phase 0 close: deliverables 5 + 6 — fixtures + cross-validator anchor
Closes Phase 0 for fresnel-fourier. Per-codec test fixtures and
cross-validator contract traces complete the campaign-locked
boolean-correctness baseline.
Deliverable #5 — per-codec test fixtures (test_fixtures.md):
Generated 4 new fixtures on fresnel from the bbb_1080p30_h264.mp4
master via stock ffmpeg (libx265 ultrafast, libvpx-vp9 speed 5,
mpeg2video, libvpx vp8). All 720p 10s 8-bit yuv420p — matching the
silicon-supported profile/pixfmt for each codec on RK3399:
bbb_720p10s_hevc.mp4 620 KB (HEVC Main, rkvdec target)
bbb_720p10s_vp9.webm 3.4 MB (VP9 Profile 0, rkvdec target)
bbb_720p10s_mpeg2.ts 5.3 MB (MPEG-2 Main, hantro-vpu-dec target)
bbb_720p10s_vp8.webm 2.4 MB (VP8, hantro-vpu-dec target)
Encode wall times on fresnel: HEVC 13s, VP9 93s, MPEG-2 6s, VP8 26s.
H.264 master is 725 MB carryover from libva-multiplanar / fourier_attribution.
Deliverable #6 — cross-validator anchor (cross_validator_traces.md):
phase0_findings.md named chromium-fourier 149 as the cross-validator;
that package isn't installed on fresnel and marfrit-packages isn't
configured (no auto-install path tonight). Substituted ffmpeg
-hwaccel v4l2request as a better-fit cross-validator: it's an
independent V4L2 client (uses no libva at all, lives in
libavcodec/v4l2_request*.c), already on the box (stock
ffmpeg n8.1-13-gb57fbbe50c, the Kwiboo v4l2-request-n8.1 branch),
and implements all 5 codecs the campaign locked.
Headline finding: ALL 5 CODECS WORK end-to-end via the kernel
direct path on RK3399.
ffmpeg -hwaccel v4l2request -i bbb_<codec>.<ext> -frames:v 2 -f null -
H.264: exit 0
HEVC: exit 0
VP9: exit 0
MPEG-2: exit 0
VP8: exit 0
The Linux kernel + rkvdec + hantro-vpu drivers are solid for the
entire campaign codec scope. Phase 6 work scope is purely libva-
backend code — no kernel patches, no upstream Linux engagement.
Per-codec libva (iter8) vs ffmpeg-v4l2request status sweep:
H.264 libva: PASS (T4 PASS + bit-exact pixel verify) | ffmpeg-v4l2req: PASS
HEVC libva: vaCreateConfig=12 (UNSUPPORTED_PROFILE) | ffmpeg-v4l2req: PASS
→ src/h265.c is excluded in src/meson.build but src/config.c:151
enumerates HEVCMain via V4L2_PIX_FMT_HEVC_SLICE probe;
vaCreateConfig fails downstream of the case match.
VP9 libva: profile not enumerated | ffmpeg-v4l2req: PASS
→ no vp9.c in fork
MPEG-2 libva: vaCreateConfig=12 (UNSUPPORTED_PROFILE) | ffmpeg-v4l2req: PASS
→ mpeg2.c IS compiled, config.c:64-65 has the case statements,
yet vaCreateConfig rejects. Phase 2 source-read needed.
VP8 libva: profile not enumerated | ffmpeg-v4l2req: PASS
→ no vp8.c in fork
Suggested Phase 6 iteration order (subject to Phase 1 lock):
iter1: MPEG-2 — likely cheapest (config.c-level path; mpeg2.c
already compiled)
iter2: HEVC — re-enable h265.c in build, audit against rkvdec
iter3: VP8 — implement vp8.c on hantro
iter4: VP9 — implement vp9.c on rkvdec (largest control surface)
Per-codec ioctl frequency anchor (2-frame ffmpeg -hwaccel v4l2request):
ioctl H.264 HEVC VP9 MPEG-2 VP8
VIDIOC_DQBUF 45 49 40 26 49
VIDIOC_QBUF 22 24 20 10 20
VIDIOC_CREATE_BUFS 17 17 17 12 17
VIDIOC_QUERYBUF 15 15 15 10 15
VIDIOC_S_EXT_CTRLS 13 14 11 5 10
VIDIOC_EXPBUF 11 11 11 6 11
VIDIOC_QUERY_EXT_CTRL 0 5 0 0 0
MEDIA_IOC_REQUEST_ALLOC 4 4 4 4 4
DMA_BUF_IOCTL_SYNC 0 0 0 4 0
MEDIA_REQUEST_IOC_REINIT 0 0 0 0 3
Architectural divergence ffmpeg-v4l2request vs libva-v4l2-request-fourier:
- ffmpeg uses VIDIOC_EXPBUF + DMA-BUF for downstream readback.
Our libva backend uses cached mmap via vaDeriveImage — the
iter1 patch-0011 cache-stale bug class. Phase 4 work item
consistent with T4's finding: adding VIDIOC_EXPBUF + DMA-BUF-
backed image export to the libva backend would fix the
cache-coherency issue identified in T4's H.264 readback.
- ffmpeg uses 4 request_fds pooled. Our backend uses 16 (iter6
per-OUTPUT-slot binding). Both valid; different pool depth.
- HEVC alone needs VIDIOC_QUERY_EXT_CTRL for hevc_slice_params
dynamic-array introspection — unique among the 5 codecs.
Substrate change deferred (not a Phase 0 blocker): chromium-fourier
149 install on fresnel is Phase 1+ work. When done, a follow-up
trace pass per codec will cross-check ffmpeg-v4l2request and
chromium contracts. For Phase 0 baseline, ffmpeg-v4l2request is
the anchor.
Phase 0 fully closed. Six deliverables landed. Phase 1 lock can proceed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
claude-noether
b74551bc56