
+use std::sync::mpsc::{sync_channel, Receiver, RecvTimeoutError, SyncSender, TrySendError};
 use std::sync::Arc;
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
@@ -23,6 +26,10 @@ const SAMPLE_RATE: i32 = 48_000;
 const FRAME_SAMPLES: usize = 960;
 /// Captured-chunk hand-off depth (each ~ one burst); drops on overflow (best-effort uplink).
 const RING_CHUNKS: usize = 64;
+/// Free-list buffer capacity, in interleaved f32 samples: comfortably above a LowLatency input
+/// burst (typically ≤ ~480 frames). A device with larger bursts costs each buffer a one-time grow
+/// on the capture thread, after which the steady state is allocation-free again.
+const CHUNK_CAP_SAMPLES: usize = 1920; // 20 ms stereo
 /// Opus VOIP target bitrate (speech; tunable).
 const MIC_BITRATE: i32 = 64_000;
 
@@ -38,56 +45,109 @@ impl MicCapture {
     /// forwards captured PCM to a channel, then spawn the Opus encode + uplink thread. `None` on
     /// failure (the caller leaves the rest of the session streaming).
     pub fn start(client: Arc<NativeClient>) -> Option<MicCapture> {
-        let (tx, rx) = sync_channel::<Vec<f32>>(RING_CHUNKS);
         let captured = Arc::new(AtomicU64::new(0));
+        // Chunks discarded on the capture thread (free-list empty / encoder lagging); logged
+        // throttled from the encode worker.
+        let dropped = Arc::new(AtomicU64::new(0));
+
+        // One open attempt at a given sharing mode (same pattern as [`crate::audio`]: `open_stream`
+        // consumes the builder AND the callback, so each try rebuilds the channels it captures).
+        let try_open = |sharing: AudioSharingMode| -> ndk::audio::Result<(
+            AudioStream,
+            Receiver<Vec<f32>>,
+            SyncSender<Vec<f32>>,
+        )> {
+            let (tx, rx) = sync_channel::<Vec<f32>>(RING_CHUNKS);
+            // Recycle free-list, mirroring the playback path: the realtime capture callback must
+            // not touch the allocator (Android's Scudo has unbounded malloc/free tail latency — an
+            // allocation here is a missed burst), so it pops a pre-allocated buffer, copies the
+            // burst in and sends it; the encode worker returns drained buffers. Pool empty = DROP
+            // the chunk (counted) rather than allocate.
+            let (free_tx, free_rx) = sync_channel::<Vec<f32>>(RING_CHUNKS);
+            for _ in 0..RING_CHUNKS {
+                let _ = free_tx.try_send(Vec::with_capacity(CHUNK_CAP_SAMPLES));
+            }
             let cb_captured = captured.clone();
+            let cb_dropped = dropped.clone();
+            let cb_free_tx = free_tx.clone(); // returns the buffer when the data channel is full
 
             let callback = move |_s: &AudioStream, data: *mut c_void, num_frames: i32| {
                 let n = num_frames as usize * CHANNELS;
-            // SAFETY: for an input stream AAudio provides `num_frames * channel_count` captured F32
+                // SAFETY: for an input stream AAudio provides `num_frames * channel_count` captured
-            // samples at `data` (read-only for us).
+                // F32 samples at `data` (read-only for us).
                 let inp = unsafe { std::slice::from_raw_parts(data as *const f32, n) };
-            match tx.try_send(inp.to_vec()) {
+                cb_captured.fetch_add(num_frames as u64, Ordering::Relaxed);
-                Ok(()) | Err(TrySendError::Full(_)) => {} // drop-newest if the encoder lags
+                match free_rx.try_recv() {
+                    Ok(mut buf) => {
+                        buf.clear();
+                        buf.extend_from_slice(inp); // retained capacity — no realloc past the first
+                        match tx.try_send(buf) {
+                            Ok(()) => {}
+                            Err(TrySendError::Full(buf)) => {
+                                // Encoder lagging: drop the chunk, hand the buffer straight back.
+                                let _ = cb_free_tx.try_send(buf);
+                                cb_dropped.fetch_add(1, Ordering::Relaxed);
+                            }
                             Err(TrySendError::Disconnected(_)) => return AudioCallbackResult::Stop,
                         }
-            cb_captured.fetch_add(num_frames as u64, Ordering::Relaxed);
+                    }
+                    // Pool empty (every buffer in flight): drop, never allocate on this thread.
+                    Err(_) => {
+                        cb_dropped.fetch_add(1, Ordering::Relaxed);
+                    }
+                }
                 AudioCallbackResult::Continue
             };
 
-        let stream = AudioStreamBuilder::new()
+            let stream = AudioStreamBuilder::new()?
-            .map_err(|e| log::error!("mic: AudioStreamBuilder::new: {e}"))
-            .ok()?
                 .direction(AudioDirection::Input)
                 .sample_rate(SAMPLE_RATE)
                 .channel_count(CHANNELS as i32)
                 .format(AudioFormat::PCM_Float)
                 .performance_mode(AudioPerformanceMode::LowLatency)
-            .sharing_mode(AudioSharingMode::Shared)
+                .sharing_mode(sharing)
                 .data_callback(Box::new(callback))
                 .error_callback(Box::new(|_s, e| {
                     log::warn!("mic: AAudio error (device reroute/disconnect?): {e:?}");
                 }))
-            .open_stream()
+                .open_stream()?;
-            .map_err(|e| log::error!("mic: open_stream (RECORD_AUDIO granted?): {e}"))
+            Ok((stream, rx, free_tx))
-            .ok()?;
+        };
+
+        // Exclusive first — MMAP-exclusive is AAudio's lowest-latency path — falling back to Shared
+        // when the device refuses (no MMAP, mic claimed, …). The started-log below prints the mode
+        // the device actually GRANTED (`share=`).
+        let (stream, rx, free_tx) = match try_open(AudioSharingMode::Exclusive) {
+            Ok(opened) => opened,
+            Err(e) => {
+                log::info!("mic: Exclusive open failed ({e}) — retrying Shared");
+                match try_open(AudioSharingMode::Shared) {
+                    Ok(opened) => opened,
+                    Err(e) => {
+                        log::error!("mic: open_stream (RECORD_AUDIO granted?): {e}");
+                        return None;
+                    }
+                }
+            }
+        };
 
         if let Err(e) = stream.request_start() {
             log::error!("mic: request_start: {e}");
             return None;
         }
         log::info!(
-            "mic: AAudio input started rate={} ch={} fmt={:?}",
+            "mic: AAudio input started rate={} ch={} fmt={:?} share={:?}",
             stream.sample_rate(),
             stream.channel_count(),
             stream.format(),
+            stream.sharing_mode(),
         );
 
         let shutdown = Arc::new(AtomicBool::new(false));
         let sd = shutdown.clone();
         let join = std::thread::Builder::new()
             .name("pf-mic".into())
-            .spawn(move || encode_loop(client, rx, sd, captured))
+            .spawn(move || encode_loop(client, rx, free_tx, sd, captured, dropped))
             .ok();
 
         Some(MicCapture {
@@ -109,11 +169,15 @@ impl Drop for MicCapture {
 }
 
 /// Consumer: drain captured f32 → accumulate → Opus `encode_float` 20 ms stereo frames → `send_mic`.
+/// Drained chunk buffers go back to the callback's free-list; the encode scratch is reused across
+/// frames (only the packet Vec handed to `send_mic` is allocated per frame — it's sent away owned).
 fn encode_loop(
     client: Arc<NativeClient>,
     rx: Receiver<Vec<f32>>,
+    free_tx: SyncSender<Vec<f32>>,
     shutdown: Arc<AtomicBool>,
     captured: Arc<AtomicU64>,
+    dropped: Arc<AtomicU64>,
 ) {
     let mut enc = match opus::Encoder::new(
         SAMPLE_RATE as u32,
@@ -130,6 +194,7 @@ fn encode_loop(
 
     let frame = FRAME_SAMPLES * CHANNELS;
     let mut ring: VecDeque<f32> = VecDeque::with_capacity(frame * 4);
+    let mut pcm = vec![0f32; frame]; // reusable encode scratch (one 20 ms frame)
     let mut out = vec![0u8; 4000]; // max Opus packet for a 20 ms frame fits easily
     let mut seq: u32 = 0;
     let mut sent: u64 = 0;
@@ -137,12 +202,19 @@ fn encode_loop(
 
     while !shutdown.load(Ordering::Relaxed) {
         match rx.recv_timeout(Duration::from_millis(100)) {
-            Ok(chunk) => ring.extend(chunk),
+            Ok(mut chunk) => {
+                // `drain(..)` keeps the Vec's capacity; hand the emptied buffer back to the
+                // callback's free-list (dropped only if the pool is momentarily full).
+                ring.extend(chunk.drain(..));
+                let _ = free_tx.try_send(chunk);
+            }
             Err(RecvTimeoutError::Timeout) => continue, // wake to re-check shutdown
             Err(RecvTimeoutError::Disconnected) => break,
         }
         while ring.len() >= frame {
-            let pcm: Vec<f32> = ring.drain(..frame).collect();
+            for (dst, src) in pcm.iter_mut().zip(ring.drain(..frame)) {
+                *dst = src;
+            }
             for &s in &pcm {
                 peak = peak.max(s.abs());
             }
@@ -157,8 +229,9 @@ fn encode_loop(
                     sent += 1;
                     if sent % 250 == 0 {
                         log::info!(
-                            "mic: sent={sent} captured_frames={} peak={peak:.3}",
+                            "mic: sent={sent} captured_frames={} dropped_chunks={} peak={peak:.3}",
                             captured.load(Ordering::Relaxed),
+                            dropped.load(Ordering::Relaxed),
                         );
                         peak = 0.0;
                     }
@@ -168,7 +241,8 @@ fn encode_loop(
         }
     }
     log::info!(
-        "mic: stopped (sent={sent} captured_frames={})",
+        "mic: stopped (sent={sent} captured_frames={} dropped_chunks={})",
         captured.load(Ordering::Relaxed),
+        dropped.load(Ordering::Relaxed),
     );
 }

clients/android/native/src/session.rs

@@ -1,762 +0,0 @@
-//! Session lifecycle + plane wiring over JNI.
-//!
-//! A connected session is a [`SessionHandle`] — an `Arc<NativeClient>` plus the decode thread it
-//! feeds — boxed and handed to Kotlin as an opaque `jlong`. The connector is `Sync`, so the decode
-//! thread pulls the video plane (`next_frame`) directly while Kotlin still holds the handle.
-//!
-//! Wired: connect/close, the video plane (HEVC `next_frame` → NDK AMediaCodec → the SurfaceView's
-//! `ANativeWindow`, see [`crate::decode`]), host→client audio ([`crate::audio`]), input
-//! (`send_input` — mouse/keyboard/gamepad), rumble/DualSense HID feedback ([`crate::feedback`]),
-//! and the trust surface: `nativeGenerateIdentity` (persistent identity, Keystore-wrapped on the
-//! Kotlin side), `nativeConnect` with identity + pin (TOFU / pinned), and `nativePair` (SPAKE2 PIN).
-//!
-//! TODO(M4 Android stage 1): client→host DualSense rich input (`send_rich_input`), mode
-//! renegotiation. Port the remaining orchestration from `clients/linux`.
-
-use jni::objects::{JObject, JString};
-use jni::sys::{jboolean, jdoubleArray, jint, jlong, jsize};
-use jni::JNIEnv;
-use punktfunk_core::client::NativeClient;
-use punktfunk_core::config::{CompositorPref, GamepadPref, Mode};
-use punktfunk_core::input::{InputEvent, InputKind};
-use std::panic::AssertUnwindSafe;
-use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::{Arc, Mutex};
-use std::thread::JoinHandle;
-use std::time::Duration;
-
-/// Run a JNI body, catching any panic at the FFI boundary and returning `default` instead.
-///
-/// A panic unwinding out of an `extern "system"` function aborts the whole process on Rust ≥ 1.81 —
-/// a hard crash of the embedding Android app with no logcat trace. This mirrors the discipline the C
-/// ABI already enforces (`punktfunk_core::abi` wraps every entry point in `catch_unwind`); the
-/// `panic = "unwind"` profile in the workspace `Cargo.toml` exists precisely so these guards work.
-/// We apply it to the teardown + background-thread shims (the "leaving a stream" path), where an
-/// unexpected panic (e.g. a poisoned `Mutex` during concurrent teardown) must degrade to a logged
-/// no-op rather than kill the app.
-pub(crate) fn jni_guard<T>(default: T, f: impl FnOnce() -> T) -> T {
-    std::panic::catch_unwind(AssertUnwindSafe(f)).unwrap_or_else(|_| {
-        log::error!("punktfunk JNI: caught a panic at the FFI boundary (returning default)");
-        default
-    })
-}
-
-/// A live session behind the `jlong` handle: the connector + the decode thread it feeds.
-pub(crate) struct SessionHandle {
-    // Read only by the android decode path (`nativeStartVideo` → `crate::decode`); on the host
-    // build (CI's workspace clippy/build) those readers are cfg'd out, so it's intentionally unused.
-    #[cfg_attr(not(target_os = "android"), allow(dead_code))]
-    pub client: Arc<NativeClient>,
-    video: Mutex<Option<VideoThread>>,
-    #[cfg(target_os = "android")]
-    audio: Mutex<Option<crate::audio::AudioPlayback>>,
-    #[cfg(target_os = "android")]
-    mic: Mutex<Option<crate::mic::MicCapture>>,
-}
-
-struct VideoThread {
-    shutdown: Arc<AtomicBool>,
-    join: Option<JoinHandle<()>>,
-    /// Live decode stats, written by the decode thread and drained ~1 Hz by `nativeVideoStats`.
-    stats: Arc<crate::stats::VideoStats>,
-}
-
-impl SessionHandle {
-    /// Signal the decode thread to stop and join it. Idempotent.
-    fn stop_video(&self) {
-        if let Some(mut vt) = self.video.lock().unwrap().take() {
-            vt.shutdown.store(true, Ordering::SeqCst);
-            if let Some(j) = vt.join.take() {
-                let _ = j.join();
-            }
-        }
-    }
-
-    /// Stop + close audio playback. Dropping the [`crate::audio::AudioPlayback`] joins its decode
-    /// thread and closes the AAudio stream. Idempotent.
-    #[cfg(target_os = "android")]
-    fn stop_audio(&self) {
-        let _ = self.audio.lock().unwrap().take();
-    }
-
-    /// Stop mic uplink. Dropping the [`crate::mic::MicCapture`] joins its encode thread and closes
-    /// the AAudio input stream. Idempotent.
-    #[cfg(target_os = "android")]
-    fn stop_mic(&self) {
-        let _ = self.mic.lock().unwrap().take();
-    }
-}
-
-impl Drop for SessionHandle {
-    fn drop(&mut self) {
-        self.stop_video();
-        #[cfg(target_os = "android")]
-        self.stop_audio();
-        #[cfg(target_os = "android")]
-        self.stop_mic();
-    }
-}
-
-/// SHA-256 fingerprint → 64 lowercase hex chars (matches the host log + client-rs).
-fn hex32(fp: &[u8; 32]) -> String {
-    use std::fmt::Write;
-    fp.iter().fold(String::with_capacity(64), |mut s, b| {
-        let _ = write!(s, "{b:02x}");
-        s
-    })
-}
-
-/// 64-hex → [u8; 32]; `None` on bad length/char.
-fn parse_hex32(s: &str) -> Option<[u8; 32]> {
-    if s.len() != 64 {
-        return None;
-    }
-    let mut out = [0u8; 32];
-    for (i, b) in out.iter_mut().enumerate() {
-        *b = u8::from_str_radix(&s[2 * i..2 * i + 2], 16).ok()?;
-    }
-    Some(out)
-}
-
-/// `NativeBridge.nativeGenerateIdentity(): String` — mint a fresh persistent self-signed identity.
-/// Returns `"<certPem>\n-----PUNKTFUNK-KEY-----\n<keyPem>"`, or `""` on failure (logged). Kotlin
-/// persists it (Keystore-wrapped) and only calls this again when the store is genuinely empty.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeGenerateIdentity<'local>(
-    env: JNIEnv<'local>,
-    _this: JObject<'local>,
-) -> jni::sys::jstring {
-    let out = match punktfunk_core::quic::endpoint::generate_identity() {
-        Ok((cert, key)) => format!("{cert}\n-----PUNKTFUNK-KEY-----\n{key}"),
-        Err(e) => {
-            log::error!("nativeGenerateIdentity failed: {e}");
-            String::new()
-        }
-    };
-    match env.new_string(out) {
-        Ok(s) => s.into_raw(),
-        Err(_) => JObject::null().into_raw(),
-    }
-}
-
-/// `NativeBridge.nativeConnect(host, port, w, h, hz, certPem, keyPem, pinHex, bitrateKbps,
-/// compositorPref, gamepadPref, hdrEnabled, audioChannels, timeoutMs): Long`. `certPem`/`keyPem`
-/// empty = anonymous, else presented as the persistent identity. `pinHex` empty = TOFU (read
-/// `nativeHostFingerprint` after), else 64-hex SHA-256 to pin the host (mismatch → 0). `bitrateKbps`
-/// 0 = host default. `compositorPref`/`gamepadPref` are `CompositorPref`/`GamepadPref` wire bytes
-/// (0 = Auto; unknown → Auto). `audioChannels` is the requested surround layout (2/6/8; normalized,
-/// anything else → stereo) — the host clamps it and the resolved count drives playback. `timeoutMs`
-/// is the handshake budget: the normal path passes a short value, the no-PIN "request access" path a
-/// long one (≥ the host's approval-park window) so a slow operator approval lands on this same parked
-/// connection rather than timing the client out first. Returns an opaque handle, or 0 on failure.
-#[no_mangle]
-#[allow(clippy::too_many_arguments)]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeConnect<'local>(
-    mut env: JNIEnv<'local>,
-    _this: JObject<'local>,
-    host: JString<'local>,
-    port: jint,
-    width: jint,
-    height: jint,
-    refresh_hz: jint,
-    cert_pem: JString<'local>,
-    key_pem: JString<'local>,
-    pin_hex: JString<'local>,
-    bitrate_kbps: jint,
-    compositor_pref: jint,
-    gamepad_pref: jint,
-    hdr_enabled: jboolean,
-    audio_channels: jint,
-    preferred_codec: jint,
-    timeout_ms: jint,
-) -> jlong {
-    let host: String = match env.get_string(&host) {
-        Ok(s) => s.into(),
-        Err(_) => return 0,
-    };
-    let cert: String = env
-        .get_string(&cert_pem)
-        .map(Into::into)
-        .unwrap_or_default();
-    let key: String = env.get_string(&key_pem).map(Into::into).unwrap_or_default();
-    let pin_hex: String = env.get_string(&pin_hex).map(Into::into).unwrap_or_default();
-
-    let identity: Option<(String, String)> = if cert.is_empty() || key.is_empty() {
-        None
-    } else {
-        Some((cert, key))
-    };
-    let pin: Option<[u8; 32]> = if pin_hex.is_empty() {
-        None
-    } else {
-        match parse_hex32(&pin_hex) {
-            Some(fp) => Some(fp),
-            None => {
-                log::error!("nativeConnect: bad pin hex (len {})", pin_hex.len());
-                return 0;
-            }
-        }
-    };
-    let mode = Mode {
-        width: width as u32,
-        height: height as u32,
-        refresh_hz: refresh_hz as u32,
-    };
-    match NativeClient::connect(
-        &host,
-        port as u16,
-        mode,
-        CompositorPref::from_u8(compositor_pref.clamp(0, u8::MAX as jint) as u8),
-        GamepadPref::from_u8(gamepad_pref.clamp(0, u8::MAX as jint) as u8),
-        bitrate_kbps.max(0) as u32, // 0 = host default
-        // Advertise 10-bit + HDR ONLY when this device's display can actually present it (Kotlin
-        // checks Display.getHdrCapabilities() and passes the result): the host (e.g. Windows) then
-        // upgrades to a Main10 / BT.2020 PQ encode. On an SDR display we advertise 0 so the host
-        // sends a proper 8-bit BT.709 stream rather than PQ the panel would mis-tone-map. AMediaCodec
-        // decodes Main10 from the SPS and the decode loop signals the Surface HDR dataspace + static
-        // metadata (see crate::decode).
-        if hdr_enabled != 0 {
-            punktfunk_core::quic::VIDEO_CAP_10BIT | punktfunk_core::quic::VIDEO_CAP_HDR
-        } else {
-            0
-        },
-        // Requested surround layout (2 = stereo / 6 = 5.1 / 8 = 7.1). The host clamps to what it can
-        // capture and echoes the resolved count in `connector.audio_channels`, which drives the
-        // decoder + AAudio layout (read in `crate::audio::AudioPlayback::start`). Anything else
-        // normalizes to stereo here.
-        punktfunk_core::audio::normalize_channels(audio_channels.clamp(0, u8::MAX as jint) as u8),
-        // Codecs this device can decode — AMediaCodec decodes both HEVC and H.264 (AV1 isn't wired;
-        // hosts don't emit it on the native path yet). The host resolves the emitted codec from these
-        // + the soft `preferred_codec` and echoes it in `connector.codec`, which drives the mime below.
-        punktfunk_core::quic::CODEC_H264 | punktfunk_core::quic::CODEC_HEVC,
-        preferred_codec.clamp(0, u8::MAX as jint) as u8,
-        None,     // launch: default app
-        pin,      // Some → Crypto on host-fp mismatch
-        identity, // owned (cert, key) PEM, or None (anonymous)
-        // Handshake budget from Kotlin: ~10 s for a normal connect, ~185 s for "request access"
-        // (the host parks the connection until the operator approves the device — see ConnectScreen).
-        Duration::from_millis(timeout_ms.max(0) as u64),
-    ) {
-        Ok(client) => {
-            let handle = SessionHandle {
-                client: Arc::new(client),
-                video: Mutex::new(None),
-                #[cfg(target_os = "android")]
-                audio: Mutex::new(None),
-                #[cfg(target_os = "android")]
-                mic: Mutex::new(None),
-            };
-            Box::into_raw(Box::new(handle)) as jlong
-        }
-        Err(e) => {
-            log::error!("nativeConnect to {host}:{port} failed: {e}");
-            0
-        }
-    }
-}
-
-/// `NativeBridge.nativeClose(handle)` — drop the session (stops the decode thread, then RAII-tears
-/// down the connector). No-op on `0`.
-///
-/// # Safety contract
-/// `handle` must be `0` or a live handle from [`Java_io_unom_punktfunk_kit_NativeBridge_nativeConnect`],
-/// closed exactly once and not concurrently with other calls on the same handle (Kotlin owns this).
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeClose(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-) {
-    jni_guard((), || {
-        if handle != 0 {
-            // SAFETY: per the contract, `handle` is a live `Box<SessionHandle>` pointer.
-            unsafe { drop(Box::from_raw(handle as *mut SessionHandle)) };
-        }
-    })
-}
-
-/// `NativeBridge.nativeHostFingerprint(handle): String` — the SHA-256 (64-hex) of the cert the host
-/// presented on this connection. Valid after a successful `nativeConnect`; Kotlin pins it on a TOFU
-/// connect. `""` on a `0` handle.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeHostFingerprint<'local>(
-    env: JNIEnv<'local>,
-    _this: JObject<'local>,
-    handle: jlong,
-) -> jni::sys::jstring {
-    let out = if handle == 0 {
-        String::new()
-    } else {
-        // SAFETY: live handle per the nativeConnect/nativeClose contract.
-        let h = unsafe { &*(handle as *const SessionHandle) };
-        hex32(&h.client.host_fingerprint)
-    };
-    match env.new_string(out) {
-        Ok(s) => s.into_raw(),
-        Err(_) => JObject::null().into_raw(),
-    }
-}
-
-/// `NativeBridge.nativePair(host, port, certPem, keyPem, pin, name): String` — run the SPAKE2 PIN
-/// ceremony, presenting our persistent identity. On success returns the host's verified fingerprint
-/// (64-hex) to persist + pin; on any failure (wrong PIN / MITM / host reject / unreachable) returns
-/// `""` (logged). Blocking — Kotlin calls it off the UI thread.
-#[no_mangle]
-#[allow(clippy::too_many_arguments)]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativePair<'local>(
-    mut env: JNIEnv<'local>,
-    _this: JObject<'local>,
-    host: JString<'local>,
-    port: jint,
-    cert_pem: JString<'local>,
-    key_pem: JString<'local>,
-    pin: JString<'local>,
-    name: JString<'local>,
-) -> jni::sys::jstring {
-    let g = |e: &mut JNIEnv<'local>, j: &JString<'local>| -> String {
-        e.get_string(j).map(Into::into).unwrap_or_default()
-    };
-    let host = g(&mut env, &host);
-    let cert = g(&mut env, &cert_pem);
-    let key = g(&mut env, &key_pem);
-    let pin = g(&mut env, &pin);
-    let name = g(&mut env, &name);
-
-    let out = if host.is_empty() || cert.is_empty() || key.is_empty() {
-        log::error!("nativePair: missing host/identity");
-        String::new()
-    } else {
-        match NativeClient::pair(
-            &host,
-            port as u16,
-            (&cert, &key), // borrowed identity
-            &pin,
-            &name,
-            Duration::from_secs(60),
-        ) {
-            Ok(host_fp) => hex32(&host_fp),
-            Err(e) => {
-                // Crypto error == wrong PIN / MITM; anything else == transport/host reject.
-                log::error!("nativePair to {host}:{port} failed: {e}");
-                String::new()
-            }
-        }
-    };
-    match env.new_string(out) {
-        Ok(s) => s.into_raw(),
-        Err(_) => JObject::null().into_raw(),
-    }
-}
-
-/// `NativeBridge.nativeStartVideo(handle, surface)` — wrap the SurfaceView's `Surface` as an
-/// `ANativeWindow` and start the HEVC decode thread rendering onto it. No-op if already started.
-#[cfg(target_os = "android")]
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStartVideo(
-    env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    surface: JObject,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the nativeConnect/nativeClose contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let mut guard = h.video.lock().unwrap();
-    if guard.is_some() {
-        return; // already streaming
-    }
-    // SAFETY: `env`/`surface` are valid JNI pointers for this call. `as *mut _` bridges any
-    // jni-sys version skew between the `jni` and `ndk` crates (both are raw `*mut _` pointers).
-    let window = match unsafe {
-        ndk::native_window::NativeWindow::from_surface(
-            env.get_native_interface() as *mut _,
-            surface.as_raw() as *mut _,
-        )
-    } {
-        Some(w) => w,
-        None => {
-            log::error!("nativeStartVideo: no ANativeWindow from Surface");
-            return;
-        }
-    };
-    let shutdown = Arc::new(AtomicBool::new(false));
-    let stats = Arc::new(crate::stats::VideoStats::new());
-    let client = h.client.clone();
-    let sd = shutdown.clone();
-    let st = stats.clone();
-    let join = std::thread::Builder::new()
-        .name("pf-decode".into())
-        .spawn(move || crate::decode::run(client, window, sd, st))
-        .ok();
-    *guard = Some(VideoThread {
-        shutdown,
-        join,
-        stats,
-    });
-}
-
-/// `NativeBridge.nativeStopVideo(handle)` — stop + join the decode thread (without closing the
-/// session). No-op on `0`.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopVideo(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-) {
-    jni_guard((), || {
-        if handle != 0 {
-            // SAFETY: live handle per the contract.
-            let h = unsafe { &*(handle as *const SessionHandle) };
-            h.stop_video();
-        }
-    })
-}
-
-/// `NativeBridge.nativeVideoStats(handle): DoubleArray?` — drain ~1 s of decode stats for the HUD.
-/// Returns 14 doubles
-/// `[fps, mbps, latP50Ms, latP95Ms, latValid, skewCorrected, width, height, refreshHz, framesDropped,
-/// bitDepth, colorPrimaries, colorTransfer, chromaFormatIdc]`
-/// (the two flags are 1.0/0.0; the trailing four describe the negotiated video feed — see below), or
-/// `null` when no decode thread is running. Poll ~1 Hz from the UI; each call resets the measurement
-/// window. Not android-gated — pure `jni` + connector reads, so it links on the host build too
-/// (Kotlin only ever calls it on device).
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeVideoStats(
-    env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-) -> jdoubleArray {
-    jni_guard(std::ptr::null_mut(), || {
-        if handle == 0 {
-            return std::ptr::null_mut();
-        }
-        // SAFETY: live handle per the nativeConnect/nativeClose contract.
-        let h = unsafe { &*(handle as *const SessionHandle) };
-        let snap = match h.video.lock().unwrap().as_ref() {
-            Some(vt) => vt.stats.drain(),
-            None => return std::ptr::null_mut(), // not streaming → no stats
-        };
-        let mode = h.client.mode();
-        let color = h.client.color;
-        let buf: [f64; 14] = [
-            snap.fps,
-            snap.mbps,
-            snap.lat_p50_ms,
-            snap.lat_p95_ms,
-            if snap.lat_valid { 1.0 } else { 0.0 },
-            if snap.skew_corrected { 1.0 } else { 0.0 },
-            mode.width as f64,
-            mode.height as f64,
-            mode.refresh_hz as f64,
-            h.client.frames_dropped() as f64,
-            // Video-feed properties the host resolved at the handshake (Welcome): encode bit depth
-            // (8 / 10), the CICP colour primaries + transfer code points (Kotlin maps these to a
-            // colour-space / HDR label — transfer 16 = PQ, 18 = HLG ⇒ HDR), and the HEVC
-            // chroma_format_idc (1 = 4:2:0, 3 = 4:4:4). Static for the session unless renegotiated.
-            h.client.bit_depth as f64,
-            color.primaries as f64,
-            color.transfer as f64,
-            h.client.chroma_format as f64,
-        ];
-        let arr = match env.new_double_array(buf.len() as jsize) {
-            Ok(a) => a,
-            Err(_) => return std::ptr::null_mut(),
-        };
-        if env.set_double_array_region(&arr, 0, &buf).is_err() {
-            return std::ptr::null_mut();
-        }
-        arr.into_raw()
-    })
-}
-
-/// `NativeBridge.nativeStartAudio(handle)` — start the Opus→AAudio playback thread. No-op if already
-/// started or on a `0` handle. Best-effort: a failure leaves video streaming.
-#[cfg(target_os = "android")]
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStartAudio(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the nativeConnect/nativeClose contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let mut guard = h.audio.lock().unwrap();
-    if guard.is_some() {
-        return; // already playing
-    }
-    match crate::audio::AudioPlayback::start(h.client.clone()) {
-        Some(p) => *guard = Some(p),
-        None => log::error!("nativeStartAudio: playback init failed (video unaffected)"),
-    }
-}
-
-/// `NativeBridge.nativeStopAudio(handle)` — stop + join the audio thread and close AAudio (without
-/// closing the session). No-op on `0`.
-#[cfg(target_os = "android")]
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopAudio(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-) {
-    jni_guard((), || {
-        if handle != 0 {
-            // SAFETY: live handle per the contract.
-            let h = unsafe { &*(handle as *const SessionHandle) };
-            h.stop_audio();
-        }
-    })
-}
-
-/// `NativeBridge.nativeStartMic(handle)` — start mic capture (AAudio input → Opus → host `send_mic`).
-/// No-op if already running or on a `0` handle. Caller MUST hold RECORD_AUDIO; a failure (e.g. no
-/// permission) leaves the rest of the session streaming.
-#[cfg(target_os = "android")]
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStartMic(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the nativeConnect/nativeClose contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let mut guard = h.mic.lock().unwrap();
-    if guard.is_some() {
-        return; // already capturing
-    }
-    match crate::mic::MicCapture::start(h.client.clone()) {
-        Some(m) => *guard = Some(m),
-        None => log::error!("nativeStartMic: mic init failed (RECORD_AUDIO? — session unaffected)"),
-    }
-}
-
-/// `NativeBridge.nativeStopMic(handle)` — stop + join the mic thread and close the AAudio input
-/// stream (without closing the session). No-op on `0`.
-#[cfg(target_os = "android")]
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopMic(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-) {
-    jni_guard((), || {
-        if handle != 0 {
-            // SAFETY: live handle per the contract.
-            let h = unsafe { &*(handle as *const SessionHandle) };
-            h.stop_mic();
-        }
-    })
-}
-
-// ---- Input plane: Kotlin capture → NativeClient::send_input ----------------------------------
-// All four are `&self` on the `Sync` connector (send_input is a non-blocking datagram push), safe
-// from the Kotlin UI thread. NOT android-gated — send_input exists on the host build too, so these
-// compile everywhere (parity with nativeConnect/nativeClose). The wire codes are the GameStream
-// conventions: buttons 1=left/2=middle/3=right/4=X1/5=X2; scroll axis 0=vertical/1=horizontal,
-// signed 120-unit delta, +=up/right; keys are Windows VK (mapped from KEYCODE_* on the Kotlin side).
-
-/// `NativeBridge.nativeSendPointerMove(handle, dx, dy)` — relative mouse motion (screen +y down).
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendPointerMove(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    dx: jint,
-    dy: jint,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the nativeConnect/nativeClose contract; send_input is &self.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let _ = h.client.send_input(&InputEvent {
-        kind: InputKind::MouseMove,
-        _pad: [0; 3],
-        code: 0,
-        x: dx,
-        y: dy,
-        flags: 0,
-    });
-}
-
-/// `NativeBridge.nativeSendPointerAbs(handle, x, y, surfaceWidth, surfaceHeight)` — absolute cursor
-/// position: the host moves the pointer to `x`/`y` in a `surfaceWidth`×`surfaceHeight` pixel space,
-/// normalizing against the size packed into `flags` as `(w << 16) | h` and mapping into the output
-/// region (it drops the event if that size is zero). This is the touch "direct pointing" path — the
-/// cursor jumps to the finger — and matches the Apple client's absolute touch forwarding.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendPointerAbs(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    x: jint,
-    y: jint,
-    surface_width: jint,
-    surface_height: jint,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let w = (surface_width.max(0) as u32) & 0xffff;
-    let ht = (surface_height.max(0) as u32) & 0xffff;
-    let _ = h.client.send_input(&InputEvent {
-        kind: InputKind::MouseMoveAbs,
-        _pad: [0; 3],
-        code: 0,
-        x,
-        y,
-        flags: (w << 16) | ht,
-    });
-}
-
-/// `NativeBridge.nativeSendPointerButton(handle, button, down)` — one button transition.
-/// `button`: GameStream id (1=left, 2=middle, 3=right, 4=X1, 5=X2). `down`: 1=press, 0=release.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendPointerButton(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    button: jint,
-    down: jboolean,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let _ = h.client.send_input(&InputEvent {
-        kind: if down != 0 {
-            InputKind::MouseButtonDown
-        } else {
-            InputKind::MouseButtonUp
-        },
-        _pad: [0; 3],
-        code: button as u32,
-        x: 0,
-        y: 0,
-        flags: 0,
-    });
-}
-
-/// `NativeBridge.nativeSendScroll(handle, axis, delta)` — one scroll step. `axis`: 0=vertical,
-/// 1=horizontal. `delta`: signed, WHEEL_DELTA(120)-scaled, +=up/right.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendScroll(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    axis: jint,
-    delta: jint,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let _ = h.client.send_input(&InputEvent {
-        kind: InputKind::MouseScroll,
-        _pad: [0; 3],
-        code: axis as u32,
-        x: delta,
-        y: 0,
-        flags: 0,
-    });
-}
-
-/// `NativeBridge.nativeSendKey(handle, vk, down, mods)` — one key transition. `vk`: Windows
-/// Virtual-Key code (0 = unmapped → dropped). `down`: 1=press, 0=release. `mods`: VK modifier
-/// bitmask (0 for now — the host folds modifiers from the L/R modifier key events themselves).
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendKey(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    vk: jint,
-    down: jboolean,
-    mods: jint,
-) {
-    if handle == 0 || vk == 0 {
-        return;
-    }
-    // SAFETY: live handle per the contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let _ = h.client.send_input(&InputEvent {
-        kind: if down != 0 {
-            InputKind::KeyDown
-        } else {
-            InputKind::KeyUp
-        },
-        _pad: [0; 3],
-        code: vk as u32,
-        x: 0,
-        y: 0,
-        flags: mods as u32,
-    });
-}
-
-// ---- Gamepad: Kotlin captures (KeyEvent/MotionEvent) → NativeClient::send_input ---------------
-// Single-pad model: exactly one controller, forwarded as pad 0 (flags = 0). Buttons carry the
-// gamepad::BTN_* bit in `code` and pressed/released in `x` (1/0); axes carry the gamepad::AXIS_* id
-// in `code` and the value in `x` (sticks i16 −32768..32767, +y = up; triggers 0..255). The host
-// accumulates the incremental events into its virtual xpad. Wire contract: input.rs::gamepad.
-
-/// `NativeBridge.nativeSendGamepadButton(handle, bit, down)` — one gamepad button transition.
-/// `bit`: a `gamepad::BTN_*` bit (e.g. BTN_A = 0x1000). `down`: 1=press, 0=release.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendGamepadButton(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    bit: jint,
-    down: jboolean,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let _ = h.client.send_input(&InputEvent {
-        kind: InputKind::GamepadButton,
-        _pad: [0; 3],
-        code: bit as u32,
-        x: i32::from(down != 0),
-        y: 0,
-        flags: 0, // pad index 0 — single-pad model
-    });
-}
-
-/// `NativeBridge.nativeSendGamepadAxis(handle, axisId, value)` — one gamepad axis update.
-/// `axisId`: a `gamepad::AXIS_*` id (LS_X=0..RT=5). `value`: stick i16 (−32768..32767, +y=up) or
-/// trigger 0..255.
-#[no_mangle]
-pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendGamepadAxis(
-    _env: JNIEnv,
-    _this: JObject,
-    handle: jlong,
-    axis_id: jint,
-    value: jint,
-) {
-    if handle == 0 {
-        return;
-    }
-    // SAFETY: live handle per the contract.
-    let h = unsafe { &*(handle as *const SessionHandle) };
-    let _ = h.client.send_input(&InputEvent {
-        kind: InputKind::GamepadAxis,
-        _pad: [0; 3],
-        code: axis_id as u32,
-        x: value,
-        y: 0,
-        flags: 0, // pad index 0 — single-pad model
-    });
-}

clients/android/native/src/session/connect.rs

@@ -0,0 +1,244 @@
+//! Connect lifecycle + the trust surface: identity mint, connect (TOFU / pinned), close,
+//! host-fingerprint read, and the SPAKE2 PIN pairing ceremony.
+
+use jni::objects::{JObject, JString};
+use jni::sys::{jboolean, jint, jlong};
+use jni::JNIEnv;
+use punktfunk_core::client::NativeClient;
+use punktfunk_core::config::{CompositorPref, GamepadPref, Mode};
+use std::sync::{Arc, Mutex};
+use std::time::Duration;
+
+use super::{hex32, jni_guard, parse_hex32, SessionHandle};
+
+/// `NativeBridge.nativeGenerateIdentity(): String` — mint a fresh persistent self-signed identity.
+/// Returns `"<certPem>\n-----PUNKTFUNK-KEY-----\n<keyPem>"`, or `""` on failure (logged). Kotlin
+/// persists it (Keystore-wrapped) and only calls this again when the store is genuinely empty.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeGenerateIdentity<'local>(
+    env: JNIEnv<'local>,
+    _this: JObject<'local>,
+) -> jni::sys::jstring {
+    let out = match punktfunk_core::quic::endpoint::generate_identity() {
+        Ok((cert, key)) => format!("{cert}\n-----PUNKTFUNK-KEY-----\n{key}"),
+        Err(e) => {
+            log::error!("nativeGenerateIdentity failed: {e}");
+            String::new()
+        }
+    };
+    match env.new_string(out) {
+        Ok(s) => s.into_raw(),
+        Err(_) => JObject::null().into_raw(),
+    }
+}
+
+/// `NativeBridge.nativeConnect(host, port, w, h, hz, certPem, keyPem, pinHex, bitrateKbps,
+/// compositorPref, gamepadPref, hdrEnabled, audioChannels, preferredCodec, timeoutMs): Long`.
+/// `certPem`/`keyPem` empty = anonymous, else presented as the persistent identity. `pinHex` empty
+/// = TOFU (read `nativeHostFingerprint` after), else 64-hex SHA-256 to pin the host (mismatch → 0).
+/// `bitrateKbps` 0 = host default. `compositorPref`/`gamepadPref` are `CompositorPref`/`GamepadPref`
+/// wire bytes (0 = Auto; unknown → Auto). `audioChannels` is the requested surround layout (2/6/8;
+/// normalized, anything else → stereo) — the host clamps it and the resolved count drives playback.
+/// `preferredCodec` is the soft codec preference wire byte (0 = Auto). `timeoutMs` is the handshake
+/// budget: the normal path passes a short value, the no-PIN "request access" path a long one (≥ the
+/// host's approval-park window) so a slow operator approval lands on this same parked connection
+/// rather than timing the client out first. Returns an opaque handle, or 0 on failure.
+#[no_mangle]
+#[allow(clippy::too_many_arguments)]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeConnect<'local>(
+    mut env: JNIEnv<'local>,
+    _this: JObject<'local>,
+    host: JString<'local>,
+    port: jint,
+    width: jint,
+    height: jint,
+    refresh_hz: jint,
+    cert_pem: JString<'local>,
+    key_pem: JString<'local>,
+    pin_hex: JString<'local>,
+    bitrate_kbps: jint,
+    compositor_pref: jint,
+    gamepad_pref: jint,
+    hdr_enabled: jboolean,
+    audio_channels: jint,
+    preferred_codec: jint,
+    timeout_ms: jint,
+) -> jlong {
+    let host: String = match env.get_string(&host) {
+        Ok(s) => s.into(),
+        Err(_) => return 0,
+    };
+    let cert: String = env
+        .get_string(&cert_pem)
+        .map(Into::into)
+        .unwrap_or_default();
+    let key: String = env.get_string(&key_pem).map(Into::into).unwrap_or_default();
+    let pin_hex: String = env.get_string(&pin_hex).map(Into::into).unwrap_or_default();
+
+    let identity: Option<(String, String)> = if cert.is_empty() || key.is_empty() {
+        None
+    } else {
+        Some((cert, key))
+    };
+    let pin: Option<[u8; 32]> = if pin_hex.is_empty() {
+        None
+    } else {
+        match parse_hex32(&pin_hex) {
+            Some(fp) => Some(fp),
+            None => {
+                log::error!("nativeConnect: bad pin hex (len {})", pin_hex.len());
+                return 0;
+            }
+        }
+    };
+    let mode = Mode {
+        width: width as u32,
+        height: height as u32,
+        refresh_hz: refresh_hz as u32,
+    };
+    match NativeClient::connect(
+        &host,
+        port as u16,
+        mode,
+        CompositorPref::from_u8(compositor_pref.clamp(0, u8::MAX as jint) as u8),
+        GamepadPref::from_u8(gamepad_pref.clamp(0, u8::MAX as jint) as u8),
+        bitrate_kbps.max(0) as u32, // 0 = host default
+        // Advertise 10-bit + HDR ONLY when this device's display can actually present it (Kotlin
+        // checks Display.getHdrCapabilities() and passes the result): the host (e.g. Windows) then
+        // upgrades to a Main10 / BT.2020 PQ encode. On an SDR display we advertise 0 so the host
+        // sends a proper 8-bit BT.709 stream rather than PQ the panel would mis-tone-map. AMediaCodec
+        // decodes Main10 from the SPS and the decode loop signals the Surface HDR dataspace + static
+        // metadata (see crate::decode).
+        if hdr_enabled != 0 {
+            punktfunk_core::quic::VIDEO_CAP_10BIT | punktfunk_core::quic::VIDEO_CAP_HDR
+        } else {
+            0
+        },
+        // Requested surround layout (2 = stereo / 6 = 5.1 / 8 = 7.1). The host clamps to what it can
+        // capture and echoes the resolved count in `connector.audio_channels`, which drives the
+        // decoder + AAudio layout (read in `crate::audio::AudioPlayback::start`). Anything else
+        // normalizes to stereo here.
+        punktfunk_core::audio::normalize_channels(audio_channels.clamp(0, u8::MAX as jint) as u8),
+        // Codecs this device can decode — AMediaCodec decodes both HEVC and H.264 (AV1 isn't wired;
+        // hosts don't emit it on the native path yet). The host resolves the emitted codec from these
+        // + the soft `preferred_codec` and echoes it in `connector.codec`, which drives the mime below.
+        punktfunk_core::quic::CODEC_H264 | punktfunk_core::quic::CODEC_HEVC,
+        preferred_codec.clamp(0, u8::MAX as jint) as u8,
+        None,     // launch: default app
+        pin,      // Some → Crypto on host-fp mismatch
+        identity, // owned (cert, key) PEM, or None (anonymous)
+        // Handshake budget from Kotlin: ~10 s for a normal connect, ~185 s for "request access"
+        // (the host parks the connection until the operator approves the device — see ConnectScreen).
+        Duration::from_millis(timeout_ms.max(0) as u64),
+    ) {
+        Ok(client) => {
+            let handle = SessionHandle {
+                client: Arc::new(client),
+                stats: Arc::new(crate::stats::VideoStats::new()),
+                video: Mutex::new(None),
+                #[cfg(target_os = "android")]
+                audio: Mutex::new(None),
+                #[cfg(target_os = "android")]
+                mic: Mutex::new(None),
+            };
+            Box::into_raw(Box::new(handle)) as jlong
+        }
+        Err(e) => {
+            log::error!("nativeConnect to {host}:{port} failed: {e}");
+            0
+        }
+    }
+}
+
+/// `NativeBridge.nativeClose(handle)` — drop the session (stops the decode thread, then RAII-tears
+/// down the connector). No-op on `0`.
+///
+/// # Safety contract
+/// `handle` must be `0` or a live handle from [`Java_io_unom_punktfunk_kit_NativeBridge_nativeConnect`],
+/// closed exactly once and not concurrently with other calls on the same handle (Kotlin owns this).
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeClose(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+) {
+    jni_guard((), || {
+        if handle != 0 {
+            // SAFETY: per the contract, `handle` is a live `Box<SessionHandle>` pointer.
+            unsafe { drop(Box::from_raw(handle as *mut SessionHandle)) };
+        }
+    })
+}
+
+/// `NativeBridge.nativeHostFingerprint(handle): String` — the SHA-256 (64-hex) of the cert the host
+/// presented on this connection. Valid after a successful `nativeConnect`; Kotlin pins it on a TOFU
+/// connect. `""` on a `0` handle.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeHostFingerprint<'local>(
+    env: JNIEnv<'local>,
+    _this: JObject<'local>,
+    handle: jlong,
+) -> jni::sys::jstring {
+    let out = if handle == 0 {
+        String::new()
+    } else {
+        // SAFETY: live handle per the nativeConnect/nativeClose contract.
+        let h = unsafe { &*(handle as *const SessionHandle) };
+        hex32(&h.client.host_fingerprint)
+    };
+    match env.new_string(out) {
+        Ok(s) => s.into_raw(),
+        Err(_) => JObject::null().into_raw(),
+    }
+}
+
+/// `NativeBridge.nativePair(host, port, certPem, keyPem, pin, name): String` — run the SPAKE2 PIN
+/// ceremony, presenting our persistent identity. On success returns the host's verified fingerprint
+/// (64-hex) to persist + pin; on any failure (wrong PIN / MITM / host reject / unreachable) returns
+/// `""` (logged). Blocking — Kotlin calls it off the UI thread.
+#[no_mangle]
+#[allow(clippy::too_many_arguments)]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativePair<'local>(
+    mut env: JNIEnv<'local>,
+    _this: JObject<'local>,
+    host: JString<'local>,
+    port: jint,
+    cert_pem: JString<'local>,
+    key_pem: JString<'local>,
+    pin: JString<'local>,
+    name: JString<'local>,
+) -> jni::sys::jstring {
+    let g = |e: &mut JNIEnv<'local>, j: &JString<'local>| -> String {
+        e.get_string(j).map(Into::into).unwrap_or_default()
+    };
+    let host = g(&mut env, &host);
+    let cert = g(&mut env, &cert_pem);
+    let key = g(&mut env, &key_pem);
+    let pin = g(&mut env, &pin);
+    let name = g(&mut env, &name);
+
+    let out = if host.is_empty() || cert.is_empty() || key.is_empty() {
+        log::error!("nativePair: missing host/identity");
+        String::new()
+    } else {
+        match NativeClient::pair(
+            &host,
+            port as u16,
+            (&cert, &key), // borrowed identity
+            &pin,
+            &name,
+            Duration::from_secs(60),
+        ) {
+            Ok(host_fp) => hex32(&host_fp),
+            Err(e) => {
+                // Crypto error == wrong PIN / MITM; anything else == transport/host reject.
+                log::error!("nativePair to {host}:{port} failed: {e}");
+                String::new()
+            }
+        }
+    };
+    match env.new_string(out) {
+        Ok(s) => s.into_raw(),
+        Err(_) => JObject::null().into_raw(),
+    }
+}

clients/android/native/src/session/input.rs

@@ -0,0 +1,159 @@
+//! Input plane: Kotlin capture → `NativeClient::send_input`.
+//!
+//! All shims are `&self` on the `Sync` connector (send_input is a non-blocking datagram push), safe
+//! from the Kotlin UI thread. NOT android-gated — send_input exists on the host build too, so these
+//! compile everywhere (parity with nativeConnect/nativeClose). The wire codes are the GameStream
+//! conventions: buttons 1=left/2=middle/3=right/4=X1/5=X2; scroll axis 0=vertical/1=horizontal,
+//! signed 120-unit delta, +=up/right; keys are Windows VK (mapped from KEYCODE_* on the Kotlin side).
+
+use jni::objects::JObject;
+use jni::sys::{jboolean, jint, jlong};
+use jni::JNIEnv;
+use punktfunk_core::input::{InputEvent, InputKind};
+
+use super::SessionHandle;
+
+/// Shared shim body: guard against a `0` handle, deref, and push one [`InputEvent`].
+fn send_event(handle: jlong, kind: InputKind, code: u32, x: i32, y: i32, flags: u32) {
+    if handle == 0 {
+        return;
+    }
+    // SAFETY: live handle per the nativeConnect/nativeClose contract; send_input is &self.
+    let h = unsafe { &*(handle as *const SessionHandle) };
+    let _ = h.client.send_input(&InputEvent {
+        kind,
+        _pad: [0; 3],
+        code,
+        x,
+        y,
+        flags,
+    });
+}
+
+/// `NativeBridge.nativeSendPointerMove(handle, dx, dy)` — relative mouse motion (screen +y down).
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendPointerMove(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    dx: jint,
+    dy: jint,
+) {
+    send_event(handle, InputKind::MouseMove, 0, dx, dy, 0);
+}
+
+/// `NativeBridge.nativeSendPointerAbs(handle, x, y, surfaceWidth, surfaceHeight)` — absolute cursor
+/// position: the host moves the pointer to `x`/`y` in a `surfaceWidth`×`surfaceHeight` pixel space,
+/// normalizing against the size packed into `flags` as `(w << 16) | h` and mapping into the output
+/// region (it drops the event if that size is zero). This is the touch "direct pointing" path — the
+/// cursor jumps to the finger — and matches the Apple client's absolute touch forwarding.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendPointerAbs(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    x: jint,
+    y: jint,
+    surface_width: jint,
+    surface_height: jint,
+) {
+    let w = (surface_width.max(0) as u32) & 0xffff;
+    let ht = (surface_height.max(0) as u32) & 0xffff;
+    send_event(handle, InputKind::MouseMoveAbs, 0, x, y, (w << 16) | ht);
+}
+
+/// `NativeBridge.nativeSendPointerButton(handle, button, down)` — one button transition.
+/// `button`: GameStream id (1=left, 2=middle, 3=right, 4=X1, 5=X2). `down`: 1=press, 0=release.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendPointerButton(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    button: jint,
+    down: jboolean,
+) {
+    let kind = if down != 0 {
+        InputKind::MouseButtonDown
+    } else {
+        InputKind::MouseButtonUp
+    };
+    send_event(handle, kind, button as u32, 0, 0, 0);
+}
+
+/// `NativeBridge.nativeSendScroll(handle, axis, delta)` — one scroll step. `axis`: 0=vertical,
+/// 1=horizontal. `delta`: signed, WHEEL_DELTA(120)-scaled, +=up/right.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendScroll(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    axis: jint,
+    delta: jint,
+) {
+    send_event(handle, InputKind::MouseScroll, axis as u32, delta, 0, 0);
+}
+
+/// `NativeBridge.nativeSendKey(handle, vk, down, mods)` — one key transition. `vk`: Windows
+/// Virtual-Key code (0 = unmapped → dropped). `down`: 1=press, 0=release. `mods`: VK modifier
+/// bitmask (0 for now — the host folds modifiers from the L/R modifier key events themselves).
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendKey(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    vk: jint,
+    down: jboolean,
+    mods: jint,
+) {
+    if vk == 0 {
+        return;
+    }
+    let kind = if down != 0 {
+        InputKind::KeyDown
+    } else {
+        InputKind::KeyUp
+    };
+    send_event(handle, kind, vk as u32, 0, 0, mods as u32);
+}
+
+// ---- Gamepad: Kotlin captures (KeyEvent/MotionEvent) → NativeClient::send_input ---------------
+// Single-pad model: exactly one controller, forwarded as pad 0 (flags = 0). Buttons carry the
+// gamepad::BTN_* bit in `code` and pressed/released in `x` (1/0); axes carry the gamepad::AXIS_* id
+// in `code` and the value in `x` (sticks i16 −32768..32767, +y = up; triggers 0..255). The host
+// accumulates the incremental events into its virtual xpad. Wire contract: input.rs::gamepad.
+
+/// `NativeBridge.nativeSendGamepadButton(handle, bit, down)` — one gamepad button transition.
+/// `bit`: a `gamepad::BTN_*` bit (e.g. BTN_A = 0x1000). `down`: 1=press, 0=release.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendGamepadButton(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    bit: jint,
+    down: jboolean,
+) {
+    // flags = 0: pad index 0 — single-pad model.
+    send_event(
+        handle,
+        InputKind::GamepadButton,
+        bit as u32,
+        i32::from(down != 0),
+        0,
+        0,
+    );
+}
+
+/// `NativeBridge.nativeSendGamepadAxis(handle, axisId, value)` — one gamepad axis update.
+/// `axisId`: a `gamepad::AXIS_*` id (LS_X=0..RT=5). `value`: stick i16 (−32768..32767, +y=up) or
+/// trigger 0..255.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSendGamepadAxis(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    axis_id: jint,
+    value: jint,
+) {
+    // flags = 0: pad index 0 — single-pad model.
+    send_event(handle, InputKind::GamepadAxis, axis_id as u32, value, 0, 0);
+}

clients/android/native/src/session/mod.rs

@@ -0,0 +1,124 @@
+//! Session lifecycle + plane wiring over JNI.
+//!
+//! A connected session is a [`SessionHandle`] — an `Arc<NativeClient>` plus the decode thread it
+//! feeds — boxed and handed to Kotlin as an opaque `jlong`. The connector is `Sync`, so the decode
+//! thread pulls the video plane (`next_frame`) directly while Kotlin still holds the handle.
+//!
+//! Wired: connect/close, the video plane (HEVC `next_frame` → NDK AMediaCodec → the SurfaceView's
+//! `ANativeWindow`, see [`crate::decode`]), host→client audio ([`crate::audio`]), input
+//! (`send_input` — mouse/keyboard/gamepad), rumble/DualSense HID feedback ([`crate::feedback`]),
+//! and the trust surface: `nativeGenerateIdentity` (persistent identity, Keystore-wrapped on the
+//! Kotlin side), `nativeConnect` with identity + pin (TOFU / pinned), and `nativePair` (SPAKE2 PIN).
+//!
+//! Split by concern: [`connect`] (identity + connect/close + the trust surface), [`planes`]
+//! (video/audio/mic start/stop + the stats drain), [`input`] (the input-plane shims). This module
+//! keeps the shared infrastructure they all deref through.
+//!
+//! TODO(M4 Android stage 1): client→host DualSense rich input (`send_rich_input`), mode
+//! renegotiation. Port the remaining orchestration from `clients/linux`.
+
+mod connect;
+mod input;
+mod planes;
+
+use punktfunk_core::client::NativeClient;
+use std::panic::AssertUnwindSafe;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+use std::thread::JoinHandle;
+
+/// Run a JNI body, catching any panic at the FFI boundary and returning `default` instead.
+///
+/// A panic unwinding out of an `extern "system"` function aborts the whole process on Rust ≥ 1.81 —
+/// a hard crash of the embedding Android app with no logcat trace. This mirrors the discipline the C
+/// ABI already enforces (`punktfunk_core::abi` wraps every entry point in `catch_unwind`); the
+/// `panic = "unwind"` profile in the workspace `Cargo.toml` exists precisely so these guards work.
+/// We apply it to the teardown + background-thread shims (the "leaving a stream" path), where an
+/// unexpected panic (e.g. a poisoned `Mutex` during concurrent teardown) must degrade to a logged
+/// no-op rather than kill the app.
+pub(crate) fn jni_guard<T>(default: T, f: impl FnOnce() -> T) -> T {
+    std::panic::catch_unwind(AssertUnwindSafe(f)).unwrap_or_else(|_| {
+        log::error!("punktfunk JNI: caught a panic at the FFI boundary (returning default)");
+        default
+    })
+}
+
+/// A live session behind the `jlong` handle: the connector + the decode thread it feeds.
+pub(crate) struct SessionHandle {
+    // Read only by the android decode path (`nativeStartVideo` → `crate::decode`); on the host
+    // build (CI's workspace clippy/build) those readers are cfg'd out, so it's intentionally unused.
+    #[cfg_attr(not(target_os = "android"), allow(dead_code))]
+    pub client: Arc<NativeClient>,
+    /// Live decode stats, written by the decode thread and drained ~1 Hz by `nativeVideoStats`.
+    /// Session-lifetime (not per `VideoThread`) so the HUD's enable gate set via
+    /// `nativeSetVideoStatsEnabled` survives surface teardown/recreate and can land before
+    /// `nativeStartVideo` — enabling resets the window, so no stale data leaks across restarts.
+    pub stats: Arc<crate::stats::VideoStats>,
+    video: Mutex<Option<VideoThread>>,
+    #[cfg(target_os = "android")]
+    audio: Mutex<Option<crate::audio::AudioPlayback>>,
+    #[cfg(target_os = "android")]
+    mic: Mutex<Option<crate::mic::MicCapture>>,
+}
+
+struct VideoThread {
+    shutdown: Arc<AtomicBool>,
+    join: Option<JoinHandle<()>>,
+}
+
+impl SessionHandle {
+    /// Signal the decode thread to stop and join it. Idempotent.
+    fn stop_video(&self) {
+        if let Some(mut vt) = self.video.lock().unwrap().take() {
+            vt.shutdown.store(true, Ordering::SeqCst);
+            if let Some(j) = vt.join.take() {
+                let _ = j.join();
+            }
+        }
+    }
+
+    /// Stop + close audio playback. Dropping the [`crate::audio::AudioPlayback`] joins its decode
+    /// thread and closes the AAudio stream. Idempotent.
+    #[cfg(target_os = "android")]
+    fn stop_audio(&self) {
+        let _ = self.audio.lock().unwrap().take();
+    }
+
+    /// Stop mic uplink. Dropping the [`crate::mic::MicCapture`] joins its encode thread and closes
+    /// the AAudio input stream. Idempotent.
+    #[cfg(target_os = "android")]
+    fn stop_mic(&self) {
+        let _ = self.mic.lock().unwrap().take();
+    }
+}
+
+impl Drop for SessionHandle {
+    fn drop(&mut self) {
+        self.stop_video();
+        #[cfg(target_os = "android")]
+        self.stop_audio();
+        #[cfg(target_os = "android")]
+        self.stop_mic();
+    }
+}
+
+/// SHA-256 fingerprint → 64 lowercase hex chars (matches the host log + client-rs).
+fn hex32(fp: &[u8; 32]) -> String {
+    use std::fmt::Write;
+    fp.iter().fold(String::with_capacity(64), |mut s, b| {
+        let _ = write!(s, "{b:02x}");
+        s
+    })
+}
+
+/// 64-hex → [u8; 32]; `None` on bad length/char.
+fn parse_hex32(s: &str) -> Option<[u8; 32]> {
+    if s.len() != 64 {
+        return None;
+    }
+    let mut out = [0u8; 32];
+    for (i, b) in out.iter_mut().enumerate() {
+        *b = u8::from_str_radix(&s[2 * i..2 * i + 2], 16).ok()?;
+    }
+    Some(out)
+}

clients/android/native/src/session/planes.rs

@@ -0,0 +1,236 @@
+//! Plane start/stop: video (HEVC decode → Surface), host→client audio, mic uplink — plus the
+//! ~1 Hz decode-stats drain for the HUD.
+
+use jni::objects::JObject;
+use jni::sys::{jboolean, jdoubleArray, jlong, jsize};
+use jni::JNIEnv;
+
+use super::{jni_guard, SessionHandle};
+
+/// `NativeBridge.nativeStartVideo(handle, surface)` — wrap the SurfaceView's `Surface` as an
+/// `ANativeWindow` and start the HEVC decode thread rendering onto it. No-op if already started.
+#[cfg(target_os = "android")]
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStartVideo(
+    env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    surface: JObject,
+) {
+    use super::VideoThread;
+    use std::sync::atomic::AtomicBool;
+    use std::sync::Arc;
+
+    if handle == 0 {
+        return;
+    }
+    // SAFETY: live handle per the nativeConnect/nativeClose contract.
+    let h = unsafe { &*(handle as *const SessionHandle) };
+    let mut guard = h.video.lock().unwrap();
+    if guard.is_some() {
+        return; // already streaming
+    }
+    // SAFETY: `env`/`surface` are valid JNI pointers for this call. `as *mut _` bridges any
+    // jni-sys version skew between the `jni` and `ndk` crates (both are raw `*mut _` pointers).
+    let window = match unsafe {
+        ndk::native_window::NativeWindow::from_surface(
+            env.get_native_interface() as *mut _,
+            surface.as_raw() as *mut _,
+        )
+    } {
+        Some(w) => w,
+        None => {
+            log::error!("nativeStartVideo: no ANativeWindow from Surface");
+            return;
+        }
+    };
+    let shutdown = Arc::new(AtomicBool::new(false));
+    let client = h.client.clone();
+    let sd = shutdown.clone();
+    let st = h.stats.clone(); // session-lifetime stats (gate survives surface recreate)
+    let join = std::thread::Builder::new()
+        .name("pf-decode".into())
+        .spawn(move || crate::decode::run(client, window, sd, st))
+        .ok();
+    *guard = Some(VideoThread { shutdown, join });
+}
+
+/// `NativeBridge.nativeStopVideo(handle)` — stop + join the decode thread (without closing the
+/// session). No-op on `0`.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopVideo(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+) {
+    jni_guard((), || {
+        if handle != 0 {
+            // SAFETY: live handle per the contract.
+            let h = unsafe { &*(handle as *const SessionHandle) };
+            h.stop_video();
+        }
+    })
+}
+
+/// `NativeBridge.nativeVideoStats(handle): DoubleArray?` — drain ~1 s of decode stats for the HUD.
+/// Returns 14 doubles
+/// `[fps, mbps, latP50Ms, latP95Ms, latValid, skewCorrected, width, height, refreshHz, framesDropped,
+/// bitDepth, colorPrimaries, colorTransfer, chromaFormatIdc]`
+/// (the two flags are 1.0/0.0; the trailing four describe the negotiated video feed — see below), or
+/// `null` when no decode thread is running. Poll ~1 Hz from the UI; each call resets the measurement
+/// window. Not android-gated — pure `jni` + connector reads, so it links on the host build too
+/// (Kotlin only ever calls it on device).
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeVideoStats(
+    env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+) -> jdoubleArray {
+    jni_guard(std::ptr::null_mut(), || {
+        if handle == 0 {
+            return std::ptr::null_mut();
+        }
+        // SAFETY: live handle per the nativeConnect/nativeClose contract.
+        let h = unsafe { &*(handle as *const SessionHandle) };
+        if h.video.lock().unwrap().is_none() {
+            return std::ptr::null_mut(); // not streaming → no stats
+        }
+        let snap = h.stats.drain();
+        let mode = h.client.mode();
+        let color = h.client.color;
+        let buf: [f64; 14] = [
+            snap.fps,
+            snap.mbps,
+            snap.lat_p50_ms,
+            snap.lat_p95_ms,
+            if snap.lat_valid { 1.0 } else { 0.0 },
+            if snap.skew_corrected { 1.0 } else { 0.0 },
+            mode.width as f64,
+            mode.height as f64,
+            mode.refresh_hz as f64,
+            h.client.frames_dropped() as f64,
+            // Video-feed properties the host resolved at the handshake (Welcome): encode bit depth
+            // (8 / 10), the CICP colour primaries + transfer code points (Kotlin maps these to a
+            // colour-space / HDR label — transfer 16 = PQ, 18 = HLG ⇒ HDR), and the HEVC
+            // chroma_format_idc (1 = 4:2:0, 3 = 4:4:4). Static for the session unless renegotiated.
+            h.client.bit_depth as f64,
+            color.primaries as f64,
+            color.transfer as f64,
+            h.client.chroma_format as f64,
+        ];
+        let arr = match env.new_double_array(buf.len() as jsize) {
+            Ok(a) => a,
+            Err(_) => return std::ptr::null_mut(),
+        };
+        if env.set_double_array_region(&arr, 0, &buf).is_err() {
+            return std::ptr::null_mut();
+        }
+        arr.into_raw()
+    })
+}
+
+/// `NativeBridge.nativeSetVideoStatsEnabled(handle, enabled)` — gate per-frame stats sampling on the
+/// HUD actually being visible: while disabled the decode thread skips the clock read + lock per AU.
+/// Enabling resets the measurement window so a later show never reports stale data. Sticky for the
+/// session (survives video stop/start across surface recreation). No-op on `0`. Not android-gated —
+/// pure `jni` + an atomic store, so it links on the host build too.
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeSetVideoStatsEnabled(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+    enabled: jboolean,
+) {
+    jni_guard((), || {
+        if handle != 0 {
+            // SAFETY: live handle per the nativeConnect/nativeClose contract.
+            let h = unsafe { &*(handle as *const SessionHandle) };
+            h.stats.set_enabled(enabled != 0);
+        }
+    })
+}
+
+/// `NativeBridge.nativeStartAudio(handle)` — start the Opus→AAudio playback thread. No-op if already
+/// started or on a `0` handle. Best-effort: a failure leaves video streaming.
+#[cfg(target_os = "android")]
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStartAudio(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+) {
+    if handle == 0 {
+        return;
+    }
+    // SAFETY: live handle per the nativeConnect/nativeClose contract.
+    let h = unsafe { &*(handle as *const SessionHandle) };
+    let mut guard = h.audio.lock().unwrap();
+    if guard.is_some() {
+        return; // already playing
+    }
+    match crate::audio::AudioPlayback::start(h.client.clone()) {
+        Some(p) => *guard = Some(p),
+        None => log::error!("nativeStartAudio: playback init failed (video unaffected)"),
+    }
+}
+
+/// `NativeBridge.nativeStopAudio(handle)` — stop + join the audio thread and close AAudio (without
+/// closing the session). No-op on `0`.
+#[cfg(target_os = "android")]
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopAudio(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+) {
+    jni_guard((), || {
+        if handle != 0 {
+            // SAFETY: live handle per the contract.
+            let h = unsafe { &*(handle as *const SessionHandle) };
+            h.stop_audio();
+        }
+    })
+}
+
+/// `NativeBridge.nativeStartMic(handle)` — start mic capture (AAudio input → Opus → host `send_mic`).
+/// No-op if already running or on a `0` handle. Caller MUST hold RECORD_AUDIO; a failure (e.g. no
+/// permission) leaves the rest of the session streaming.
+#[cfg(target_os = "android")]
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStartMic(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+) {
+    if handle == 0 {
+        return;
+    }
+    // SAFETY: live handle per the nativeConnect/nativeClose contract.
+    let h = unsafe { &*(handle as *const SessionHandle) };
+    let mut guard = h.mic.lock().unwrap();
+    if guard.is_some() {
+        return; // already capturing
+    }
+    match crate::mic::MicCapture::start(h.client.clone()) {
+        Some(m) => *guard = Some(m),
+        None => log::error!("nativeStartMic: mic init failed (RECORD_AUDIO? — session unaffected)"),
+    }
+}
+
+/// `NativeBridge.nativeStopMic(handle)` — stop + join the mic thread and close the AAudio input
+/// stream (without closing the session). No-op on `0`.
+#[cfg(target_os = "android")]
+#[no_mangle]
+pub extern "system" fn Java_io_unom_punktfunk_kit_NativeBridge_nativeStopMic(
+    _env: JNIEnv,
+    _this: JObject,
+    handle: jlong,
+) {
+    jni_guard((), || {
+        if handle != 0 {
+            // SAFETY: live handle per the contract.
+            let h = unsafe { &*(handle as *const SessionHandle) };
+            h.stop_mic();
+        }
+    })
+}

clients/android/native/src/stats.rs

@@ -1,15 +1,22 @@
 //! Live decode stats for the on-stream HUD (mirrors the Apple client's stats overlay): FPS,
 //! receive throughput, and capture→client-receipt latency (p50/p95). The decode thread is the sole
 //! writer (`note` per access unit); the JNI accessor `nativeVideoStats` drains a snapshot ~1 Hz and
-//! resets the window. Pure `std` so it compiles on the host build too (the decode thread is
+//! resets the window. Sampling is gated on the HUD actually being visible (`set_enabled`, driven by
-//! android-only, but `VideoThread` holds the shared handle unconditionally).
+//! `nativeSetVideoStatsEnabled`) so the hidden steady state costs one relaxed atomic load per frame.
+//! Pure `std` so it compiles on the host build too (the decode thread is android-only, but
+//! `SessionHandle` holds the shared handle unconditionally).
 
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Mutex;
 use std::time::Instant;
 
 /// Rolling per-window accumulator. Rates are computed over the actual elapsed wall-time at drain
 /// (robust to poll jitter), so a poll that lands at 0.9 s or 1.1 s still reports the right FPS.
 pub struct VideoStats {
+    /// HUD gate: `note` runs on the per-frame decode path, so while the overlay is hidden it (and
+    /// the caller's latency computation — see `enabled`) early-outs on this flag alone. Off until
+    /// Kotlin shows the HUD.
+    enabled: AtomicBool,
     inner: Mutex<Inner>,
 }
 
@@ -35,11 +42,9 @@ pub struct Snapshot {
 }
 
 impl VideoStats {
-    // `new`/`note` are driven only by the android-only decode thread; `drain` (the JNI accessor) is
-    // ungated, so on the host build these two are unreferenced — that's expected, not dead code.
-    #[cfg_attr(not(target_os = "android"), allow(dead_code))]
     pub fn new() -> VideoStats {
         VideoStats {
+            enabled: AtomicBool::new(false),
             inner: Mutex::new(Inner {
                 window_start: Instant::now(),
                 frames: 0,
@@ -50,10 +55,44 @@ impl VideoStats {
         }
     }
 
+    /// Whether the HUD wants samples. The decode thread checks this BEFORE building a latency
+    /// sample, so the per-frame wall-clock read is skipped too while hidden.
+    // Read only by the android-only decode thread; unreferenced on the host build — expected.
+    #[cfg_attr(not(target_os = "android"), allow(dead_code))]
+    pub fn enabled(&self) -> bool {
+        self.enabled.load(Ordering::Relaxed)
+    }
+
+    /// Toggle sampling. Enabling resets the window, so the first HUD poll after a show never mixes
+    /// in counters (or a window start) from before the overlay was visible.
+    pub fn set_enabled(&self, on: bool) {
+        let was = self.enabled.swap(on, Ordering::Relaxed);
+        if on && !was {
+            let mut g = self
+                .inner
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner);
+            g.window_start = Instant::now();
+            g.frames = 0;
+            g.bytes = 0;
+            g.lat_us.clear();
+        }
+    }
+
     /// Record one decoded access unit: its wire size and (if in range) its capture→client latency.
+    // Driven only by the android-only decode thread; unreferenced on the host build — expected.
     #[cfg_attr(not(target_os = "android"), allow(dead_code))]
     pub fn note(&self, bytes: usize, lat_us: Option<u64>, skew_corrected: bool) {
-        let mut g = self.inner.lock().unwrap();
+        if !self.enabled.load(Ordering::Relaxed) {
+            return; // HUD hidden — skip the lock (the caller already skipped the clock read)
+        }
+        // Poison-proof: `note` runs per-frame on the decode thread, which has no catch_unwind —
+        // a panic elsewhere must not turn every later lock into a second panic (the counters
+        // stay consistent regardless).
+        let mut g = self
+            .inner
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
         g.frames += 1;
         g.bytes += bytes as u64;
         g.skew_corrected = skew_corrected;
@@ -64,7 +103,11 @@ impl VideoStats {
 
     /// Compute the window's rates + latency percentiles, then reset for the next window.
     pub fn drain(&self) -> Snapshot {
-        let mut g = self.inner.lock().unwrap();
+        // Poison-proof for the same reason as `note` — a poisoned window still drains fine.
+        let mut g = self
+            .inner
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
         let elapsed = g.window_start.elapsed().as_secs_f64().max(1e-3);
         let fps = g.frames as f64 / elapsed;
         let mbps = g.bytes as f64 * 8.0 / 1_000_000.0 / elapsed;