FfmpegEncoder resolved the encoder name into its OWN StreamHealth instance, while the view
model read CurrentHealth — a different object. So every recorded session was filed as
"unknown", and the rate history's encoder key (evidence about NVENC says nothing about QSV)
had nothing to key on. The name now travels on the encoder interface and the pump forwards
it: IFfmpegEncoder.VideoEncoderName -> FramePump.EncoderName.
Caught while adding it: reading _framePump.EncoderName from RefreshRateProposal throws,
because that call runs at MainViewModel ctor line 354 and the pump is built at line 468.
Eight tests failed with the same NullReferenceException, which took a while to see because
the harness's test output is buffered — the first honest look at per-test logging named it
in one line. Guarded; the history falls back to the last session's encoder for that tier,
which is exactly the pre-first-session case the fallback already existed for.
Tests: FramePumpTests gains the encoder-name assertion (null before start, h264_nvenc
after), and the three fake encoders implement the new member.
675 pass, 0 warnings.
slice 9 made the DURATION right but content still hiccuped; aggregates (301/300, uniform
file PTS) could not see it. Measured root cause: FfmpegEncoder.SubmitFrameAsync BLOCKED
on WriteAsync(8.3MB)+FlushAsync when ffmpeg lagged the pipe, and the burst while-loop
re-wrote that same stale composite per crossed slot — frozen runs.
OBS shape (derivative, wrapped pre-1.0): the encoder queue in libobs/obs-encoder.c —
encoder thread never couples back into the video thread; overflow = dropped data, never
a frozen producer. https://github.com/obsproject/obs-studio/blob/master/libobs/obs-encoder.c
- FfmpegEncoder: SubmitFrameAsync is now an enqueue (ArrayPool copy) into a bounded
Channel (cap 120) drained by its own task; drop-newest + count when full;
StopAsync flushes the queue then EOF (TryComplete). IFfmpegEncoder.DroppedFrames.
- FramePump: ONE fresh composite per iteration (burst loop deleted); worst-submit stat,
stall logger (>2x interval names the stage), dropped/stalls in stats.
- Burned-in 6-digit dot-matrix frame counter (white box, bottom-right) on every composite
— the clock-independent judge replacing the WSL ticker: +1/frame, jumps = counted drops.
- ONE new test Backpressure_QueueOverflow_DropsFrames_AndNeverBlocks (slow-sink fake:
submit never blocks, drops counted, stop flushes exactly submitted-minus-dropped).
- Full suite 290 tests, 289 pass — sole failure the pre-existing compositor pixel test.
- Docs same-commit: ai.md slice 10 (+ encoder/stop-note corrections), MyMistakes point 8,
HANDOFF.
Audio untouched (queued follow-up); web overlay still frozen pending timing closure.