 marfrit
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abd97e3eb6
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iter8 Phase 2: H.264 backend source-read + refined hypothesis surface
Maps the per-frame decode pipeline (BeginPicture → RenderPicture →
EndPicture → SyncSurface) and walks frame-1 IDR + frame-2 P state
transitions through h264_set_controls and the DPB.
Eliminates 6 of 13 hypotheses from Phase 0 by source-read alone (H-A
DPB stale, H-B POC sentinel for small POCs, H-C SLICE flags in FRAME_BASED,
H-D request_fd lifecycle, H-F pred-weight, H-G scaling matrix re-upload).
Adds 4 new hypotheses (H-J reference_ts derivation, H-K CAPTURE buf count,
H-L slice_data alignment vs h264_start_code, H-M frame_num cross-check).
Live hypotheses for Phase 3: H-E (CAPTURE rotation/reference-resolution),
H-H (start_code prefix), H-L (slice_data alignment), H-K (cap_pool size).
Phase 3 plan: strace-diff libva-vaapi-H.264 vs kdirect-H.264 on the same
fixture; byte-level frame-1/2/3 examination; dmesg check.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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2026-05-13 11:19:49 +00:00 |
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