iter1 Phase 7: verification — all 5 criteria GREEN, second codec PASS

Phase 7 verification of iter1 MPEG-2 fix executed against fork tip
229d6d1 (libva-v4l2-request-fourier master = post-Commit-D).
Verbatim raw output captured to phase0_evidence/2026-05-08/
iter1_phase7/. All five Phase 1 criteria green; bonus byte-compare
confirms structural match against Baseline C with one numerical
divergence (vbv_buffer_size, kernel-ignored, non-blocking).

Phase 1 → Phase 7 scoreboard:

  Criterion 1 (vainfo MPEG-2 Simple+Main enum):           PASS
  Criterion 2 (vaCreateConfig SUCCESS for MPEG2Main):     PASS
    Pre-iter1: VA_STATUS_ERROR_UNSUPPORTED_PROFILE (12)
    Post-iter1: VA_STATUS_SUCCESS (verified verbatim libva trace)
  Criterion 3 (ffmpeg-hwaccel-vaapi engages backend):     PASS
    5 frames decoded, exit 0, no Failed-to-create lines,
    no S_EXT_CTRLS EINVAL on the MPEG-2 path
  Criterion 4 (DMA-BUF GL HW=SW byte-identical at +02s):  PASS
    HW frame 1: 6e7873030dbf0403c67f35dd106ebef3c7909a0fd12433b82ad758e7fee9f092
    SW frame 1: 6e7873030dbf0403c67f35dd106ebef3c7909a0fd12433b82ad758e7fee9f092
    HW frame 2: ccc7ce08810d4a96e9ba7a19f4f95bbf6cc861bda9337604b5c668ad52bef7de
    SW frame 2: ccc7ce08810d4a96e9ba7a19f4f95bbf6cc861bda9337604b5c668ad52bef7de
    Frames 1 vs 2 differ in size (real motion).
  Criterion 5 (T4 H.264 reference hashes match):          PASS
    HW + SW frames at +30s into bbb_1080p30_h264.mp4 match
    f623d5f7... and 7d7bc6f2... exactly. No H.264 regression.

Bonus byte-compare against Phase 3 Baseline C verbatim:

  count=3, ctrl_class=V4L2_CTRL_CLASS_CODEC_STATELESS=0xf010000:
    SEQUENCE     id=0xa409dc size=12   (matches)
    PICTURE      id=0xa409dd size=32   (matches structurally)
    QUANTISATION id=0xa409de size=256  (intra matrix bytes
                                        IDENTICAL to Baseline C
                                        verbatim 64 bytes;
                                        non_intra all 16's)
    All return = 0 (kernel accepts every batched call).

  One numerical divergence: sequence.vbv_buffer_size
    post-fix:    0x100000 = 1 048 576 (= SOURCE_SIZE_MAX)
    Baseline C:  0x151800 = 1 376 256 (= negotiated sizeimage)
    Kernel ignores per v4l2-controls.h:2003 (informational).
    Decode is bit-exact correct regardless. Phase 5 reviewer S2
    was numerically prescient; my Phase 5 response (rejected with
    "slot->size = sizeimage") was wrong empirically; operational
    impact nil. Tracked as low-priority post-iter1 polish.

Phase 7 → Phase 8: clean transition, no loopback to Phase 4.

Notable observations for Phase 8 memory update:

  1. V4L2 /dev/videoN numbering shuffles across reboots on RK3399.
     Phase 0/3 had rkvdec=video3+media1, hantro=video5+media2; this
     boot has rkvdec=video1+media0, hantro=video3+media1. Phase 1
     binding cells using fixed paths fragile across reboots. Phase
     4 cross-cutting fix candidate: backend probes /dev/media* for
     driver=hantro-vpu/rkvdec rather than env-var stability.

  2. iter1 patch-0011 cache-stale bug class also affects MPEG-2
     (verified empirically; same as H.264 in T4). vaDeriveImage
     readback returns all-zero NV12 via ffmpeg-vaapi+hwdownload.
     Workaround: DMA-BUF GL import (mpv --vo=image) is cache-
     coherency-safe. Phase 4 cross-cutting fix candidate: add
     VIDIOC_EXPBUF + DMA_BUF_IOCTL_SYNC support to libva backend
     image-export path.

  3. src/context.c:142-155 H.264 device-init logs noisy EINVAL on
     hantro every CreateContext (return value cast to (void) but
     v4l2.c:484 still calls request_log). Cosmetic suppression
     candidate; low priority.

  4. Phase 6 commit D (fix-forward for missed mpeg2-ctrls.h
     include in context.c) — Phase 2 grep audit was incomplete.
     Phase 8 lesson: when deleting a header, completeness check
     is git rm + clean rebuild, not grep alone.

Campaign scoreboard: 1/5 → 2/5 codecs passing
(H.264 in T4, MPEG-2 in iter1). Iter1 advances to Phase 8.

Refs:
  ../libva-v4l2-request-fourier@229d6d1 (the fork tip verified)
  phase4_iter1_plan.md (criteria as locked, including Phase 5
                        amendments to criterion 3 + criterion 4)
  phase5_iter1_review.md (S2 partial-correct; S3, Q4, Q5
                          confirmed empirically)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

phase0_evidence/2026-05-08/iter1_phase7/criterion2_3/ffmpeg.stdout

@@ -0,0 +1,22 @@
+Input #0, mpegts, from '/home/mfritsche/fourier-test/bbb_720p10s_mpeg2.ts':
+  Duration: 00:00:10.00, start: 1.441667, bitrate: 4202 kb/s
+  Program 1 
+    Metadata:
+      service_name    : Service01
+      service_provider: FFmpeg
+  Stream #0:0[0x100]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], 24 fps, 24 tbr, 90k tbn, start 1.441667
+    Side data:
+      CPB properties: bitrate max/min/avg: 0/0/0 buffer size: 1130496 vbv_delay: N/A
+Stream mapping:
+  Stream #0:0 -> #0:0 (mpeg2video (native) -> wrapped_avframe (native))
+Press [q] to stop, [?] for help
+v4l2-request: cap_pool_init: 24 slots ready (v4l2_index=0..23, 1 plane(s) per slot)
+v4l2-request: Unable to set control(s): Invalid argument
+Output #0, null, to 'pipe:':
+  Metadata:
+    encoder         : Lavf62.12.100
+  Stream #0:0: Video: wrapped_avframe, nv12(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 24 fps, 24 tbn
+    Metadata:
+      encoder         : Lavc62.28.100 wrapped_avframe
+[out#0/null @ 0xaaaabf90c500] video:2KiB audio:0KiB subtitle:0KiB other streams:0KiB global headers:0KiB muxing overhead: unknown
+frame=    5 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.20 bitrate=N/A speed=1.46x elapsed=0:00:00.14