ampere-fourier

2 Commits 1 Branch 0 Tags

Author	SHA1	Message	Date
marfrit	0d9914062c	iter1 phase1: goal formulation Locks iter1 scope to the 3 currently-kernel-supported codecs (H.264, VP8, MPEG-2). The other 3 (HEVC, VP9, AV1) are deferred to dedicated iter2/3/4 loops — bundling them would conflate three different external dependencies into one un-closable iteration. Resolves Phase 0 open questions Q1 (scope = 3 codecs), Q2 (bit-exact anchor = libva-HW vs SW byte-compare; kdirect-on-RK3588 is its own piece of work), Q4 (firefox-fourier in scope as consumer test). Defers Q3 (HEVC OOPS sandboxing) and Q5 (AV1 source clip) to the relevant iterations. Success criteria are six per-codec instruments (C1-C6: frame count, HW engagement via lsof+strace, byte-identical at frame 0, SSIM>=0.99 at frame 30s, N=3 FPS, clean dmesg) plus one campaign-level firefox-fourier vendor-default test (C7). Hypothesis is falsifiable in three named ways (codec crash/hang, first-frame byte deviation indicating kernel ABI drift, MPEG-2 IDCT tolerance refinement) — each maps to a specific phase loopback. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>	2026-05-16 07:20:23 +00:00
marfrit	de0f267d05	iter1 phase0: substrate / motivation / inventory Locks the research question, captures hardware + kernel + userland state, walks the V4L2 decoder topology (3 decoder cores), enumerates libva backend behavior, anchors the in-session N=1 baseline (H.264 via rkvdec, VP8 + MPEG-2 via hantro — all decode end-to-end), and documents the three blockers (kernel HEVC OOPS in rkvdec_hevc_prepare_hw_st_rps; kernel VP9 not exposed on RK3588 rkvdec; libva backend iter38 hard-capped at 2 fds, AV1 unprobed). Predecessor carryover rules followed: backend source pin + memory entries carry; per-codec FPS numbers and bit-exact criteria do not. Open questions tabled for Phase 1 goal lock: 1. Success-metric scope: 3 / 5 / 6 codecs. 2. RK3588 bit-exact anchor (kdirect adapt vs SW byte-compare). 3. HEVC OOPS pre-decode vs post-decode (instrumentation Q). 4. firefox-fourier vendor defaults adequacy on RK3588. 5. AV1 source clip provenance for the eventual iter39 test. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>	2026-05-16 07:19:57 +00:00

Author

SHA1

Message

Date

marfrit

0d9914062c

iter1 phase1: goal formulation

Locks iter1 scope to the 3 currently-kernel-supported codecs (H.264,
VP8, MPEG-2). The other 3 (HEVC, VP9, AV1) are deferred to dedicated
iter2/3/4 loops — bundling them would conflate three different
external dependencies into one un-closable iteration.

Resolves Phase 0 open questions Q1 (scope = 3 codecs), Q2 (bit-exact
anchor = libva-HW vs SW byte-compare; kdirect-on-RK3588 is its own
piece of work), Q4 (firefox-fourier in scope as consumer test).
Defers Q3 (HEVC OOPS sandboxing) and Q5 (AV1 source clip) to the
relevant iterations.

Success criteria are six per-codec instruments (C1-C6: frame count,
HW engagement via lsof+strace, byte-identical at frame 0, SSIM>=0.99
at frame 30s, N=3 FPS, clean dmesg) plus one campaign-level
firefox-fourier vendor-default test (C7).

Hypothesis is falsifiable in three named ways (codec crash/hang,
first-frame byte deviation indicating kernel ABI drift, MPEG-2 IDCT
tolerance refinement) — each maps to a specific phase loopback.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

2026-05-16 07:20:23 +00:00

marfrit

de0f267d05

iter1 phase0: substrate / motivation / inventory

Locks the research question, captures hardware + kernel + userland
state, walks the V4L2 decoder topology (3 decoder cores), enumerates
libva backend behavior, anchors the in-session N=1 baseline (H.264
via rkvdec, VP8 + MPEG-2 via hantro — all decode end-to-end), and
documents the three blockers (kernel HEVC OOPS in
rkvdec_hevc_prepare_hw_st_rps; kernel VP9 not exposed on RK3588
rkvdec; libva backend iter38 hard-capped at 2 fds, AV1 unprobed).

Predecessor carryover rules followed: backend source pin + memory
entries carry; per-codec FPS numbers and bit-exact criteria do not.

Open questions tabled for Phase 1 goal lock:
  1. Success-metric scope: 3 / 5 / 6 codecs.
  2. RK3588 bit-exact anchor (kdirect adapt vs SW byte-compare).
  3. HEVC OOPS pre-decode vs post-decode (instrumentation Q).
  4. firefox-fourier vendor defaults adequacy on RK3588.
  5. AV1 source clip provenance for the eventual iter39 test.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

2026-05-16 07:19:57 +00:00