iter2 Phase 3: baselines — substrate verified post-upgrade, HEVC anchor captured
Phase 3 baselines for iter2 HEVC. Substrate-update verification
ran first (post pacman -Syu rolling upgrade), then iter2-specific
HEVC cross-validator anchor + Bug 1 scratch.
Pre-Phase-3 substrate event: pacman -Syu landed 71 packages.
The "scheduled for linux-7" upgrade was headers-only —
linux-eos-arm-headers 6.19.9-99 → 7.0.3-1, but linux-eos-arm
kernel binary stayed at 6.19.9-99 (EOS-ARM repo hasn't
published the matching 7.x kernel yet). Userland refreshed:
qt6-base epoch bump, libdrm 2.4.131 → 2.4.133, chromium
147 → 148, KDE 26.04.1 batch, mkinitcpio 41-3, etc. OC DTB
intact (sha256 unchanged). mfritsche Plasma session active
throughout, no SDDM regression on this kernel boot.
eos-reboot-recommended marker installed; reboot deferred.
Baseline A (substrate validation post-upgrade):
T4 H.264 +30s and iter1 MPEG-2 +02s reference hashes all
8 match exactly:
H.264 HW1=SW1=f623d5f7a41697f67dd227275c6f1b21ffc257f65626d32fde8229357f8764c9
H.264 HW2=SW2=7d7bc6f2146dda8b2d223bba622c4b9fbe9674181ff1e02afe286b620342e0a8
MPEG-2 HW1=SW1=6e7873030dbf0403c67f35dd106ebef3c7909a0fd12433b82ad758e7fee9f092
MPEG-2 HW2=SW2=ccc7ce08810d4a96e9ba7a19f4f95bbf6cc861bda9337604b5c668ad52bef7de
Userland upgrade did not regress kernel-side decode or
DMA-BUF GL readback.
Baseline B (HEVC cross-validator verbatim contract anchor):
ffmpeg -hwaccel v4l2request decoded bbb_720p10s_hevc.mp4
-frames:v 5 cleanly. Per-frame submission shape:
VIDIOC_S_EXT_CTRLS, ctrl_class=V4L2_CTRL_CLASS_CODEC_STATELESS,
count=5
0xa40a90 SPS size=40
0xa40a91 PPS size=64
0xa40a92 SLICE_PARAMS size=N (dynamic-array)
0xa40a93 SCALING_MATRIX size=M
0xa40a94 DECODE_PARAMS size=328
Plus init device-wide:
0xa40a95 DECODE_MODE (menu, set once)
0xa40a96 START_CODE (menu, set once)
Key Phase 2 amendments from Phase 3 evidence:
- Per-frame batch is 5 controls (not "up to 6" — BBB
doesn't trigger ENTRY_POINT_OFFSETS / EXT_SPS_*).
- SCALING_MATRIX is sent unconditionally for BBB. FFmpeg
gates on ctx->has_scaling_matrix from kernel
VIDIOC_QUERY_EXT_CTRL at init, NOT on per-frame
bitstream flags. Phase 4 plan amends: query kernel for
SCALING_MATRIX availability at init, submit if available.
SPS payload field-decoded (40 bytes verbatim from BBB
fixture): 1280x720, 8-bit, 4:2:0, no PCM, flags = SAO |
STRONG_INTRA_SMOOTHING. PPS + DECODE_PARAMS + SLICE_PARAMS +
SCALING_MATRIX payloads captured for Phase 4 transcription.
Baseline C (slice-count probe): deferred. ffprobe confirms
1 video stream HEVC Main 1280x720 24fps 10s. Per-frame
slice-count not directly extracted; assume 1 slice/frame for
x265 ultrafast preset until Phase 6 verifies. Kernel
advertises slice_params dynamic-array max 600 entries
(phase0 v4l2_inventory), so multi-slice frames are supported
by the contract.
Baseline D (Bug 1 scratch test, collateral safety):
Applied Bug 1 (config.c break for HEVCMain) on throwaway
branch; h265.c stayed disabled. Built + installed.
H.264 HW frames @ +30s: f623d5f7..., 7d7bc6f2... (match T4)
MPEG-2 HW frames @ +02s: 6e7873030dbf..., ccc7ce08810d...
(match iter1)
Bug 1 in isolation does not regress H.264 or MPEG-2.
HEVC behavior with Bug 1 only:
libva trace: vaCreateConfig SUCCESS for VAProfileHEVCMain
ffmpeg: Task finished with error code: -5 (Input/output error)
Decode fails downstream because picture.c:204-206 still has
the explicit case VAProfileHEVCMain: return UNSUPPORTED_PROFILE
reject (Bug 2). Confirms Phase 2 prediction; Bug 2 fix
requires h265_set_controls to exist (Bug 3-6: enable +
rewrite). Bug 2 lands together with the h265.c rewrite in
Commit B (analogous to iter1 Commit B).
Scratch state cleaned: git checkout + rebuild + reinstall
master backend. H.264 + MPEG-2 still pass. Back to Baseline-A-
equivalent state.
Phase 4 plan inputs updated:
- Per-frame batch: 5 controls (not "up to 6")
- SCALING_MATRIX: unconditional iff kernel advertises (init
QUERY_EXT_CTRL probe), not bitstream-conditional
- SLICE_PARAMS: dynamic-array (max 600 elems per kernel UAPI)
- DECODE_MODE + START_CODE: 2 device-wide menus at init
- Phase 7 harness anchors on mpv-vaapi-vo=image (DMA-BUF GL
cache-coherency-safe path per
feedback_rockchip_pixel_verify_path.md)
- Phase 7 bonus: byte-compare post-fix S_EXT_CTRLS payload
against Baseline B (per feedback_review_empirical_over_
theoretical.md — empirical wins)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
claude-noether
d35a247948