feat(clients/android): OnFrameRendered display stage — HUD headline becomes capture→displayed
The long-deferred Android display stage (design/stats-unification.md; plan 4.1 of design/client-parity-and-network-resilience.md): AMediaCodec_setOnFrameRenderedCallback (API 26, under the minSdk-28 floor ⇒ hard-linked via ndk-sys) reports SurfaceFlinger's per-frame render timestamp, giving the HUD the spec's `display` = decoded→displayed term and the directly-measured capture→displayed end-to-end headline on both decode loops. Falls back per spec to the v1 capture→decoded endpoint on any window without render callbacks (the platform may drop them under load), and to it permanently if registration is refused. - The render timestamp arrives on CLOCK_MONOTONIC; it's re-based onto CLOCK_REALTIME against monotonic-now at callback time, which also cancels the (batchable) callback delivery lag. - The `ndk` crate exposes neither the callback nor the codec pointer needed to bind it raw, so the workspace pins `ndk` 0.9.0 to a vendored copy (clients/android/native/ vendor/ndk) whose ONLY change makes MediaCodec::as_ptr public — the "as_ptr patch". Workspace-excluded so host builds never compile it; drop when upstream exposes either. - nativeVideoStats grows to 26 doubles (22–25: dispValid, displayP50, e2eDispP50/P95; 0–21 unchanged for older readers); StatsOverlay moves headline endpoint + equation together so the equation always tiles the headline interval. Verified: host cargo check/test/clippy, aarch64-linux-android check/clippy, Kotlin app+kit+tests compile, roborazzi HUD render shows the full 4-term equation. Device verification rides plan 4.2's phone A/B. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
@@ -74,7 +74,7 @@ always spelled out rather than pretending:
|
||||
| client | headline | why |
|
||||
|---|---|---|
|
||||
| Windows, macOS/iOS (Metal presenter), Linux | `capture→on-glass` / `capture→displayed` | present instant available (GTK measures at hand-off to the compositor, which adds about one compositor cycle after it) |
|
||||
| Android | `capture→decoded` | the display hand-off happens inside MediaCodec/SurfaceView where precise present timing isn't exposed |
|
||||
| Android | `capture→displayed` | MediaCodec's per-frame render callback reports SurfaceFlinger's render timestamp; on the rare window where no callback is delivered (the platform may drop them under load) the HUD falls back to `capture→decoded` |
|
||||
| macOS/iOS fallback presenter | `capture→received` | the system video layer hides decode and present timing entirely |
|
||||
|
||||
A shorter chain means the number is **smaller because it measures less** — check the
|
||||
|
||||
Reference in New Issue
Block a user