gramps
76f51e6f4e
ty-1723/1726 device takes showed accelerated playback + audio tail cut-off:
a render overrun (~35ms vs the 16.6ms slot) SKIPPED the missed slots (slice 10's
freshness choice), so a 60fps-authoring pump wrote one frame per 35ms into a
60fps container — 1723: 697 frames/11.62s vs 11.84s audio; 1726: 163/2.72s vs
2.93s, video ending 0.21-0.24s early.
OBS never leaves a wall-time hole: the video thread emits one frame per tick and
a lagging producer DUPLICATES the newest frame ("lagged frames due to rendering
lag/stalls" — obs-output.c; "If the video frame queue is full, it will duplicate
the last frame" — docs.obsproject.com/backend-design). The pump's submit is now a
bounded catch-up over the missed slots (while now >= nextTick), fresh on the first,
repeated after — duration == wall, judder not fast-forward. Safe because Channel.
TryWrite never blocks (the take-9 smear was the blocking pipe-write; each emit is
nanoseconds). Burned frame index moved inside the loop: every emitted slot carries
its own +1 (also fixes the old unconditional pre-gate bump that gapped the judge
sequence on non-submitting fast-render iterations).
Good Dog test: Pump_Overrun_Renders_EmitsEverySlot_NotSkipped (60fps, 35ms render
cost, asserts >=0.65 of the wall slots emitted). 294/294 green, 0 warnings.
No push — web/A/V work is commit-local until greenlight.
91 lines
5.5 KiB
Markdown
91 lines
5.5 KiB
Markdown
# HANDOFF — 2026-09-14 (composition capture DEVICE-VERIFIED ✓; slice-15 pacing fix committed locally — A/V re-measure next)
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## Branch / Commit State
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`main` HEAD = **slice-15 commit** (FramePump duplicate-on-lag pacing — committed LOCALLY, **NOT
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pushed**; web/A/V work stays commit-local until greenlight). Before it: `c01206f` (composition
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capture redesign, also local/unpushed), before that `b22d08e` (signed audio-sync, pushed).
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Working tree **clean**.
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## ⚠️ Branding (2026-09-14, creator-corrected): product = **llamacasty**, internals = ytLive
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The product is **llamacasty**; repo path, csproj `AssemblyName`/`RootNamespace`, DB/log paths
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(`%APPDATA%\ytLlive\...`), and most code names are the legacy **ytLive/ytLlive**. User-facing
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language says "llamacasty"; code/assembly/repo names stay ytLive. See `ai.md` → Brand.
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## ✅ DEVICE-VERIFIED — composition capture looks good; then the A/V defect surfaced
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The creator ran real takes off the `c01206f` build and reports the video looks **very good** — the
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Windows.Graphics.Capture web path is confirmed on device (open item closed). BUT the same takes
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showed the A/V defect we have seen before: **both desktop and webcam playback are accelerated, the
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audio "gets speedier", then cuts off at the end.**
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## 🔬 Sliced and measured (evidence)
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With the A/V recipe (`MyMistakes.md` → "Measuring audio-video A/V sync" + `/tmp/opencode/avsync.py`):
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- `ty-20260914-1723-0000-2.mp4`: 697 video frames @60fps = **11.62s** vs audio **11.84s**.
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- `ty-20260914-1726-0000-2.mp4` (clap take): 163 frames = **2.72s** vs **2.93s** audio. Video ends
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0.21–0.24s before audio → the cut-off. Clap: audio env peak 1.655s vs video motion 0.75–1.03s;
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cross-correlation lag **+0.667s** (audio late).
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- `startup.log`: `FramePump stall: iteration 33-46ms (> 2× the 17ms interval): worst render 33ms …
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dropped 0`.
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**Root cause (slice 15):** slice 10's freshness choice skipped the overrun's missed slots — one
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fresh frame per ~35ms stall authored into a 60fps container = **accelerated playback**. OBS's
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answer is duplicate-on-lag (`libobs/video-io.c`, docs.obsproject.com/backend-design): fill each
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missed slot by repeating the newest frame — duration == wall, judder never fast-forward.
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## 🔬 Committed locally — slice 15: one frame per deadline slot (duplicate-on-lag)
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**What:** `Services/Encoder/FramePump.cs` submit is now a bounded catch-up —
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`while (now >= nextTick) { submit latest composite; nextTick += intervalTicks; }` clamped to a
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`deadlineNow` captured once per iteration. First missed slot gets the fresh composite, the rest get
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repeats of it (OBS duplication) — recording duration == wall time under any render load, no
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acceleration, no audio tail cut. The burned `_outputIndex` moved inside the submit loop (every
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emitted slot gets its own +1; also fixes the old unconditional bump that gapped the judge sequence
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on non-submitting fast-render iterations).
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**Good Dog test:** `ytLive.Tests/FramePumpTests.cs` → `Pump_Overrun_Renders_EmitsEverySlot_NotSkipped`
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(60fps, 35ms render cost, asserts ≥0.65 of the wall slots emitted — the old skip-pump wrote ~1/35ms).
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**294/294 green, app build 0 warnings.** Files: `Services/Encoder/FramePump.cs`,
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`ytLive.Tests/FramePumpTests.cs`. Docs in same commit: ai.md Slice 15, MyMistakes (supersedes the
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slice-10 "no burst re-write" clause + latest numbers), this HANDOFF.
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## ⚠️ Open items (before PUSHABLE)
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- **Device re-verify:** a take on the slice-15 build must play at REAL time (no acceleration, no
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cut-off audio tail). Confirm via ffprobe: video stream duration ≈ audio ≈ container.
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- **Re-measure the true A/V offset** with a clap take now that video pacing is honest
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(`/tmp/opencode/avsync.py`). The +0.6s reading on 1726 was confounded by the 1.1x
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acceleration. If a real residual remains after the pacing fix, the backlog is the AUDIO pipeline
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(mixer ring / advance), not video.
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- **No push yet** — commit-locally-until-greenlight for web/A/V work.
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## Open threads (carried)
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- Audio-silence verification — fixed (`724af14`); creator heard real audio.
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- Webcam MJPG missing / ~10–14Hz, layer SortOrder, truncation-with-dynamic-scenes — queued.
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- Sync control user-doc tutorial — REQUIRED before 1.0 (creator directive; TASK 22).
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- Signed A/V sync: verify the negative (advance) direction on device.
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## Landmines
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- testhost shares startup.log — filter by time.
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- `cmd.exe /c "taskkill /F /IM ytLive.exe"` (WSL double-slashes mangle) before rebuilds — a live
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app process locks `ytLive.exe` and the apphost copy fails (MSB3021, seen today).
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- Build/tests: **Windows dotnet host** (`/mnt/c/Program Files/dotnet/dotnet.exe`). 0 warnings —
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only `./scripts/verify.sh "<files>"`'s clean build counts. Building `ytLive.csproj` alone does
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NOT rebuild `ytLive.Tests.dll` — run the Tests csproj before `vstest`.
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- ffmpeg/ffprobe: `/mnt/c/Program Files/Krita (x64)/bin/` with Windows paths.
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- `MyMistakes.md` has the **A/V sync measurement recipe**, the **deadline-pacing** lessons
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(item 1 + slice 15), and the **CoreMessaging DQ recipe** — grep before re-deriving.
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- sqlite3 at `/home/gramps/android-sdk/platform-tools/sqlite3` for
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`/mnt/c/Users/gramp/AppData/Roaming/ytLlive/ytLlive.db`.
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## Next step
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Have the creator record a clap take on the slice-15 build → ffprobe durations (video == audio ==
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wall) + `/tmp/opencode/avsync.py` for the honest offset. If durations match, the acceleration
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defect is closed; then decide push with the user, and attack any true audio-latency residual as its
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own work unit. |