test(producer): add hdr-regression and hdr-hlg-regression test suites

[vanceingalls]

Summary

Replace the trivial hdr-pq and hdr-image-only tests with two consolidated, time-windowed regression suites that exercise the full HDR pipeline. These goldens are the safety net for every other PR in this stack.

Why

The pre-existing HDR tests covered only a single full-bleed video or image with a static text label — none of the features that the HDR pipeline has to handle differently from SDR (opacity animation, z-ordered multi-layer compositing, transforms, border-radius clipping, shader transitions, multiple HDR sources, object-fit modes, mixed HDR+SDR layering, HLG transfer). This PR builds the missing safety net first so every subsequent fix can be proven correct.

What changed

• New packages/producer/tests/hdr-regression/ (PQ, BT.2020, ~20 s, 1080p, 8 windows A–H):
  • A: static baseline (HDR video + DOM overlay)
  • B: wrapper-opacity fade
  • C: direct-on-<video> opacity tween (documents the Chunk 1 bug)
  • D: z-order sandwich (DOM → HDR → DOM)
  • E: two HDR videos side-by-side (pins PR feat(hdr): z-ordered multi-layer compositing with PQ support #289)
  • F: rotation + scale + border-radius (documents the Chunk 4 bug)
  • G: object-fit: contain
  • H: shader crossfade between HDR video and HDR image
• New packages/producer/tests/hdr-hlg-regression/ (HLG, ARIB STD-B67, ~5 s, 2 windows A–B) — exercises the separate HLG LUT/OETF code path that previously had zero coverage.
• New scripts/generate-hdr-photo-pq.py synthesizes hdr-photo-pq.png with a cICP chunk for BT.2020/PQ/full.
• Removed tests/hdr-pq/ and tests/hdr-image-only/.
• Updated .github/workflows/regression.yml HDR shard to run the new pair sequentially.
• All compositions follow the documented timed-element pattern (data-start, data-duration, class="clip" directly on each timed leaf — no wrapper inheritance).

Test plan

• Goldens generated with bun run test:update --sequential.
• ffprobe confirms HEVC/yuv420p10le/bt2020nc/smpte2084 (PQ) and arib-std-b67 (HLG).
• Suite green with maxFrameFailures budgets that absorb the documented Chunk 1 / Chunk 4 known-fails — tightened in follow-up PRs in this stack.

Stack

Foundational PR for the HDR follow-ups stack (Chunk 0 of plans/hdr-followups.md). Every subsequent PR builds on this safety net.

[vanceingalls]

• docs(engine): document __name polyfill and add regression test #385
• perf(producer): cache transfer-converted hdr image buffers per render job #384
• perf(producer): gate per-frame debug meta via optional isLevelEnabled #383
• perf(producer): hdr benchmark harness — --tags filter, peak heap/RSS tracking, bench:hdr script #382
• test(producer): extract frameDirMaxIndexCache to its own module and pin cross-job isolation #381
• test(engine): cover spawnStreamingEncoder lifecycle and cleanup paths #380
• test(engine): add ffprobe-unavailable fallback regression tests #379
• test(shader-transitions): add midpoint (p=0.5) regression invariants for all shaders #378
• test(engine): lock down sRGB→BT.2020 LUT with byte-exact reference values #377
• build(lfs): track tests/*/src/*.png via Git LFS #376
• test(hdr-regression): tighten Window F maxFrameFailures budget after Chunk 4 fix #375
• fix(engine,shader): handle matrix3d transforms and hide non-first scenes #374
• refactor(producer): extract HDR compositing helpers and rename media metadata #373
• fix(producer): wire --crf and --video-bitrate CLI overrides into encoders #372
• fix(producer): tighten resource lifecycle and harden file server #371
• feat(engine): wire options.hdr through chunkEncoder + dynamic SDR→HDR transfer #370
• test(hdr-regression): tighten Window C maxFrameFailures budget after Chunk 1 fix #369
• fix(engine): stop clobbering native <video> opacity in HDR pipeline #368
• refactor(shader-transitions): extract DEFAULT_DURATION and DEFAULT_EASE constants #367
• refactor(types): tighten type safety, dedupe HfTransitionMeta, prune dead LUT export #366
• test(producer): add hdr-regression and hdr-hlg-regression test suites #365 👈 (View in Graphite)
• main

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[jrusso1020]

Foundational correctness for the stack — every PR after this one leans on these goldens to prove its fix is real. Test design is the right shape:

• Eight PQ windows each exercise an orthogonal code path the old hdr-pq fixture never touched (wrapper-opacity, direct-<video>-opacity, z-order sandwich, multi-HDR, transform+radius, object-fit, shader transition).
• Splitting the HLG suite out as hdr-hlg-regression (2 windows) is the right call — HLG's OETF and LUT live on a separate code path from PQ, and lumping them into one suite would mask HLG regressions under PQ dominance.
• Windows C and F are deliberately set up as documented known-fails with wide maxFrameFailures budgets, tightened in follow-up PRs in this stack (#369 for C, #375 for F). That's the right pattern for landing safety nets before fixes — the fix PR tightens the budget, which mechanically proves the fix.

The regression-suite contract in the README (HDR frames reach the encoder in RGB48 BT.2020 10-bit without sRGB→BT.709 round-tripping, opacity respected on timed leaves, transforms don't clobber the HDR layer's pixel buffer) is the right set of invariants to pin.

Two non-blocking observations:

1. scripts/generate-hdr-photo-pq.py should live somewhere discoverable for future contributors. Right now it's tucked under tests/hdr-regression/scripts/ which is fine, but a one-line README.md note on "to regenerate, run python scripts/generate-hdr-photo-pq.py" is worth it so the synthesized golden doesn't become a black box.
2. maxFrameFailures budget values for the not-known-fail windows would benefit from a brief comment on where the tolerance came from (e.g. "allows up to N frame diffs from codec noise"). Without it, a future contributor tightening budgets can't tell what room is real and what's codec-jitter slack.

CI shows one failure on styles-a — unrelated to the new suites (different test shard), likely a pre-existing flake on master.

Approved.

— Rames Jusso

[vanceingalls]

Both observations addressed in 75c6afa:

1. generate-hdr-photo-pq.py discoverability — hdr-regression/README.md now points at the script in the regeneration block (lines 22-26), so it's not a black box anymore.
2. maxFrameFailures budget rationale — hdr-hlg-regression/README.md got the new Tolerance section (maxFrameFailures: 0, with the reasoning that HLG is a pure pass-through and rgb48le → HEVC is byte-deterministic, so any drift is a real regression). For the PQ suite, the same commit also collapsed the README from 8 windows down to 4 (A–D) after test(hdr-regression): tighten Window C maxFrameFailures budget after Chunk 1 fix #369 (window C re-baselined) and test(hdr-regression): tighten Window F maxFrameFailures budget after Chunk 4 fix #375 (window F fixed) landed; the budget table I'd intended for the PQ side got dropped in that simplification. Current maxFrameFailures: 30 on the PQ suite is now under-documented — happy to add a follow-up commit to put the budget breakdown back if you'd like, but flagging it candidly here rather than back-justifying a number.

Thanks for the review.