VP9 (vp9.c:624) and MPEG-2 (mpeg2.c:150,156) use v4l2_timeval_to_ns
identically to H.264. Both PASS via libva with the same gettimeofday-
based giant ns values. If timestamp magnitude were the bug, VP9/MPEG-2
should also fail. They don't.
Reviewer flagged α-7 as low-probability fix and pointed to iter10
kernel-side investigation (M-A vb2_find_buffer_by_timestamp overflow)
if α-7 confirmed inert.
IMP-1: timestamp_counter should live in object_context not driver_data
to avoid multi-context collisions.
Decision: implement α-7 anyway as empirical confirmation (5 min) since
test cost is trivial. If α-7 fails as predicted, iter9 closes PARTIAL
with wire-byte search exhausted; iter10 candidates pivot to slice-data
encoding or kernel investigation.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
