User pick at iter8 open. Carried unchanged through 5 iters (iter4..iter7);
keyframe partially decodes (frame-1 first 16 bytes = real chroma) while
inter frames return all-zero. Pass criterion: libva_h264 == kdirec_h264
== sw_h264 byte-identical for bbb_1080p30_h264.mp4 3-frame, including
inter frames.
In scope: src/h264.c, src/h264_slice_header.c, src/picture.c H.264 paths,
per-frame request_fd lifecycle. Out of scope: VP9/VP8/HEVC/MPEG-2, kernel
patches, performance, all other backlog items.
Substrate at iter8 open: fork tip 6df2159 (iter7), backend SHA 520507f6..,
kernel linux-fresnel-fourier 7.0-1, auto-detect picks rkvdec on every boot.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
