Major iteration result on av1-iter1 backend branch (tip c839b94 both
ampere and noether). AV1 hardware decode is FUNCTIONALLY WORKING for
the common cases:
Fixture Result
test_av1.ivf (2 frames, no grain) bit-exact PASS 2/2
av1-1-b8-02-allintra.ivf (39 all-intra) bit-exact PASS 10/10
av1_larger.ivf (film_grain + show_existing) 3/10 PASS (apply_grain=1 IDR-derived)
av1-1-b10-23-film_grain-50.ivf (10-bit) both libva + kdirect 0 bytes (vpu981 may not support)
The 10/10 all-intra PASS is the load-bearing validation: it proves
our backend's V4L2 control submission, OUTPUT byte assembly, surface
management, reference timestamp plumbing, and per-codec dispatch
are all correct for the common AV1 case.
The remaining 7/10 divergence on the film_grain+show_existing
fixture is localized via patched-libavcodec dump (LD_LIBRARY_PATH
override on debug fwrite-instrumented libavcodec.so) to:
- First 7 EndPicture submissions byte-IDENTICAL to kdirect for
SEQUENCE + FRAME + TILE_GROUP_ENTRY + FILM_GRAIN ctrls AND for
OUTPUT byte payload.
- libva has 2 EXTRA EndPicture calls on REUSED surfaces (the
ffmpeg-vaapi AV1 hwaccel's show_existing_frame handling).
- iter2 Fix 3 release-on-rebind FALSIFIED as the cause
(LIBVA_SKIP_REBIND=1 A/B identical to default).
Fix space (Phase 4): cap_pool refactor to track N surfaces per
slot, OR ffmpeg-vaapi AV1 hwaccel surface-allocation change.
All diagnostic infrastructure retained for next iteration:
/tmp/diff_av1_ctrls.py on ampere (per-CID strace byte diff)
/tmp/ivf_split.py on ampere (per-frame IVF extraction)
LIBVA_V4L2_DUMP_OUTPUT env on backend (libva-side OUTPUT bytes)
patched libavcodec build instructions in close doc
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
marfrit