T

claude-noether b74551bc56 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>

2026-05-07 21:52:21 +00:00

phase0_evidence/2026-05-07

phase 0 close: deliverables 5 + 6 — fixtures + cross-validator anchor

2026-05-07 21:52:21 +00:00

.gitignore

phase 0 deliverable 4: H.264 baseline trace — PASS boolean correctness

2026-05-07 21:32:36 +00:00

phase0_findings.md

phase 0 corrections: hantro RK3399 has no H.264; substrate is iter8 master

2026-05-07 20:57:40 +00:00

phase0_recovery_2026-05-07.md

phase 0 deliverables 1-3: SDDM watchpoint, V4L2 inventory, iter8 fork smoke

2026-05-07 20:54:38 +00:00

README.md

phase 0 corrections: hantro RK3399 has no H.264; substrate is iter8 master

2026-05-07 20:57:40 +00:00

README.md

fresnel-fourier

TL;DR

Peer campaign to libva-multiplanar, targeting fresnel (Pinebook Pro / Rockchip RK3399) instead of ohm (PineTab2 / RK3566). Same deliverable shape — make libva-v4l2-request-fourier work end-to-end, for production VA-API consumers — but on a different SoC with a different (and broader) V4L2 decoder surface.

The libva backend fork itself (libva-v4l2-request-fourier) is shared: it lives at ../libva-multiplanar/libva-v4l2-request-fourier/. This campaign does not nest a second copy. Code-side work that turns out to be RK3399-specific lands either as #ifdef/runtime-detected paths inside that fork's master or, if scope diverges sharply, on a feature branch — Phase 2 source-read of each iteration decides.

Origin

libva-multiplanar reached iter5-close on 2026-05-05 with the ohm path solid: hantro (rk3568-vpu DT compatible) decodes H.264 to NV12 dmabufs end-to-end, three iterations of bugs fixed, mpv --hwdec=vaapi smooth, firefox-fourier RDD-sandboxed Firefox engages the backend without MOZ_DISABLE_RDD_SANDBOX=1, chromium-fourier 149 confirmed as the regression-check consumer.

That campaign's README explicitly names fresnel (RK3399) and ampere/boltzmann (RK3588) as "future iterations after ohm path is solid" (libva-multiplanar/README.md:87). fresnel-fourier is the formal peer campaign for the RK3399 leg of that promise.

Topology choice (LOCKED 2026-05-07): peer campaign, not child of libva-multiplanar. Each runs its own 8(+1) phase loop. Cross-link only — fresnel-fourier results do not gate libva-multiplanar's Phase 8 close (which already happened iteration-by-iteration on ohm).

Hardware target

fresnel — Pinebook Pro laptop. See reference_fresnel_kernel_constraints.md for the custom-OC-kernel discipline (don't let pacman -Syu clobber the OC DTB) and project_fresnel.md for fleet placement.

Property	Value
SoC	Rockchip RK3399 (2× Cortex-A72 + 4× Cortex-A53)
GPU	Mali-T860 MP4 (Midgard, panfrost)
Decoder block 1	rkvdec (`/dev/video3`) — H.264 + HEVC + VP9
Decoder block 2	hantro-vpu-dec (`rk3399-vpu-dec`, `/dev/video5`) — MPEG-2 + VP8 (RK3399 hantro does not advertise H.264; corrected 2026-05-07 from empirical V4L2 enumeration — see `phase0_evidence/2026-05-07/v4l2_inventory_findings.md`)
Encoder block	hantro-vpu-enc (`/dev/video4`) — JPEG only
OS	EndeavourOS-ARM (Arch derivative; same pacman + marfrit-packages mechanism as ohm)
Kernel	`linux-eos-arm 6.19.9-99` — CONFIG_FTRACE=y, CONFIG_FUNCTION_TRACER=y, CONFIG_DYNAMIC_FTRACE=y, CONFIG_TRACING=y verified 2026-05-07. No rebuild needed for trace work.

The decode-side surface area is genuinely broader than ohm. ohm has hantro (H.264 + MPEG-2 + VP8) and an rkvdec block whose mainline rkvdec2/vdpu346 driver isn't merged. fresnel has hantro (MPEG-2 + VP8 only — empirical, see correction note in the table above) plus a fully-driven mainline rkvdec covering H.264 + HEVC + VP9. So this campaign exercises codecs (HEVC, VP9) the libva-v4l2-request-fourier fork has never run on real hardware to date, and there is exactly one decoder bind for H.264 (rkvdec) — no two-block routing decision.

GPU side: panfrost on Mali-T860 (Midgard) is a different generation than ohm's Mali-G52 (Bifrost). KWin / Mesa / panfrost stack regressions or wins on T860 are not assumed to track G52 — the kwin-fourier verdict from fourier_attribution doesn't transfer for free.

Scope (LOCKED 2026-05-07 in phase0_findings.md)

In scope:

libva-v4l2-request-fourier backend exercised on fresnel V4L2 decode nodes (rkvdec + hantro-vpu-dec).
Codecs: everything decode-capable — H.264 + HEVC + VP9 (via rkvdec) + MPEG-2 + VP8 (via hantro-vpu-dec). This is the explicit broadening from libva-multiplanar's H.264-first locked scope.
Test consumers: vainfo, mpv --hwdec=vaapi, Firefox via media.ffmpeg.vaapi.enabled, chromium-fourier 149 (regression check).
Phase 1 success criterion (matching libva-multiplanar): boolean correctness — "libva accepted + providing access to hardware decoder for each codec." Performance metrics deferred.
Phase 0 task 1: recover fresnel from the SDDM greeter crash-loop (per ~/.claude/plans/dynamic-forging-piglet.md). Recovery is bookkept as substrate work inside this campaign, not as a separate prereq.

Out of scope:

Front-end libva (API library). Backend only.
Other hardware (ohm + ampere/boltzmann are libva-multiplanar's iterations).
AV1 (no decoder block on RK3399 supports it).
Performance metrics — fresnel CPU/GPU benchmarking is a separate iteration after correctness lands.
cros-codecs Rust replacement (per user_stance_rust.md).
Bootlin / Collabora upstreaming default-deferred (per feedback_no_upstream.md). Same discipline as libva-multiplanar.
KWin / panfrost / Mali-T860 work — orthogonal until proven otherwise; a parallel kwin-fourier-fresnel campaign would be a separate decision.

Process

8(+1) phase loop per feedback_dev_process.md. Phase 0 substrate is in phase0_findings.md. Phase 5 review uses the sonnet-architect subagent pattern (Plan with model: sonnet).

In-session-acquired data discipline per feedback_replicate_baseline_first.md: libva-multiplanar's ohm-side measurements are reference history, not threshold sources for fresnel-fourier cells.

Predecessor work this campaign builds on

../libva-multiplanar/ — five closed iterations on ohm. Read in order:
- README.md — current state, codec scope, file map.
- phase8_iteration5_close.md — most recent close. The iter5-end backend is the substrate fresnel-fourier starts from.
- phase0_findings.md (and phase0_findings_iter[2-5].md) — locked-scope precedent for codec breadth and consumer matrix on ohm; useful frame-of-reference when locking fresnel-side scope.
- phase8_iteration1_close.md — iter1 surface-export DMA-BUF lifecycle race + multi-resolution cache + 64-pitch alignment bugs. Likely re-surface candidates on RK3399.
../libva-multiplanar/libva-v4l2-request-fourier/ — the fork itself. 12 commits ahead of bootlin tip plus iter1..iter5 work. git log for the actual landing record.
~/.claude/plans/dynamic-forging-piglet.md — fresnel SDDM greeter crash diagnosis + recovery plan. Phase 0 task 1 picks up from here.
~/src/fourier_attribution/ — ohm-only attribution matrix. The chromium-fourier WHEAT-but-fragile verdict and Cell E (vanilla Chromium 149 control) item are ohm-side context, not fresnel data.

External reference (carry-over from libva-multiplanar):

Mozilla bug 1833354 / 1965646 (Firefox HW decode on RK35xx via libva-v4l2-request).
Bootlin upstream bootlin/libva-v4l2-request — dormant since 2021.
Linux kernel drivers/staging/media/rkvdec/ — RK3399 rkvdec H.264/HEVC/VP9 control protocol reference.
Linux kernel drivers/media/platform/verisilicon/hantro_* — RK3399-vpu-dec MPEG-2/H.264/VP8 control protocol reference.

Repository layout

~/src/fresnel-fourier/                     <- this campaign (its own git repo)
├── README.md                              <- this file
├── phase0_findings.md                     <- locked research question + Phase 0 work list
├── (worklist.md, phase[2-8]*.md as phases land)
└── (the libva fork is NOT here — see ../libva-multiplanar/libva-v4l2-request-fourier/)

The campaign repo and the fork repo stay separate. fresnel-fourier commits its findings here; code changes to the backend land on the fork's master (or a branch named per the iteration if scope diverges from libva-multiplanar's ohm-side master).

Operator-facing repo URL: git.reauktion.de/marfrit/fresnel-fourier — created empty during scaffolding, no push until first iteration finds something worth publishing.

Non-upstreaming default

Inherited from libva-multiplanar / feedback_no_upstream.md. Patches must be aligned to upstream in syntax and semantics; PR/MR/bug-report only on explicit operator instruction.

Build infrastructure

distcc/cross-build path is the existing fleet: aarch64crosscompiler LXD on data, tesla LXD on hertz, dcc1 on dcw3. See reference_distcc_kernel_builds.md for invocation. Per the locked Phase 0 answer for libva-multiplanar (item 9), no distcc for libva builds — libva is small and links fast, hand-build on fresnel directly. Same default applies here unless a specific reason emerges.

For chromium-fourier 149 / firefox-fourier rebuilds against fresnel-side findings, the boltzmann LXD container path from libva-multiplanar iter3 is reusable.

README.md Unescape Escape

fresnel-fourier

TL;DR

Origin

Hardware target

Scope (LOCKED 2026-05-07 in phase0_findings.md)

Process

Predecessor work this campaign builds on

Repository layout

Non-upstreaming default

Build infrastructure

README.md