Three review findings on the win32 drawElement PR:
1. gpu_renderer shipped the raw UNMASKED_RENDERER_WEBGL string — unbounded,
driver-authored, GPU-model-specific, and |-joined across parallel
sessions, i.e. high cardinality by construction, against this file's own
convention of sanitizing engine-sourced strings (deGateReason is a
bucket; error messages go through redactTelemetryString). Now bucketed at
the source by classifyGpuRenderer to <backend>/<vendor>
(metal/apple, d3d11/nvidia, swiftshader/other, ...), which is the whole
analytic signal the win32 rollout needs and nothing else. The raw string
never leaves the engine.
2. gpu_renderer reached render_complete only, so a crashed render — the
cohort the field exists to attribute — carried no backend. It now rides
RenderCaptureObservability (deGpuRenderer, sourced from the live probe
session like the de_* counters), so both render_complete and
render_error carry it and a hard failure still reports its GPU backend.
On render_complete the perfSummary value still wins by spread order.
3. Restore the fallow-ignore-next-line suppression above
__resetDeParallelRouterTrialStateForTests: CLI test files are not fallow
entry points, so removing it fails the CI dead-code audit (local
pre-commit passed only because of its changed-file scope).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Widen the default-on drawElement clamp from darwin-only to darwin|win32
(still requiring a non-software-GPU browser). The darwin restriction was a
validation envelope, not an architectural limit — the CanvasDrawElement
Chrome flag ships on every platform, and every safety layer that made the
macOS default-on release (v0.7.38) survivable is platform-neutral:
compile-time gates, the SwiftShader init gate, per-render worker-encode
self-verification with screenshot fallback, and the blank guard. Worst case
on an unvalidated D3D11 backend is the same as on Metal: verify catches a
bad frame and the render re-runs on the screenshot baseline.
Why now: 30-day telemetry shows ~206k non-CI hardware-GPU Windows renders
(~78% of the win32 fleet, 18k installs) held on the slow screenshot path by
the clamp — the second-largest perf population after macOS, carrying ~1,550
capture-hours/month in the DE-eligible >=700-frame band alone at a measured
~2x speedup opportunity.
Instrumentation for the new cohort: drawElement session init now records the
raw WebGL UNMASKED_RENDERER_WEBGL string (detectSwiftShader generalized to
detectGpuBackend — same single evaluate, the string was previously read and
discarded) and threads it session -> CapturePerfSummary -> RenderPerfSummary
-> render_complete as `gpu_renderer`. drawElement damage proved
compositor-backend-specific throughout the macOS rollout, so D3D11-cohort
failures must cluster by ANGLE backend + GPU vendor (NVIDIA/AMD/Intel), not
just `os`.
The two DE clamp branches are extracted into a pure, unit-tested
`resolveDefaultDrawElement` (platform + GPU mode + worker-encode + explicit
opt-in), which also drops resolveConfig's cyclomatic complexity. The win32
streaming-encode compound tests collapse onto one shared helper.
Linux stays excluded: that fleet is headless/Docker SwiftShader, where DE
has no speedup and known rendering defects. Kill switches unchanged:
PRODUCER_EXPERIMENTAL_FAST_CAPTURE=false, --experimental-fast-capture=false.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
* fix(producer): accept partial color metadata in plan v2
* test(engine): make partial color probe hermetic
* fix(producer): validate plan v2 sentinels in fallback mode
Linear: VA-1859
## Problem
For a `fit_to_scene` B-roll where the composition's intrinsic timeline (e.g. `data-duration=1.0s` → 30 frames) is shorter than the scene it fills (e.g. 4.8s narration), the producer renders only the intrinsic 30 frames and the downstream compositor frame-holds/PTS-stretches that fixed clip to the scene length. Spreading 30 unique frames over 4.8s starves motion to ~6 effective fps → a visibly choppy result. Root cause: the producer welds one `composition.duration` to both the frame count and the 1:1 seek mapping, with no notion of a target output length.
## Fix
Add optional `renderStretch: number` (default `1.0` = no-op), `renderStretch = intrinsic / target`:
- **Frame count** comes from the target: `outputDuration = intrinsic / renderStretch`, `totalFrames = outputDuration × fps` (`probeStage.ts`). `composition.duration` stays intrinsic (drives video/audio windows).
- **Per-frame seek** is scaled: `time = (frameIndex / fps) × renderStretch`, so the N output frames map across `[0, intrinsic]` — a fresh frame per output frame.
All seek sites go through a single shared `outputFrameToTimelineSeconds(frameIndex, fps, renderStretch)` helper (`core.types.ts`), consumed by every capture path so none can silently diverge:
- parallel (`parallelCoordinator.ts`), `sdr_streaming` (`captureStreamingStage.ts` ×3), `sdr_disk` (`captureStage.ts`), HDR loops.
- DrawElement + static self-verify (`frameCapture.ts`) — ground-truth seek uses the same mapping, so PSNR compares like-for-like (no spurious verification failure on stretched comps).
- Distributed path: `renderStretch` threaded through `DistributedRenderConfig` → chunk workers, and **folded into the plan hash only when `!= 1`** so a pre-stretch cached plan is never reused.
With `renderStretch = 1` (or omitted → `?? 1`): every seek is `×1.0` (IEEE-754 identity), frame counts unchanged, and the plan hash is byte-identical — a provable no-op. `player.ts` absolute-seek is untouched.
## Verify
- typecheck (core + engine + producer): pass. lint/format/fallow/commitlint: pass. `planHash` + `renderRequest` unit suites: pass.
- Adversarial self-review found + fixed three capture-path gaps (streaming, self-verify, distributed) before this revision.
- **Not yet runtime-verified** on a real render — needs a fit_to_scene render at `renderStretch < 1` confirming N distinct frames over the target length (draft until then).
Paired with experiment-framework#42766, which computes and forwards `renderStretch = hf intrinsic / scene duration`.
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