iter2 Phase 7: verification — all 5 criteria GREEN, third codec PASS
Phase 7 verification of iter2 HEVC fix executed against fork tip
8d71e20 (libva-v4l2-request-fourier master = post-iter2-Commit-B).
Verbatim raw output captured to phase0_evidence/2026-05-08/
iter2_phase7/. All five Phase 1 criteria green; bonus byte-compare
confirms structural match against Baseline B with two minor field-
value divergences (informational SPS fields VAAPI doesn't expose;
non-blocking per Criterion 4 byte-identical pixel pass).
Phase 1 → Phase 7 scoreboard:
Criterion 1 (vainfo VAProfileHEVCMain enum): PASS
rkvdec bind: H.264 (5 profiles) + HEVCMain — same as Baseline.
Criterion 2 (vaCreateConfig SUCCESS for HEVCMain): PASS
Pre-iter2: VA_STATUS_ERROR_UNSUPPORTED_PROFILE (12)
Post-iter2: VA_STATUS_SUCCESS (verified verbatim libva trace)
Criterion 3 (ffmpeg-direct HEVC engages backend, exit 0): PASS
5 frames decoded clean, cap_pool_init: 24 slots ready,
no Failed-to-create lines, no S_EXT_CTRLS EINVAL.
Criterion 4 (DMA-BUF GL HEVC HW=SW byte-identical at +02s): PASS
HW frame 1: 47a5f3850df5d8c732767a227830c2272ff78402a7b6adeea329e29838808be5
SW frame 1: 47a5f3850df5d8c732767a227830c2272ff78402a7b6adeea329e29838808be5
HW frame 2: a467b3bc9d7b6374b6786ecfac46932d6c7bb932ab11d311edaa233d7863e656
SW frame 2: a467b3bc9d7b6374b6786ecfac46932d6c7bb932ab11d311edaa233d7863e656
Frames 1 vs 2 hash-differ (real motion).
Criterion 5 (iter1 MPEG-2 + T4 H.264 reference hashes): PASS
H.264 +30s HW1: f623d5f7a41697f67dd227275c6f1b21ffc257f65626d32fde8229357f8764c9 (T4 ref MATCH)
H.264 +30s HW2: 7d7bc6f2146dda8b2d223bba622c4b9fbe9674181ff1e02afe286b620342e0a8 (T4 ref MATCH)
MPEG-2 +02s HW1: 6e7873030dbf0403c67f35dd106ebef3c7909a0fd12433b82ad758e7fee9f092 (iter1 ref MATCH)
MPEG-2 +02s HW2: ccc7ce08810d4a96e9ba7a19f4f95bbf6cc861bda9337604b5c668ad52bef7de (iter1 ref MATCH)
Bonus byte-compare against Phase 3 Baseline B verbatim:
count=5, ctrl_class=V4L2_CTRL_CLASS_CODEC_STATELESS=0xf010000:
SPS id=0xa40a90 size=40 (matches Baseline B)
PPS id=0xa40a91 size=64 (matches)
SLICE_PARAMS id=0xa40a92 size=280 (1 slice × sizeof(slice_params))
SCALING_MATRIX id=0xa40a93 size=1000 (matches sizeof(scaling_matrix);
Phase 4 plan typo'\''d 1296 — actual
struct sums to 1000 = 96+384+384+
128+6+2)
DECODE_PARAMS id=0xa40a94 size=328 (matches)
All return = 0 (kernel accepts every batched call).
SPS field-value divergences vs Baseline B (FFmpeg-v4l2request):
sps_max_num_reorder_pics: post-fix=0 baseline=2 DIVERGE
sps_max_latency_increase_plus1: post-fix=0 baseline=4 DIVERGE
All other SPS fields match (pic_width=1280, pic_height=720,
bit_depth=0, flags=0x180=SAO|STRONG_INTRA_SMOOTHING).
PPS flags also diverge slightly (bit 12 ENTROPY_CODING_SYNC_ENABLED:
post-fix unset, baseline set). Other PPS fields match.
Cause: VAAPI'\''s VAPictureParameterBufferHEVC doesn'\''t expose
sps_max_num_reorder_pics, sps_max_latency_increase_plus1, or
always-truthful entropy_coding_sync. FFmpeg parses these from
bitstream directly. Operational impact NIL (Criterion 4 byte-
identical pixel pass — kernel decoded correctly with these fields
defaulted to 0). Phase 8 polish backlog candidate (low priority):
add SPS bitstream parsing to extract these fields when VAAPI
doesn'\''t supply them.
Phase 7 → Phase 8: clean transition, no loopback.
Notable Phase 7 observations for Phase 8 memory:
1. Phase 5 review value confirmed: 3 Critical findings (C1
data_byte_offset rename, C2 dpb.rps→index-arrays semantics,
C3 pic_order_cnt_val rename) caught at Phase 5 — prevented
Phase 6 compile failures + at least 1-2 Phase 7→Phase 4
loopback cycles. Per memory feedback_review_empirical_over_
theoretical.md: every Critical/Should-fix verified
empirically before responding. Lesson held.
2. One Phase 5 amendment was empirically wrong: S1 suggested
uniform_spacing_flag exists in VAAPI; gcc test-compile rejected.
Both PPS bits 19+20 left zero (VAAPI exposes neither).
Documented inline. Lesson: even reviewer-cited field mappings
warrant empirical verification.
3. Phase 4 plan typo: claimed sizeof(scaling_matrix) = 1296;
empirical size is 1000. Code uses sizeof() so produces correct
bytes. Plan body amendment-by-side-channel; not blocking.
4. VAAPI↔V4L2 field-fidelity gaps surfaced: 2 SPS fields +
possibly 1 PPS bit not exposed by VAAPI. Operational nil;
Phase 8 polish-backlog candidate.
5. mpv --hwdec=vaapi engages HEVC cleanly (no MPEG-2-style
filtering). Confirms Phase 5 Q3 — VAPictureParameterBufferType
sent per-frame for HEVC; latent B3 bug masked same as MPEG-2.
6. BBB HEVC fixture is 1 slice per frame (slice_params size=280
= 1 × sizeof). Multi-slice path in iter2 is coded but
untested by binding cell.
Campaign scoreboard: 2/5 → 3/5 codecs passing
(H.264 in T4, MPEG-2 in iter1, HEVC in iter2). iter2 advances
to Phase 8.
Refs:
../libva-v4l2-request-fourier@8d71e20 (the fork tip verified)
phase4_iter2_plan.md (10 contract clauses; SCALING_MATRIX size
typo noted)
phase5_iter2_review.md (3 Critical + 4 Should-fix amendments
all incorporated; S1 partially empirically
incorrect — VAAPI doesn'\''t expose
uniform_spacing_flag)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
claude-noether
05b4bd56ec