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>
This commit is contained in:
2026-07-02 11:04:43 +02:00
parent b357934cb1
commit c890de49c9
18 changed files with 1922 additions and 1532 deletions
+128 -97
View File
@@ -129,109 +129,140 @@ impl AudioPlayback {
let jitter_headroom = JITTER_HEADROOM_MS * ms;
let hard_cap_max = HARD_CAP_MS * ms;
let counters = Arc::new(Counters::default());
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
// realtime callback never frees heap (Android's Scudo allocator has unbounded free() tail
// latency — a free on the audio thread is an XRun = a click) and the decode thread 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
// 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
// before the trim below = the hard cap plus one full channel of 5 ms (480-f32) frames — the
// punktfunk protocol always sends 5 ms Opus frames (host `audio_thread`); a larger frame
// would force a one-time realloc, asserted (not silently corrupted) in `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)
let mut last_xrun: i32 = 0; // last AAudio XRun count we grew the buffer for
let callback = move |s: &AudioStream, data: *mut c_void, num_frames: i32| {
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
// each Vec but keeps its capacity, then the empty buffer is handed back for 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;
// drop-oldest only above a wide ~120 ms band. Decoupled from the AAudio burst `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 {
ring.pop_front();
}
if !primed && ring.len() >= target {
primed = true;
}
if primed {
for slot in out.iter_mut() {
*slot = ring.pop_front().unwrap_or(0.0);
// 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 realtime callback never frees heap (Android's Scudo allocator has unbounded free()
// tail latency — a free on the audio thread is an XRun = a click) and the decode thread
// 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 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 before the trim below = the hard cap plus one full channel of 5 ms (480-f32)
// frames — the punktfunk protocol always sends 5 ms Opus frames (host `audio_thread`); a
// larger frame would force a one-time realloc, asserted (not silently corrupted) in
// `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)
let mut last_xrun: i32 = 0; // last AAudio XRun count we grew the buffer for
let callback = move |s: &AudioStream, data: *mut c_void, num_frames: i32| {
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 each Vec but keeps its capacity, then the empty buffer is handed back for
// 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; drop-oldest only above a wide ~120 ms band. Decoupled from the AAudio burst
// `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 {
ring.pop_front();
}
if !primed && ring.len() >= target {
primed = true;
}
if primed {
for slot in out.iter_mut() {
*slot = ring.pop_front().unwrap_or(0.0);
}
cb_counters
.pcm_written
.fetch_add(num_frames as u64, Ordering::Relaxed);
} else {
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 every momentary drain costs a fresh 40 ms silence (the old behaviour,
// self-inflicted crackle on any jitter spike).
if ring.is_empty() {
empties += 1;
if empties >= DEPRIME_AFTER_CALLBACKS {
primed = false;
}
} else {
empties = 0;
}
cb_counters
.pcm_written
.fetch_add(num_frames as u64, Ordering::Relaxed);
} else {
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
// every momentary drain costs a fresh 40 ms silence (the old behaviour, self-inflicted
// crackle on any jitter spike).
if ring.is_empty() {
empties += 1;
if empties >= DEPRIME_AFTER_CALLBACKS {
primed = false;
.ring_depth
.store(ring.len() as u64, Ordering::Relaxed);
// Google's AAudio anti-glitch technique: when the device reports new XRuns, grow the
// HW buffer by one burst (up to capacity). getXRunCount + setBufferSizeInFrames are
// 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();
if xr > last_xrun {
last_xrun = xr;
let burst = s.frames_per_burst().max(1);
let grown =
(s.buffer_size_in_frames() + burst).min(s.buffer_capacity_in_frames());
let _ = s.set_buffer_size_in_frames(grown);
}
}
} else {
empties = 0;
}
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
// buffer by one burst (up to capacity). getXRunCount + setBufferSizeInFrames are 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();
if xr > last_xrun {
last_xrun = xr;
let burst = s.frames_per_burst().max(1);
let grown =
(s.buffer_size_in_frames() + burst).min(s.buffer_capacity_in_frames());
let _ = s.set_buffer_size_in_frames(grown);
}
}
AudioCallbackResult::Continue
AudioCallbackResult::Continue
};
let stream = AudioStreamBuilder::new()?
.direction(AudioDirection::Output)
.sample_rate(SAMPLE_RATE)
// The wire order (FL FR FC LFE RL RR SL SR) is the standard AAudio/Android channel
// order, so this is an IDENTITY mapping — no permute. AAudio infers the 5.1/7.1 mask
// from `channel_count` (the ndk crate's builder exposes no setChannelMask); the host
// captures + Opus-encodes in exactly this order.
.channel_count(channels as i32)
.format(AudioFormat::PCM_Float)
.performance_mode(AudioPerformanceMode::LowLatency)
.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()?;
Ok((stream, tx, free_rx))
};
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
// order, so this is an IDENTITY mapping — no permute. AAudio infers the 5.1/7.1 mask
// from `channel_count` (the ndk crate's builder exposes no setChannelMask); the host
// captures + Opus-encodes in exactly this order.
.channel_count(channels as i32)
.format(AudioFormat::PCM_Float)
.performance_mode(AudioPerformanceMode::LowLatency)
.sharing_mode(AudioSharingMode::Shared)
.data_callback(Box::new(callback))
.error_callback(Box::new(|_s, e| {
log::warn!("audio: AAudio error (device reroute/disconnect?): {e:?}");
}))
.open_stream()
.map_err(|e| log::error!("audio: open_stream: {e}"))
.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}");