Replace the original 2018 Bootlin upstream README with the
fourier-fork situation as of May 2026. What works: fresnel 5/5,
ampere iter1+2, ohm baseline (all RK family, mainline VDPU381/383
landing Feb 2026 helps).
What doesn't: Pi 5 HEVC via this backend. New 'The Pi 5 standoff'
section captures the honest situation surfaced by the May 2026
web-research pass:
- Kwiboo's ffmpeg-v4l2request hwaccel: 8 years un-merged upstream
- libva-v4l2-request: no commits since ~2021
- rpi-hevc-dec mainline: 17 months in review, still not merged;
Pi 6.18.x downstream has active HEVC regressions (#7228, #7306)
- Mozilla bug 1969297 picks the ffmpeg-hwaccel-context path, not
libva — explicit ack that strict drivers need libavcodec's
internal SPS context
- Frames the issue as ecosystem coordination failure (principal-
agent stalemate), not architectural impossibility
Notes that iter40 + iter40b lands but parks: backend infra is
sound + reusable for any future strict V4L2 stateless target ffmpeg
ships before libva does, but the user-facing Pi 5 HEVC story will
not come from this backend — it'll come from Mozilla / Kwiboo /
upstream coordination unblocking.
iter38 5/5 fresnel + 9-profile ampere baselines preserved
post-iter40b — documented as no-regression in phase7_pi5_hevc_close.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This patch introduces the support of MPEG4 video decoding. It basically
just copies data from VA's frame/slice headers data structures to v4l's
MPEG4 frame header extended controls data structures.
This patch introduces the support of MPEG2 video decoding. It basically
just copies data from VA's frame/slice headers data structures to v4l's
MPEG2 frame header extended controls data structures.
This VA backend uses v4l2's Frame API proposal to interface with the
"sunxi-cedrus" video driver on Allwinner SoC. Only a few parts of the
code are really dependent on sunxi-cedrus and this VA backend could be
reused for other v4l drivers using the Frame API.
claude-noether
Thomas Petazzoni