Files
hyperframes/packages/engine/src/index.ts
T
JamesandClaude Opus 4.7 62317f7f3a feat(producer): audio post-pad/trim helper for assemble
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>
2026-05-13 04:36:11 +00:00

242 lines
8.2 KiB
TypeScript

/**
* @hyperframes/engine
*
* Seekable web page to video rendering engine.
* Framework-agnostic: works with GSAP, Lottie, Three.js, CSS animations,
* or any web content that implements the window.__hf seek protocol.
*
* ## Error Convention
*
* Engine services use three error strategies depending on the operation type:
*
* - **Orchestration services throw on failure.** Browser launch, session init,
* frame capture, and CDP operations propagate errors as thrown exceptions.
* Callers are expected to catch and handle (e.g. frameCapture, browserManager,
* screenshotService, videoFrameExtractor.extractVideoFramesRange).
*
* - **FFmpeg process wrappers return `{ success, error? }` result objects.**
* Encoding, muxing, audio mixing, and streaming encode operations never reject.
* They resolve with a result that includes `success: boolean` and an optional
* `error` string (e.g. chunkEncoder, audioMixer, streamingEncoder).
*
* - **Cleanup and teardown functions never throw.** Browser close, session close,
* temp directory removal, and resource release swallow errors via `.catch(() => {})`
* to avoid masking the original failure (e.g. releaseBrowser, closeCaptureSession,
* FrameLookupTable.cleanup).
*
* - **Optional lookups return `T | undefined` or `T | null`.**
* Functions that may legitimately find nothing (resolveHeadlessShellPath,
* getFrameAtTime, detectGpuEncoder) return a nullable value instead of throwing.
*
*/
// ── Protocol types ─────────────────────────────────────────────────────────────
export type {
HfProtocol,
HfMediaElement,
HfTransitionMeta,
CaptureOptions,
CaptureVideoMetadataHint,
CaptureResult,
CaptureBufferResult,
CapturePerfSummary,
} from "./types.js";
// ── Configuration ──────────────────────────────────────────────────────────────
export { resolveConfig, DEFAULT_CONFIG, type EngineConfig } from "./config.js";
// ── Browser management ─────────────────────────────────────────────────────────
export {
acquireBrowser,
releaseBrowser,
resolveHeadlessShellPath,
resolveBrowserGpuMode,
buildChromeArgs,
ENABLE_BROWSER_POOL,
type BuildChromeArgsOptions,
type CaptureMode,
type AcquiredBrowser,
} from "./services/browserManager.js";
// ── Frame capture pipeline ──────────────────────────────────────────────────────
export {
createCaptureSession,
initializeSession,
closeCaptureSession,
captureFrame,
captureFrameToBuffer,
discardWarmupCapture,
getCompositionDuration,
getCapturePerfSummary,
prepareCaptureSessionForReuse,
type CaptureSession,
type BeforeCaptureHook,
type DiscardWarmupInnerCapture,
} from "./services/frameCapture.js";
// ── Screenshot (BeginFrame) ─────────────────────────────────────────────────────
export {
beginFrameCapture,
pageScreenshotCapture,
getCdpSession,
injectVideoFramesBatch,
syncVideoFrameVisibility,
cdpSessionCache,
initTransparentBackground,
captureAlphaPng,
applyDomLayerMask,
removeDomLayerMask,
DOM_LAYER_MASK_STYLE_ID,
type BeginFrameResult,
} from "./services/screenshotService.js";
// ── Encoding ───────────────────────────────────────────────────────────────────
export {
encodeFramesFromDir,
encodeFramesChunkedConcat,
muxVideoWithAudio,
applyFaststart,
detectGpuEncoder,
ENCODER_PRESETS,
getEncoderPreset,
type GpuEncoder,
} from "./services/chunkEncoder.js";
export type { EncoderOptions, EncodeResult, MuxResult } from "./services/chunkEncoder.types.js";
export {
spawnStreamingEncoder,
createFrameReorderBuffer,
type StreamingEncoder,
type StreamingEncoderOptions,
type StreamingEncoderResult,
type FrameReorderBuffer,
} from "./services/streamingEncoder.js";
// ── Media processing ───────────────────────────────────────────────────────────
export {
parseVideoElements,
parseImageElements,
extractVideoFramesRange,
extractAllVideoFrames,
resolveProjectRelativeSrc,
getFrameAtTime,
createFrameLookupTable,
FrameLookupTable,
type VideoElement,
type ImageElement,
type ExtractedFrames,
type ExtractionOptions,
type ExtractionResult,
type ExtractionPhaseBreakdown,
} from "./services/videoFrameExtractor.js";
export { createVideoFrameInjector } from "./services/videoFrameInjector.js";
export { parseAudioElements, processCompositionAudio } from "./services/audioMixer.js";
export type { AudioElement, AudioTrack, MixResult } from "./services/audioMixer.types.js";
// ── Parallel rendering ─────────────────────────────────────────────────────────
export {
calculateOptimalWorkers,
distributeFrames,
executeParallelCapture,
mergeWorkerFrames,
getSystemResources,
type WorkerTask,
type WorkerResult,
type ParallelProgress,
} from "./services/parallelCoordinator.js";
// ── File server ────────────────────────────────────────────────────────────────
export {
createFileServer,
type FileServerOptions,
type FileServerHandle,
} from "./services/fileServer.js";
// ── Utilities ──────────────────────────────────────────────────────────────────
export { quantizeTimeToFrame, MEDIA_VISUAL_STYLE_PROPERTIES } from "@hyperframes/core";
export {
assertSwiftShader,
readWebGlVendorInfo,
SwiftShaderAssertionError,
BROWSER_GPU_NOT_SOFTWARE,
} from "./utils/assertSwiftShader.js";
export {
extractMediaMetadata,
extractVideoMetadata,
extractAudioMetadata,
analyzeKeyframeIntervals,
type VideoMetadata,
type AudioMetadata,
type KeyframeAnalysis,
} from "./utils/ffprobe.js";
export { downloadToTemp, isHttpUrl } from "./utils/urlDownloader.js";
export {
runFfmpeg,
formatFfmpegError,
type RunFfmpegOptions,
type RunFfmpegResult,
} from "./utils/runFfmpeg.js";
export {
decodePng,
decodePngToRgb48le,
blitRgba8OverRgb48le,
blitRgb48leRegion,
blitRgb48leAffine,
parseTransformMatrix,
roundedRectAlpha,
resampleRgb48leObjectFit,
normalizeObjectFit,
type ObjectFit,
} from "./utils/alphaBlit.js";
export { groupIntoLayers, type CompositeLayer } from "./utils/layerCompositor.js";
// ── Shader transitions ────────────────────────────────────────────────────────
export {
type TransitionFn,
TRANSITIONS,
crossfade,
sampleRgb48le,
hdrToLinear,
linearToHdr,
convertTransfer,
} from "./utils/shaderTransitions.js";
export {
initHdrReadback,
uploadAndReadbackHdrFrame,
float16ToPqRgb,
buildHdrChromeArgs,
launchHdrBrowser,
} from "./services/hdrCapture.js";
export { captureScreenshotWithAlpha } from "./services/screenshotService.js";
export {
hideVideoElements,
showVideoElements,
queryVideoElementBounds,
queryElementStacking,
type VideoElementBounds,
type ElementStackingInfo,
} from "./services/videoFrameInjector.js";
export {
isHdrColorSpace,
detectTransfer,
getHdrEncoderColorParams,
analyzeCompositionHdr,
DEFAULT_HDR10_MASTERING,
type HdrTransfer,
type HdrEncoderColorParams,
type CompositionHdrInfo,
type HdrMasteringMetadata,
} from "./utils/hdr.js";
export type { VideoColorSpace } from "./utils/ffprobe.js";