After #916 moved `assertSwiftShader` from `renderChunk()`'s eager probe
session into `executeWorkerTask`, every parallel worker began running its
own `chrome://gpu` / canvas-WebGL probe. At `chunkWorkerCount=6` (texture
launch at chunks=3) that's 6 concurrent CDP page-loads per chunk × 3
chunks = 18 simultaneous probes. Bench data on dev (12 producer pods × 22
vCPU) showed c=3 worst-case wall-clock at 67.3s, 24.7s above c=6 worst
(42.6s) — pod_total inflates 100s → 147s uniformly across all three
chunks per slow iter, the signature of cluster-level CDP contention
rather than within-pod contention.
Workers within a chunk share the same Chrome binary, flags, and OS/driver
state on a single pod, so worker 0's success is representative for the
rest. Gate the probe via `shouldVerifyWorkerGpu(workerId, config)` so
only worker 0 navigates to the probe page; workers 1..N-1 skip it. The
fail-fast contract still holds at the chunk level (worker 0 still aborts
the chunk if SwiftShader didn't load) — just without the concurrent CDP
traffic.
Expected wall-clock impact: c=3 worst drops from ~67s to in line with
c=6 worst (~42-44s). c=6 (3 workers/pod) and c=8 (2 workers/pod) should
see smaller wins; c=12 (1 worker/pod, sequential branch) is unaffected.
Closes#955.
Adds a Blocks tab to the Studio left sidebar with the full 78-item registry
catalog (58 blocks + 20 components). Users can browse by category, search by
title/description, preview CDN-hosted poster thumbnails with video-on-hover,
and install items on-demand with one click or drag-to-timeline.
Core changes:
- BlockCategory type + resolveBlockCategory() for 7 categories (Captions, VFX,
Transitions, Effects, Social, Data, Scenes)
- Registry API routes: GET /api/registry/blocks (catalog) + POST install
- StudioApiAdapter extended with listRegistryCatalog + installRegistryBlock
- Vite adapter reads from disk; CLI adapter fetches from GitHub (24h cache)
- BlockParam interface + params on 6 blocks for future parameter controls
Studio UI:
- 4th sidebar tab "Blocks" with responsive grid, category pills, search bar
- BlockCard: CDN poster thumbnail, video autoplay on hover, duration + WebGL badges
- On-demand install: blocks append as sub-compositions on timeline; components
overlay at start=0 spanning full duration with transparent background patching
- TIMELINE_BLOCK_MIME drag-and-drop to timeline
- BlockParamsPanel (Phase 3 scaffold) auto-opens for parameterized blocks
Registry manifests:
- All 58 blocks backfilled with preview: { video, poster } CDN URLs
- All 20 components normalized to object format + poster URLs added
- 6 blocks annotated with params (Liquid Glass/Background, Portal, Chart,
Logo Outro, Magnetic)
- flowchart-vertical preview generated and uploaded to CDN
Run `fallow fix --auto-fixable` to remove `export` keywords from symbols
fallow's reachability analysis identifies as unused. Keeps only the cases
where the symbol is still referenced internally in its own file (so
removing `export` doesn't surface a new oxlint `no-unused-vars` error).
Result: fallow dead-code findings drop from 276 → 208 (68 fewer unused
exports), with no behavior change — each symbol is still defined and used
exactly the same way within its file.
Reverted ~20 files where fallow's auto-fix would have created cascading
"declared but never used" lint errors — those are cases where the symbol
isn't used at all, and properly cleaning them up means deleting the
declaration, not just dropping `export`. Better to land that as a
separate, narrower PR rather than mixing it into a mechanical de-export.
Also reverted four false positives where fallow missed real consumers:
- `captureCost.ts` (renderOrchestrator has two separate import blocks
from the same module; fallow only saw the first)
- `propertyPanelHelpers.ts`, `domEditingLayers.ts` (real internal uses
fallow's reachability missed)
- `render.ts` (functions imported via `await import()` dynamic import,
which fallow's static analysis doesn't follow)
Test plan: bun run --filter '*' typecheck (clean), oxlint + oxfmt clean,
cli/core/studio/engine vitest suites pass (335 + 917 + 576 + 605 tests).
Three changes to fix regression failures without breaking baselines:
1. Revert flattenInnerRoot in producer — use the original innerHTML
inlining that preserves the existing DOM structure. Instead, set
data-hf-authored-id on the HOST element so the scoped proxy can
still rewrite #id selectors for sub-composition scripts.
2. Revert compiled.html baselines to main (no DOM structure changes).
3. Use timeline-count comparison instead of poll duration to decide
whether to call __hfForceTimelineRebind. Compare timeline count
before vs after the poll — rebind only when new timelines appeared
during polling. This correctly identifies async compositions
regardless of fetch speed, while leaving sync compositions
untouched.
1. Only call __hfForceTimelineRebind() when the timeline poll actually
had to wait (pollDuration > 2 intervals). For compositions with
synchronous timeline registration, the rebind was unnecessary and
shifted render timing, causing PSNR regressions in chat and
gsap-letters-render-compat.
2. Regenerate compiled.html baselines for missing-host-comp-id and
overlay-montage-prod to match the new flattenInnerRoot behavior
(data-composition-id stripped from inlined inner roots, replaced
with data-hf-authored-id).
3. Add late-bind polling to runtime init.ts — after external
compositions load, poll for 5s to detect async timelines that
register after initial binding (e.g. from fetch callbacks).
Review items addressed:
1. Mirror video-failure warning in beginFrame path (was screenshot-only)
2. Fix resolveProjectRelativeSrc escape-fallback to use query-stripped
cleanSrc instead of raw src for the normalize/strip arm
3. Export prepareFlattenedInnerRoot from @hyperframes/core/compiler and
consume in the producer instead of duplicating the implementation
4. Use typed Window cast instead of (window as any) for __hfForceTimelineRebind
5. Regenerate docs/public/catalog-index.json with all 6 map blocks
6. Restore Maps nav group in docs.json (catalog generator had merged
them into Data)
resolveProjectRelativeSrc now strips query parameters (e.g. ?v=4)
before joining with the project directory. Browsers ignore query
strings when loading local files, but the filesystem resolver was
looking for the literal path including the query — causing video
extraction to silently skip the file and render frozen first frames.
Previously, a missing video file (404) caused the renderer to hard-fail
after a 45-second timeout waiting for readyState >= 2. Now:
1. pollVideosReady treats errored videos (v.error set or
NETWORK_NO_SOURCE) as ready, so 404'd sources don't block
2. Screenshot mode downgrades the video timeout from a throw to a
console.warn listing affected sources, then continues rendering
3. The composition renders with the missing video as a blank area
instead of failing entirely
Two fixes for compositions that register timelines after async data
loading (e.g. fetch for TopoJSON map data):
1. engine/frameCapture: remove the hosts.length <= 1 early return
so the timeline readiness poll runs for ALL compositions, not just
multi-composition galleries. Single-composition pages with async
setup were silently skipped.
2. core/runtime/init: expose window.__hfForceTimelineRebind() which
resets childrenBound and re-runs bindRootTimelineIfAvailable().
The renderer calls this after all timelines are confirmed present,
ensuring the root player discovers late-registered timelines from
fetch callbacks.
Without these fixes, compositions using fetch() to load data at
runtime would render blank frames because the root player bound
timelines before the async setup completed, and seek() never
reached the unbound composition timeline.
The renderer now waits for all sub-composition timelines to be
registered in window.__timelines before starting frame capture.
Previously only window.__hf root readiness was checked, causing
blank frames when sub-compositions use async data loading (fetch)
or when the headless renderer starts capturing before scripts
complete.
Adds pollSubCompositionTimelines() to both screenshot and
beginFrame render paths, with a diagnostic warning listing which
composition IDs are missing if the timeout expires.
* perf(distributed): parallelize chunk capture across multiple workers
The distributed `renderChunk` primitive hardcoded `workerCount: 1` and
`captureStage` explicitly forbade `workerCount > 1` when `frameRange` was
set, with the comment:
"Distributed chunk workers fan out at the activity layer; reduce
workerCount to 1 when passing frameRange."
The assumption was that orchestration-layer fan-out (Temporal / Lambda /
K8s Jobs / SSH) saturates the available CPU on its own. In practice
adopters that deploy chunks onto multi-core hosts (8-24 vCPU is the
standard producer-worker pod sizing) end up pinning only ~3-4 cores per
chunk while the rest sit idle: chunk-level fan-out at the orchestration
layer gives each pod one chunk at a time, and the chunk render itself
was single-threaded.
Validated against a real 1080p / 30fps / 22-second shader-heavy
composition on a 22-vCPU Temporal pod: each chunk rendered at
165-273ms per frame (vs 94-98ms for the in-process streaming render
which runs `workerCount=2` by default). The slowest chunk gates total
wall-clock under parallel chunk fan-out, so the 2-3x per-frame gap
compounds and `distributed` was net-slower than `in-process` on every
composition smaller than ~5min of texture-class content. Lifting the
restriction is a measured ~2x per-chunk speedup with no contract
change at the framesDir or encoder layer.
Wire-up:
* `WorkerTask.outputFrameOffset` — optional offset subtracted from the
absolute frame index when computing the captured file's name.
Default 0 (the in-process contract; file name == absolute index).
Distributed chunks set this to the chunk's startFrame so file names
land 0-indexed within the chunk's range, matching the sequential
chunk-capture contract and the encoder's expectation that frames
are read sequentially without an `-start_number` override.
* `distributeFrames(totalFrames, workerCount, workDir, rangeStart=0)` —
offsets both `startFrame`/`endFrame` (used for per-frame time math
on the page's virtual clock) by `rangeStart`, and threads
`outputFrameOffset = rangeStart` onto each task it emits. With the
default `rangeStart=0` it is a no-op for in-process renders.
* `executeWorkerTask` — uses `i - (task.outputFrameOffset ?? 0)` for
the captured file name, leaving the per-frame TIME computation
`(i * fps.den) / fps.num` untouched so the page's virtual clock is
unchanged.
* `executeDiskCaptureWithAdaptiveRetry({ frameRangeStart? })` — accepts
the chunk's absolute startFrame and forwards it to `distributeFrames`
and `buildMissingFrameRetryBatches`. Default `undefined` preserves
the in-process contract.
* `buildMissingFrameRetryBatches(ranges, ..., rangeStart=0)` —
`findMissingFrameRanges` walks LOCAL 0-indexed file names; the retry
batch translates the local missing-range pair back to ABSOLUTE
composition indices for `WorkerTask.startFrame/endFrame` and sets
`outputFrameOffset = rangeStart` so the retried capture writes back
to the same local file name.
* `captureStage` — drops the assert; passes
`frameRangeStart: frameRange?.startFrame` to the parallel branch so
workers land on absolute composition frame indices for time math
while file names stay 0-indexed within the chunk range. Docstring
updated to reflect that the parallel branch is now supported.
* `renderChunk` — `workerCount: 1` → `workerCount: 2`. The pre-warmed
`probeSession` is consumed only by the sequential branch; the
parallel branch closes it during stage entry and creates its own
worker sessions. Documented as a follow-up: skip probeSession
creation when `workerCount > 1` to recover the ~3-5s warmup cost.
Backwards compatibility: every change is gated on a parameter that
defaults to the prior behavior. In-process callers (`executeRenderJob`)
pass no `frameRangeStart`, so `rangeStart === 0`, `outputFrameOffset`
defaults to 0, and the file-name math collapses to the prior `i` value.
The framesDir contract (`frame_0..frame_(totalFrames-1)`) and the
WorkerTask interface are extended, not replaced.
Tests: 24 pass / 0 fail across the distributed test suite (renderChunk,
plan, assemble, planFormatBanlist, planSizeCap, publicExports). 7 pass /
0 fail in `parallelCoordinator.test.ts`. The renderOrchestrator suite
has one pre-existing Windows-only failure
(`writeCompiledArtifacts — external assets on Windows drive-letter
paths`) unrelated to this change; the other 56 tests pass.
Refs: distributed-vs-inprocess benchmark thread at
heygen-com/experiment-framework#36950
* perf(distributed): auto-size chunk workerCount via calculateOptimalWorkers
Match the in-process renderer's worker selection instead of hardcoding 2.
`calculateOptimalWorkers(framesInChunk, undefined, cfg)` is the same call
`resolveRenderWorkerCount` makes under the hood, minus the capture-cost
calibration reduction (which would require plumbing the chunk's compiled
metadata through — left as a follow-up).
For a typical 22-vCPU producer-worker pod with `cfg.concurrency: "auto"`
this resolves to ~6 workers for a 240-frame chunk (capped by
`defaultSafeMaxWorkers() = max(6, min(16, floor(cpuCount/8)))`), matching
what `executeRenderJob` (the in-process path) already does. The prior
hardcoded `workerCount: 2` was a safe-minimum starting point that
undersized chunks vs prod's auto behavior.
Tests: 12/12 pass in `renderChunk.test.ts` (unchanged — the test suite
mocks the inner runCaptureStage call so workerCount selection is opaque
to it).
* refactor(distributed): /simplify pass on PR #906
Review pass on the parallel-capture frame-range change. Four targeted
cleanups identified by code-quality and efficiency review agents:
1. Add the missing `frameRange.endFrame - frameRange.startFrame === totalFrames`
assert. The parallel branch forwards `totalFrames` separately from
`frameRangeStart`; a caller passing mismatched values would have got a
silently wrong distribution. The sequential branch already implicitly
relied on this via its `rangeFrames = rangeEnd - rangeStart` arithmetic.
2. Collapse three near-duplicate docstrings (on `WorkerTask.outputFrameOffset`,
`executeDiskCaptureWithAdaptiveRetry.frameRangeStart`, and `runCaptureStage`'s
`frameRange`) so only the WorkerTask field carries the full contract. The
other two cross-reference it.
3. Drop the WHAT-narrating comments inside `executeWorkerTask`'s per-frame
loop. The variable names (`fileFrameIdx = i - outputOffset`) already say
what the line does; the only remaining comment flags the non-obvious
contract that the streaming callback gets the absolute index.
4. Trim the 30-line `chunkWorkerCount` block in `renderChunk` to one paragraph
explaining the one non-obvious thing (why we use `calculateOptimalWorkers`
directly instead of `resolveRenderWorkerCount`). The probeSession-wasted-on-
parallel acknowledgement stays as a 3-line follow-up flag — investigated
skipping it in this pass, but the SwiftShader probe is safety-critical and
has no per-worker equivalent, so deferred to a separate change with proper
per-worker assertion plumbing.
Tests + format + lint clean:
* `bun test parallelCoordinator.test.ts` — 7/7
* `bun test distributed/{renderChunk,plan}.test.ts` — 24/24
* `bunx oxfmt` + `bunx oxlint` — clean
## Summary
- Convert `streamingEncoder.ts`'s safety timer from a total-render hard cap to a per-frame inactivity timeout
- Reset the timer only on `accepted === true` writes — buffered writes don't count as consumer progress
- Update the `ffmpegStreamingTimeout` config doc to reflect the new semantics
## The bug
The timer was set once at spawn and fired SIGTERM unconditionally at `ffmpegStreamingTimeout` ms — turning a "FFmpeg is hung" guard into a hard cap on total render duration. Slow-but-progressing captures (CI runner under load, large compositions, slower compositor paths after [#838](https://github.com/heygen-com/hyperframes/pull/838)'s always-clip change) regularly exceeded the 600s default and were killed mid-encode. The symptom surfaced as:
```
Streaming encode failed: FFmpeg exited with code 255
video:NNNkB audio:0kB ...
[libx264 @ ...] frame I:3 Avg QP:12.91 size: 73263
[libx264 @ ...] frame P:431 Avg QP:14.72 size: 31633
...
[libx264 @ ...] kb/s:7661.05
Exiting normally, received signal 15.
```
libx264 had encoded most frames cleanly; SIGTERM arrived during the encode, libx264 printed its end-of-encode stats, and Node observed a non-zero exit. The `audio:0kB` in stderr is incidental — `streamingEncoder` is video-only; audio is muxed later in `assembleStage`.
Downstream reproduction: `style-13-prod` fails deterministically in `heygen-com/hyperframes-internal` CI after bumping `@hyperframes/producer` from 0.6.7 → 0.6.10. Bisects to #838 widening the SDR capture path at dpr=1 — same composition shape, slower per-frame, total render now crosses 600s.
## The fix
Convert the timer to a heartbeat: each `writeFrame` that goes through to the kernel pipe (i.e. `stdin.write` returns `true`) resets it. Only true hangs (no successful frame write for the timeout window) trip SIGTERM now; "slow but progressing" renders are unbounded.
Crucially, the heartbeat does **not** reset on `accepted === false`. A `false` return means Node had to buffer the write because FFmpeg hasn't drained the pipe yet — that's not proof of consumer progress, just proof we produced. Without this distinction, a hung FFmpeg with a live Chrome would queue frames into Node's writable buffer indefinitely (no backpressure path back to the capture loop) and grow until OOM. In steady state with a slow-but-alive FFmpeg, writes alternate between `true` and `false` as the buffer drains and refills; the `true`s are enough to keep the heartbeat ticking.
Renames are intentionally avoided — `ffmpegStreamingTimeout` keeps its name and `600_000` default; only the semantics changed. The config doc spells out the new behavior so downstream consumers know what 600s now means.
## Test plan
- [x] **Slow-but-progressing capture** (`accepted=true`): 9× `writeFrame` at 900ms intervals (under the 1000ms threshold) — encoder stays alive through 8.1s. Stall past the threshold — SIGTERM fires.
- [x] **Stalled FFmpeg with live producer** (`accepted=false`): override `stdin.write` to return false; pump 9× `writeFrame` at 900ms intervals. SIGTERM still fires inside the 1000ms window — buffered writes don't keep the heartbeat alive.
- [x] Existing 33 tests in `streamingEncoder.test.ts` still pass
- [x] Lint (`oxlint`) + format (`oxfmt --check`) clean
- [ ] CI regression suite
🤖 Generated with [Claude Code](https://claude.com/claude-code)
## Summary
- **Enable browser pool by default** (`enableBrowserPool: true`) — parallel capture workers now share a single Chrome process via reference-counted pool instead of each spawning their own (~256MB each). A 6-worker render drops from 7+ browser parent processes to 1 shared pool.
- **Add launch-promise deduplication** in `acquireBrowser` — when multiple workers race into the pool simultaneously (via `Promise.all`), they await the same launch Promise instead of each triggering a separate Chrome spawn. Same pattern as the existing `_autoBrowserGpuModeCache` for GPU probes.
- **Add `connected` health check** on pool hit — if Chrome crashes mid-render, subsequent acquires detect the dead browser and launch fresh instead of returning a stale reference.
- **Add `drainBrowserPool()`** for explicit cleanup between independent render jobs.
- **CLI studio server** now uses the shared pool instead of its own redundant `enableBrowserPool: false` singleton, so thumbnail generation shares Chrome with render workers.
## Problem
The engine had a reference-counted browser pool (`browserManager.ts:73-75`) but it was **disabled by default** (`enableBrowserPool: false`). This meant:
1. **Every parallel worker spawned its own Chrome** — a `--workers 6` render launched 7+ independent Chrome processes (1 probe + 6 workers), each ~256MB.
2. **The pool had a race condition** — even if manually enabled, concurrent workers calling `acquireBrowser()` via `Promise.all` could all see `pooledBrowser === null` before the first launch completed, spawning N Chromes instead of 1.
3. **No crash recovery** — if Chrome died, the pool still held the dead reference. Subsequent acquires got a disconnected browser.
4. **CLI studio server ran its own singleton** — `studioServer.ts` explicitly set `enableBrowserPool: false` and managed a separate browser, so thumbnails and renders could never share.
Over time, orphaned Chrome processes accumulated across renders and previews. We observed **344 headless Chrome processes** consuming **569% CPU and 20% memory** on a dev machine.
## Before / After (6-worker parallel render)
| Metric | Before (pool off) | After (pool on) |
|--------|-------------------|-----------------|
| Browser parent processes | 7+ (1 probe + 6 workers) | **2** (1 GPU probe + 1 shared) |
| Total Chrome processes (with helpers) | 40-50+ | **14** |
| Memory during capture | ~20%+ | **4.6%** |
| Render time (1200 frames, 30fps) | ~64s | **53s** (~17% faster) |
| Post-render orphans | Accumulated over time | **0** |
## Changes
| File | Change |
|------|--------|
| `engine/src/config.ts` | `enableBrowserPool` default `false` → `true` |
| `engine/src/services/browserManager.ts` | Extract `launchBrowser()`, add `_pooledBrowserLaunchPromise` dedup, add `connected` check on pool hit, add `drainBrowserPool()` and `_resetBrowserPoolForTests()` |
| `engine/src/index.ts` | Export `drainBrowserPool` |
| `engine/src/services/browserManager.test.ts` | Pool dedup and drain tests |
| `cli/src/server/studioServer.ts` | Remove `enableBrowserPool: false` override — thumbnails now share the pool |
| `producer/src/services/browserManager.ts` | Re-export `drainBrowserPool` |
## Backward compatibility
- `PRODUCER_ENABLE_BROWSER_POOL=false` env var disables pooling (same as before).
- Callers passing `{ enableBrowserPool: false }` explicitly still get isolated browsers.
- Tests that set `enableBrowserPool: false` in their config fixtures continue to work.
## Test plan
- [x] Engine tests pass (597/597)
- [x] Producer tests pass (406/407, 1 pre-existing flaky test in `pngDecodeBlitWorkerPool`)
- [x] Build passes (lint, format, typecheck all green via lefthook pre-commit)
- [x] Manual render: `shortform-financial` with `--workers 6` → 1200 frames in 53s, 0 orphaned Chrome processes after completion
- [x] Process monitoring during render confirmed 2 browser parents (1 GPU probe + 1 shared pool) instead of 7+
* fix(cli): prefer puppeteer cache + numeric version sort (staff review)
Two correctness fixes from PR #821 self-review:
1. Cache priority order. Previous order was hyperframes-managed cache →
puppeteer cache. HF cache is pinned to CHROME_VERSION (131-era) which
lags 17+ releases behind upstream; if a user separately installed a
newer chrome-headless-shell via @puppeteer/browsers install, the CLI
would silently hand engine the older HF-cache binary while engine's
own resolveHeadlessShellPath would have picked the newer one. Flip
the priority so puppeteer cache wins, matching engine semantics.
2. Numeric (not lexicographic) version sort. `readdirSync.sort().reverse()`
over names like `linux-148.0.7778.97` and `linux-99.0.6533.123` would
return `linux-99...` first because character '9' outranks '1'. Parse
each name into integer segments and compare them numerically.
Tests: add both-caches-populated and linux-148-beats-linux-99 cases.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
* perf(engine): page-side compositing for shader transitions (opt-in spike)
Add an opt-in `--page-side-compositing` flag (CLI) backed by a new engine
config field `enablePageSideCompositing` and env var `HF_PAGE_SIDE_COMPOSITING`.
When set, SDR shader-transition compositions skip the Node-side layered blend
(the hf#677 chain) and instead run the shader inside Chrome via a page-side
WebGL canvas; the engine then captures ONE opaque RGB frame per output frame
via the existing streaming capture path.
This is the strongest non-beginFrame perf lever for Mac users, who cannot
take the beginFrame `~5×` path (Chromium structural limit, crbug.com/40656275).
Stacks on top of the hf#677 1.95× baseline.
Default OFF — existing fixture pins (byte-exact MP4 output) are preserved.
Opt-in path is intentionally PSNR-pinned, not byte-equal (WebGL is f32; Node
is f64). HDR content forces the existing layered path regardless.
Implementation:
- engine: new `EngineConfig.enablePageSideCompositing` (default false).
- producer/fileServer: new `HF_PAGE_SIDE_COMPOSITING_STUB` early-page script
injected into the served HTML head when the flag is on.
- producer/renderOrchestrator: when the flag + no HDR + no png-sequence,
route SDR transitions through the streaming path instead of the layered
HDR stage.
- shader-transitions: new `engineModePageComposite.ts` installs a fullscreen
WebGL compositor overlay and wraps `window.__hf.seek` so each seek inside
a transition window captures both scenes via the Chromium
`drawElementImage` API to GL textures, runs the fragment shader, and
displays the composited result on the overlay canvas. The engine takes
one screenshot per frame and sees the composited overlay.
- cli: new `--page-side-compositing` flag sets `HF_PAGE_SIDE_COMPOSITING=true`
before producer load.
- scripts/page-side-compositing-smoke: bundled-CLI smoke that renders a
representative fixture with and without the flag, validates the canary
strings are in the shipped bundles, and writes a wall-time pair.
Determinism trade documented in the engine config doc-comment. The smoke
script enforces the bundled-CLI validation discipline from prior perf work
(see internal feedback note `validate_bundled_cli_not_dev_path`).
Runtime requirement: Chromium's `CanvasDrawElement` feature (already
enabled by the engine's `--enable-features=CanvasDrawElement` launch flag).
When the runtime feature is unavailable, the page-side installer logs a
warning and falls back to opacity-flip mode — the engine still takes the
streaming path; the transition window degrades to a hard scene swap. Vance
will validate on Mac Chrome where the feature is supported.
Co-Authored-By: Vai <vai@heygen.com>
* fix(shader-transitions): use html2canvas for page-side compositor capture
The original drawElementImage approach fails in engine render mode because
the virtual-time shim prevents Chromium from generating paint records for
cloned elements. drawElementImage requires a cached paint record from the
browser's compositor — clones created at capture time never receive one
because (a) shimmed rAFs deadlock inside the seek wrapper, (b) original
rAFs don't produce real paints under virtual-time control, and
(c) layoutsubtree canvases don't apply CSS stylesheet rules to children.
Switch scene capture to html2canvas (foreignObjectRendering: false), the
same JS-based renderer already used by the preview-mode fallback path in
capture.ts. html2canvas reads computed styles and renders via its own
canvas drawing pipeline with no dependency on the browser paint cycle.
Also fixes:
- Engine seek must return the result so Puppeteer awaits async seek
promises (frameCapture.ts).
- GSAP opacity cache: compositor must restore scene opacity before seek,
not after — GSAP caches inline values and skips re-writes.
- Support check gates on WebGL availability, not drawElementImage.
Perf: 15-scene shader-perf fixture (28s, 14 transitions, 30fps)
Baseline (Node-side layered): 137s
Page-side (html2canvas+WebGL): 33s → 4.1× speedup
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* refactor(shader-transitions): simplify review fixes for page-side compositor
- Use uploadTexture (zeroes canvas backing store after upload) to prevent
~2.2GB transient memory pressure across 280 html2canvas calls per render
- Add ignoreElements + stabilizeTransformedBoxShadows to html2canvas call,
matching the preview-path capture.ts behavior
- Parallelize from/to scene captures with Promise.all
- Wrap post-capture render in try/finally so opacity is always restored
- Fix WebGL context leak in isPageSideCompositingSupported probe
- Remove dead ResolvedTransition.index field
- Export stabilizeTransformedBoxShadows from capture.ts
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* fix(producer): unify page-side compositing gating and Docker forwarding
Addresses three issues from staff review:
1. ignoreElements filter stripped all in-scene canvases (Chart.js, D3,
p5.js) — narrowed to data-no-capture only since the compositor canvas
is a body sibling never in the scene subtree.
2. Docker mode silently dropped --page-side-compositing — thread
pageSideCompositing through DockerRenderOptions/buildDockerRunArgs
with regression tests.
3. Fragmented gating across 4 independent sites could disagree:
- Stub injection gated only on cfg flag (leaked into HDR/alpha)
- Probe-created fileServer never got the stub
- needsAlpha (WebM/MOV) not excluded from the gate
- WebGL-unavailable fallback claimed layered path would run but
orchestrator had already disabled it
Fix: compute stub injection at the same site as the layered-bypass
decision (after hasHdrContent is known), using addPreHeadScript on
the already-running fileServer. Single predicate now gates both
decisions, including !needsAlpha.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* perf(engine): two-phase drawElementImage capture for page-side compositing
Replace html2canvas with native drawElementImage for scene capture in
the page-side compositor. drawElementImage reads from the browser's own
paint cache, giving pixel-identical output to the preview path.
The blocker was that cloned elements inside layoutsubtree canvases have
no cached paint record under virtual time — the compositor only paints
when explicitly triggered. Fix: split the seek+composite into two phases
with an engine-forced paint between them.
Phase 1 (seek wrapper, page-side):
- GSAP seek positions the timeline
- Clone FROM/TO scenes into visible layoutsubtree staging canvases
- Set window.__hf_page_composite_pending flag
Engine paint force (frameCapture.ts):
- Detect pending flag after seek returns
- Fire micro Page.captureScreenshot (1x1 clip) via CDP to force the
browser compositor to paint all visible elements including staging
canvas children
Phase 2 (page.evaluate, page-side):
- drawElementImage reads the now-valid paint records
- Upload textures to WebGL, run shader, show GL overlay
Key insight: staging canvases must be visible (not opacity:0) for the
browser to paint their children. They sit at z-index:-9998, behind
the main DOM and covered by the GL overlay during transitions.
Perf: 15-scene fixture (28s, 14 transitions, 30fps):
Baseline (Node-side layered): 137s
html2canvas + WebGL: 33s (3.7×)
drawElementImage + WebGL: 21s (6.6×)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* perf(engine): optimize two-phase compositor hot path
- uploadTextureSource instead of uploadTexture: eliminates ~2.3GB of
canvas buffer alloc/dealloc churn (persistent staging canvases don't
need the one-shot zeroing behavior)
- Fold hasPending check into seek page.evaluate: eliminates one CDP
round-trip per frame (~700 unnecessary IPC calls on non-transition
frames)
- Fix renderShader error handling: on failure, leave source scenes
visible as fallback instead of hiding both scenes + GL overlay
(which produced black frames)
- Move mutable state declarations above resolveComposite to prevent
TDZ risk on refactor
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* fix(engine): staff review — staging cleanup, pending flag, beginFrame guard
- Clear staging canvas children when leaving transition window (prevents
visible clone bleed-through on transparent compositions)
- Clear __hf_page_composite_pending on all resolveComposite exit paths
- Guard micro-screenshot paint force against beginFrame mode (CDP
Page.captureScreenshot conflicts with beginFrame compositor control)
- Update CLI flag description: document video/canvas limitation, remove
stale PSNR claim
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* feat(engine): default-on page-side compositing for SDR shader transitions
Page-side compositing is now enabled by default for SDR shader-transition
renders without video content. The 6.6× speedup applies automatically —
no flag needed.
Auto-disables when:
- HDR content detected
- Alpha output (WebM/MOV/PNG-sequence)
- Composition contains <video> elements (cloneNode loses playback state)
- beginFrame capture mode (Linux headless)
Use --no-page-side-compositing to force the Node-side layered path.
Changes:
- Engine config: enablePageSideCompositing defaults to true
- CLI: flag default flipped to true; --no-page-side-compositing disables
- Orchestrator: added composition.videos.length === 0 gate
- Docker: forwards --no-page-side-compositing when explicitly disabled
- Config tests updated for new default
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* feat(engine): support video elements on page-side compositing fast path
Three-phase capture protocol lets shader transitions render video scenes
without falling back to the slow Node-side layered pipeline:
1. Seek → compositor records transition metadata, sets pending flag
2. onBeforeCapture → video frame injector updates <img> replacements
3. prepare → cloneNode picks up current video frames, img.decode() awaits
4. micro-screenshot → forces browser to paint cloned elements
5. resolve → drawElementImage reads paint records, shader composites
Key changes:
- Remove `composition.videos.length === 0` gate from orchestrator
- Split compositor resolve into prepare (clone) + resolve (shader)
- Move onBeforeCapture before compositor prepare in frameCapture.ts
- Await img.decode() on cloned data-URI images to prevent stale frames
- Stop manipulating scene opacity in compositor (GL canvas overlay suffices)
- Add gsap.set declaration for shader-transitions ambient types
- Add video_missing_timing_attrs lint rule for <video> without id/data-start/data-end
Performance: compositions with video now render at 7.5s (6 workers) instead
of 2m38s on the layered path.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* fix(core): auto-inject data-start on video/audio so frame extraction works without explicit attrs
The timing compiler now injects data-start="0" on <video> and <audio>
elements that lack it. This makes discoverMediaFromBrowser() find the
element (it queries video[data-start]), so the frame extraction pipeline
activates automatically. Videos "just work" without requiring authors to
add data-start, data-end, or id attributes.
Also removes the video_missing_timing_attrs lint rule — the compiler
handles the missing attributes automatically, so the lint rule would
only false-positive.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* feat(core): add data-hf-auto-start sentinel on auto-injected video timing
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* feat(producer): add discoverVideoVisibilityFromTimeline for runtime video discovery
Seeks the GSAP timeline in Puppeteer to discover when each video's parent
scene is visible (opacity > 0). Uses coarse sampling at 100ms steps followed
by binary search refinement to frame-level precision (1/60s). Only processes
videos with the data-hf-auto-start sentinel so author-specified timing is
never overridden.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* feat(producer): integrate runtime video visibility discovery into probe stage
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* fix(producer): trigger browser probe for auto-start videos, remove debug logging
The probe stage was skipping browser launch when composition duration was
already known, which meant discoverVideoVisibilityFromTimeline never ran.
Now needsBrowser also checks for data-hf-auto-start sentinel in compiled HTML.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* fix(scripts): use mkdtempSync for smoke test work directory
Replaces hardcoded /tmp/hf-page-side-smoke with a unique temp directory
via mkdtempSync to resolve CodeQL "insecure temporary file" alert.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* style: format smoke test script
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: Vai <vai@heygen.com>
* fix(engine): preserve video frame replacement geometry
* test(producer): cover video overlay stretch regression
* fix(engine): always pass clip to Page.captureScreenshot
Without an explicit clip, Chrome can resolve replaced-element sizing
differently at dpr=1 when full-bleed absolute videos interact with
overlay layers — producing anisotropic frame stretching on some
compositor paths. Always passing clip with scale=dpr (including 1)
ensures geometry is locked to the measured viewport dimensions.
Credit: brian-t-allen (#837)
* test(producer): regenerate style-9-prod baseline for always-clip capture path
The always-clip change in screenshotService.ts routes Chrome through a
different compositor capture path at dpr=1, producing different video
frame compression artifacts. Regenerated inside Dockerfile.test to match
CI environment.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
* feat(studio): add pasteboard background to preview viewport
Adds bg-neutral-800 to the preview viewport so the area outside the
canvas is visually distinct from the composition content — consistent
with professional video editors (Premiere, DaVinci, Figma).
* feat(studio): pasteboard background and canvas outline around preview
- NLEPreview: viewport gets bg-neutral-700 (#404040) as the pasteboard
color surrounding the canvas — distinct from the app chrome (#0a0a0a)
- Player wrapper: drop bg-black so the pasteboard shows around the canvas
(loading overlays still cover the area with bg-black during load)
- Player: set host background to transparent via inline style (overrides
:host { background: #000 } in shadow DOM), and inject a style rule into
the open shadow root so .hfp-container has overflow:visible and the
canvas iframe gets a thin white ring + soft drop-shadow — making the
canvas boundary legible against the pasteboard
* feat(studio): disable manual positioning JSON by default, add toggle
Manual edits were always stored in `.hyperframes/studio-manual-edits.json`,
making it hard to share source without the sidecar file and easy to
accidentally reposition elements via drag.
Changes:
- `enabled` field added to `StudioManualEditManifest` (defaults to `false`
when absent — existing projects are unaffected until they opt in)
- Drag handles, resize, and rotation handles are hidden when disabled
- Layout X/Y/W/H/R fields in the Design panel are read-only when disabled
- "Manual positioning" toggle added at the bottom of the Design panel,
visible whether or not an element is selected
- Toggle state is persisted to `.hyperframes/studio-manual-edits.json`
so each project can opt in independently
- `STUDIO_PREVIEW_MANUAL_EDITING_ENABLED` env flag still acts as a hard
cap (env off → feature off regardless of project setting)
* feat(studio): enable manual positioning by default (opt-out)
* feat(studio): allow absolute elements to drag without toggle; gate JSON-backed drag behind toggle
* feat(studio): persist positions directly to HTML; remove JSON sidecar and manual positioning toggle
Replace the `.hyperframes/studio-manual-edits.json` sidecar with inline-style
persistence baked directly into the HTML source. Drag/resize/rotation values
are written as CSS custom properties (`--hf-studio-offset-x/y`, `--hf-studio-width/height`,
`--hf-studio-rotation`) plus `translate`/`width`/`height`/`rotate` inline styles via
`persistDomEditOperations` — no re-apply step needed on load.
Key changes:
- `sourcePatcher`: add `value: string | null` to `PatchOperation` — null removes the
property/attribute from the HTML tag instead of setting it
- `manualEditsDom`: add `build*Patches` / `buildClear*Patches` helpers that capture live
element state into `PatchOperation[]` for HTML source writes; add
`reapplyPositionEditsAfterSeek` (DOM-query-based seek hook, queries data-attribute markers)
- `manualEdits.ts`: remove `applyStudioManualEditManifest` and all manifest target
resolution; export `reapplyPositionEditsAfterSeek`; keep seek/play wrap infrastructure
- `useManifestPersistence`: remove all JSON I/O — no disk read on load, no manifest
state, no toggle state; `applyCurrentStudioManualEditsToPreview` now only installs
seek hooks via `reapplyPositionEditsAfterSeek`
- `useDomEditCommits`: replace `commitStudioManualEditManifestOptimistically` calls with
direct DOM apply + `commitPositionPatchToHtml` (queued HTML patch write, skipRefresh)
- `DomEditOverlay`: remove `manualEditsEnabled` prop; revert all `canMove || manualEditsEnabled`
gates to just `canApplyManualOffset` — every draggable element is always draggable
- `PropertyPanel`: remove `ManualPositioningToggle` component and all toggle props
- `manualEditsParsing/manualEditsTypes`: remove manifest types, upsert functions, and
`STUDIO_MANUAL_EDITS_PATH`; keep `finiteNumber`, `readStudioFileChangePath`,
`roundRotationAngle`, and snapshot/CSS-property types
* fix(studio): sync keyboard shortcut handler with main; fix keepPlaying seek assertions in test
* fix(studio): strip GSAP-cached translate from transform on path offset apply
* fix(studio): remove Reset edits button from design panel
* feat(studio): wire reloadPreview into manifest persistence; drop stale group-selection refresh
- Pass `reloadPreview` into `useManifestPersistence` so undo/redo reloads
via the refresh-key path instead of directly touching the iframe.
- Remove `refreshDomEditGroupSelectionsFromPreview` from commit handlers;
HTML is now the source of truth so no stale-ref refresh is needed.
- Add `manualEditsRenderScript` helper; export via studio-api and apply
it in `htmlCompiler` during HTML compilation.
* fix(studio): prevent root composition from being selected; correct overlay drift on resize
- Guard `getDomLayerPatchTarget` against elements with `data-composition-id`
so the root composition div is never returned as a visual selection target.
- Apply the same guard to the raw `elementFromPoint` fallback in
`getPreviewTargetFromPointer`, which was the actual escape path.
- Thread `iframeRef` into gesture handler opts; after applying draft
dimensions during resize, re-read the element BCR via `toOverlayRect`
and update the overlay box position to compensate for visual drift on
elements with centered transform-origin (e.g. GSAP scale tweens).
* fix(studio): correct resize overlay for scaled elements; block invisible element selection
- Resize: use BCR from `toOverlayRect` for both position and size after
applying draft dimensions — GSAP scale makes visual size diverge from
raw CSS size, BCR is the only accurate source during a gesture.
- Click selection: add `isElementComputedVisible` guard to the
`elementFromPoint` fallback so opacity-0 / autoAlpha-hidden elements
cannot be selected even though the browser hit-test returns them.
* fix(studio): reload preview on external file changes via SSE/HMR
Share the app-level domEditSaveTimestampRef with useManifestPersistence
so the SSE/HMR handler can suppress echoes from all studio saves (code
tab, timeline, DOM edits), then call reloadPreview() for non-motion
external changes that aren't echoes of our own saves.
* fix(studio): suppress post-resize click to keep selection on resized element
* fix(studio): serve registry blocks without index.html in preview
Blocks ship as {id}.html + assets/ with no index.html. The preview
route hard-coded index.html so these projects returned 404 and their
assets (e.g. korea-map.png, map-nyc-paris.png) were never served.
Add resolveProjectMainHtml() that falls back to {id}.html, thread the
resolved compositionPath through transformPreviewHtml and
injectStudioPreviewAugmentations, and update listProjects() in the
vite adapter to surface block directories in the project list.
* fix(render): preserve studio drag/resize/rotation offsets in rendered video
Three issues caused studio-edited positions to be lost during rendering:
1. The seek-reapply script used setInterval to wrap window.__hf.seek, but
Puppeteer's page.evaluate() calls don't yield the event loop for
macrotasks — the interval never fired, so reapplyAll() never ran after
GSAP seeks. Fix: use Object.defineProperty to trap writes to the seek
property, wrapping it synchronously the instant the bridge assigns it.
2. MEDIA_VISUAL_STYLE_PROPERTIES (copied from <video> to proxy <img>
during render) included "transform" but not "translate", "rotate", or
"scale" — the CSS Transforms Level 2 individual properties used by
studio drag/resize/rotation. The proxy was positioned at offsetLeft/
offsetTop without the translate offset.
3. getViewportMatrix (HDR compositor) only read cs.transform, missing
individual transform properties entirely. Added composeIndividualTransforms
to build the translate × rotate × scale matrix and compose it before
the legacy transform matrix.
* fix(studio): select elements with pointer-events: none in preview
Compositions often set pointer-events: none on scenes, avatar wrappers,
and decorative layers. elementsFromPoint() skips these elements entirely,
making them unselectable in the Studio. Fix: temporarily inject a
* { pointer-events: auto !important } stylesheet during hit-testing, then
remove it immediately after.
Also adds a pointer_events_none lint rule (info severity, visible with
--verbose) so authors know which selectors may affect Studio selection.
## Summary
PR 3 of 5 in the hf#732 decomposition stack. Adds a `worker_threads`-based pool that runs the shader-transition blend (one of 15 transition shaders) on a fixed-size worker pool. **No production wiring yet** — the pool stands alone; PR 4 wires it.
The shader blend is a hot inner loop over every pixel of every transition frame at 16bpc. Moving it off the main event loop removes the JS-event-loop ceiling that capped throughput in earlier hf#732 iterations.
### New files
- `packages/producer/src/services/shaderTransitionWorker.ts` — worker entry. Imports from `@hyperframes/engine/shader-transitions` (zero-import TS source).
- `packages/producer/src/services/shaderTransitionWorkerPool.ts` — fixed-size pool. Uses `transferList` so the 16bpc HDR `from`/`to`/`out` buffers move by ownership.
- `packages/producer/src/services/shaderTransitionWorkerPool.test.ts` — 6 vitest tests pinning byte-equivalence across all 15 shaders, transferList correctness, pool lifecycle. All pass.
### Build wiring
- `packages/cli/tsup.config.ts`: third tsup entry emits `dist/shaderTransitionWorker.js`.
- `packages/producer/build.mjs`: fourth esbuild entry for direct producer consumers.
- `packages/engine/package.json`: adds `./shader-transitions` subpath export.
## Stack
Stacked on top of #757 (PR 2: pngDecodeBlit pool). No behavior change in any render.
## Test plan
- [x] 6 pool tests pass
- [x] Producer + engine typecheck clean
- [x] oxlint clean
— Vai
## Summary
PR 2 of 5 in the hf#732 decomposition stack. Adds a `worker_threads`-based pool that offloads PNG decode + alpha-blit onto a fixed-size pool. **No production wiring yet** — the pool stands alone and ships behind a later PR in the stack.
### New files
- `packages/producer/src/services/pngDecodeBlitWorker.ts` — worker entry. Imports from `@hyperframes/engine/alpha-blit` (zero-import TS source, survives the `new Worker(<path>)` loader boundary).
- `packages/producer/src/services/pngDecodeBlitWorkerPool.ts` — fixed-size pool with `run()` API. Uses `transferList` for buffer ownership transfer (no 16bpc HDR buffer copies).
- `packages/producer/src/services/pngDecodeBlitWorkerPool.test.ts` — 6 vitest tests pinning byte-equivalence with inline path, transferList correctness, concurrent dispatch, termination semantics. All pass.
### Build wiring
- `packages/cli/tsup.config.ts`: second tsup entry emits `dist/pngDecodeBlitWorker.js` next to `dist/cli.js`. Without this entry the pool's `new Worker(<path>)` would fail at runtime in the shipped CLI.
- `packages/producer/build.mjs`: third esbuild entry mirrors the wiring for direct producer consumers.
- `packages/engine/package.json`: adds `./alpha-blit` subpath export pointing at `src/utils/alphaBlit.ts`.
## Stack
Stacked on top of #756 (PR 1: worker-count cap). No behavior change in any render.
## Test plan
- [x] 6 pool tests pass
- [x] Producer + engine typecheck clean
- [x] oxlint clean
— Vai
## Summary
PR 1 of 5 in the hf#732 decomposition stack. Bumps `parallelCoordinator`'s worker-count caps so high-core hosts can actually surface their hardware to renders:
- `ABSOLUTE_MAX_WORKERS`: 10 → 24 (explicit `--workers 16` now surfaces 16 DOM sessions instead of being silently clamped).
- `DEFAULT_SAFE_MAX_WORKERS` constant → `defaultSafeMaxWorkers()` function returning `max(6, min(16, floor(cpus/8)))`. On <=32-core hosts: unchanged (still 6). On 64/96/128-core hosts: 8/12/16.
No behavior change for typical hosts. Required prerequisite for the hybrid shader-transition path landed in PR 4.
## Test plan
- [x] Existing 7 `parallelCoordinator` tests pass
- [x] Engine typecheck clean
- [x] oxlint clean
## Stack
This is the base of the hf#732 decomposition stack:
1. **PR 1 (this)** — perf(engine): worker-count cap bump
2. PR 2 — feat(producer): add pngDecodeBlitWorkerPool
3. PR 3 — feat(producer): add shaderTransitionWorkerPool
4. PR 4 — perf(producer): hybrid layered/parallel path (the 2.22× speedup)
5. PR 5 — perf(producer): pipeline capture and shader-blend per-frame
Replaces the closed hf#732. See that issue for the original investigation; the architectural mismatch with #733's `captureHdrStage` extraction made a clean rebase impossible.
— Vai
Part of Phase 2 of the distributed rendering plan (determinism hardening).
See DISTRIBUTED-RENDERING-PLAN.md §17.2 (PR 2.7 row).
Distributed renders mix audio once at `plan()` time against the
composition's declared duration; the actual assembled video duration is
`Σ(chunkFrames) / fps`. Even with closed-GOP concat-copy the absolute
result is deterministic, but downstream muxers (especially ffmpeg's
`-shortest` plus Apple's mov demuxer) are sensitive to ±1ms audio/video
drift and produce silent "audio cuts off early" or "video freezes on the
last frame" bugs.
Adds packages/producer/src/services/render/audioPadTrim.ts:
- buildPadTrimAudioArgs(audio, out, sourceSec, targetSec) — pure helper
that decides the operation (pad/trim/copy) and emits the matching
ffmpeg argv. Uses `apad=pad_dur=Δ` (re-encode to AAC because filters
can't combine with `-c:a copy`), `-t target -c:a copy` (trim is a
lossless AAC packet boundary snap), or a plain `-c:a copy` when the
delta is below ~1ms.
- padOrTrimAudioToVideoFrameCount(input) — probes the assembled video
for exact frame count (`-count_packets` + `nb_read_packets`, which
equals frame count when chunks were encoded with `-bf 0` as Phase 2's
PR 2.1 already enforces), probes the audio for current duration,
computes target = `frameCount * fpsDen / fpsNum`, runs ffmpeg with the
args from the pure helper. Probes and ffmpeg runner are injectable so
unit tests don't shell out.
Six-decimal-place seconds formatting avoids ffmpeg's inconsistent handling
of scientific notation in time args across versions.
No caller invokes either function yet — Phase 3's `assemble()` will run
this after the chunk concat-copy step, before muxing audio onto the final
mp4/mov output.
15 unit tests at packages/producer/src/services/render/
audioPadTrim.test.ts pin both layers: the pure arg builder for all three
operations (incl. NTSC fps), and the wrapper for normal flow, probe
failures, invalid video info, and ffmpeg failures.
In-process behavior is unchanged. The producer's existing
`muxVideoWithAudio` path in chunkEncoder is untouched.
This is part of a stack of 10 PRs; this is PR 7 of 10.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Part of Phase 2 of the distributed rendering plan (determinism hardening).
See DISTRIBUTED-RENDERING-PLAN.md §5.2 (lastFrameCache row) and §17.2
(gating table).
Adds `discardWarmupCapture(session, frameIndex=0, time=0, innerCapture?)`
in packages/engine/src/services/frameCapture.ts. Performs one capture
through the standard `captureFrameCore` path, throws the buffer away, and
restores the session's perf and BeginFrame damage counters.
Distributed chunk workers need this because Chrome's BeginFrame screenshot
pipeline maintains a per-process `lastFrameCache`: when a captured frame's
`hasDamage` reports `false`, the screenshot path returns the previously
captured buffer. For chunk N (N > 0) the worker has no prior frame in its
cache, so the very first capture's `hasDamage` reporting diverges from
what an in-process render at the same absolute frame index would see (the
in-process renderer always has frame N-1 cached). Running a discarded
warmup capture before the first real capture primes the cache so chunk
output is byte-identical to in-process output.
The wrapper:
- Takes an injectable `innerCapture` so tests can stub the Chrome path
(default is the real `captureFrameCore`).
- Restores `session.capturePerf`, `beginFrameHasDamageCount`, and
`beginFrameNoDamageCount` after the inner call — even on error — so
warmup captures don't pollute `getCapturePerfSummary()` averages.
- Writes no file to disk.
In-process behavior is unchanged: no caller invokes the new helper yet.
Phase 3's `renderChunk()` will run it as the first step after
`initializeSession` resolves.
Re-exported from packages/engine/src/index.ts.
7 unit tests at packages/engine/src/services/
frameCapture-discardWarmup.test.ts cover the post-conditional contract:
single inner-capture invocation, perf/damage restoration on success,
restoration on error, no-fs-write.
This is part of a stack of 10 PRs; this is PR 6 of 10.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
James Russo