mirror of
https://github.com/heygen-com/hyperframes.git
synced 2026-09-11 14:50:02 +00:00
Val
97991bbd35
Parent src-only scans skipped multi-format <video>/<audio> markup, so those elements were never extracted, downloaded, or mixed and rendered blank/silent. Lint now accepts a child <source src> as a resolvable media src.
1548 lines
60 KiB
TypeScript
1548 lines
60 KiB
TypeScript
// fallow-ignore-file complexity code-duplication
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/**
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* Audio Mixer Service
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*
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* Processes and mixes audio tracks using FFmpeg.
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*/
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import { closeSync, existsSync, mkdirSync, mkdtempSync, openSync, rmSync, writeFileSync } from "fs";
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import { join, dirname } from "path";
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import { parseHTML } from "linkedom";
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import { extractAudioMetadata } from "../utils/ffprobe.js";
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import { isNotMediaPayload } from "../utils/notMediaPayload.js";
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import { clampAudioGain } from "@hyperframes/core/audio-gain";
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import {
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downloadToTemp,
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isHttpUrl,
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UrlDownloadError,
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writeUrlDownloadTelemetry,
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} from "../utils/urlDownloader.js";
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import { DEFAULT_CONFIG, type EngineConfig } from "../config.js";
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import { formatFfmpegError, runFfmpeg, type RunFfmpegResult } from "../utils/runFfmpeg.js";
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import { unwrapTemplate } from "../utils/htmlTemplate.js";
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import { resolveMediaElementSrc, resolveProjectRelativeSrc } from "./videoFrameExtractor.js";
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import { resolveReferencedStart, type RefResolverEl } from "./referenceResolver.js";
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import { isKnownInactiveTimelineWindow } from "./mediaTimelineWindow.js";
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import type {
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AudioElement,
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AudioFailureStage,
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AudioProcessingFailure,
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AudioTrack,
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MixResult,
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} from "./audioMixer.types.js";
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import { applyVolumeEnvelopeToWav } from "./audioVolumeEnvelope.js";
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import { HF_AUDIO_FX_ATTR, parseAudioFxChain } from "@hyperframes/core/audio-fx";
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import {
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HF_AUDIO_AUTOMATION_ATTR,
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parseAutomation,
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resolveAutomation,
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sampleAutomationLane,
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VOLUME_TARGET,
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type HfAutomationLane,
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} from "@hyperframes/core/audio-automation";
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import { chainTailSeconds } from "@hyperframes/core/audio-fx-tail";
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import {
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MEDIA_RENDER_ID_ATTR,
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normalizePlaybackRate,
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parseStrictFiniteTimingNumber,
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readMediaStart,
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} from "@hyperframes/core";
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import { HF_AUDIO_GROUP_ATTR, resolveAudioGroups } from "@hyperframes/core/audio-groups";
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import { AUDIO_GROUP_RENDER_ID_ATTR } from "@hyperframes/core";
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import { applyAudioFxChain, AudioFxRenderError } from "./audioFxRender.js";
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import type { AudioVolumeKeyframe } from "./audioMixer.types.js";
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export type { AudioElement, MixResult } from "./audioMixer.types.js";
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/**
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* Filename every caller must use for the mixed-audio artifact.
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*
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* The extension is load-bearing, not cosmetic: FFmpeg picks the muxer from it,
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* and the mix is AAC-encoded. A raw ADTS `.aac` stream has nowhere to record
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* the encoder's priming delay, so those leading samples decode as real silence
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* and shift the whole track ~1024 samples (21.33 ms at 48 kHz) late against a
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* frame-accurate video track. An MP4-family container carries the delay as an
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* edit list, which every decoder then strips, so the mix lands on its authored
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* start. Keep the choice here rather than at each call site: the same file is
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* muxed into the video, shipped in a distributed plan, and handed to users as
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* the PNG-sequence sidecar, and all three have to agree.
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*/
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export const MIXED_AUDIO_FILENAME = "audio.m4a";
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/**
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* The bus key a member belongs to, as `resolveAudioGroups` keys them.
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*
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* The compiler's `data-hf-group-render-id` names one INSTANCE of a bus; the
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* author's `data-audio-group` names it only within its own composition file. A
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* sub-composition declaring a bus and its members, used twice, therefore had
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* both instances' members under one key: one sub-mix for two independent buses,
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* one instance's fader and chain over the other's audio, and — with only the
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* second muted — BOTH instances dropped from the export. Uncompiled documents
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* (the live preview) carry no stamp and read exactly as before.
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*/
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function memberGroupKey(el: RefResolverEl): string | null {
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return el.getAttribute(AUDIO_GROUP_RENDER_ID_ATTR) ?? el.getAttribute(HF_AUDIO_GROUP_ATTR);
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}
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function clampVolume(volume: number): number {
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return clampAudioGain(volume);
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}
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/**
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* An author-controlled id, made safe to put in a filename.
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*
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* `data-audio-group` reaches this file straight from the document — the
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* studio's `GROUP_ID_PATTERN` guards only ids the studio itself mints, and a
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* hand-authored or agent-written one is unvalidated. Interpolated raw it could
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* carry `/` or `..`, and `mkdirSync(recursive)` inside ffmpeg's own path
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* handling would then write outside `workDir`, where `bail()`'s `rmSync` never
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* cleans it up. Everything outside [A-Za-z0-9_-] collapses to `_`, and every
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* result gets a stable positional suffix so distinct ids that sanitize alike
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* cannot share one intermediate file.
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*/
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function safePathSegment(id: string, fallbackIndex: number): string {
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const cleaned = id.replace(/[^A-Za-z0-9_-]/g, "_");
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// Sanitisation is many-to-one (`bed/a` and `bed?a` both become `bed_a`).
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// The stable position keeps every authored group on a distinct temp path
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// even when their readable portions collide.
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return `${cleaned || "group"}-${fallbackIndex}`;
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}
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function formatFilterNumber(value: number): string {
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return Number(value.toFixed(6)).toString();
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}
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/** Build an FFmpeg-compatible, pitch-preserving tempo chain. */
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function buildAtempoFilter(playbackRate: number): string | null {
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let remaining = normalizePlaybackRate(playbackRate);
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if (Math.abs(remaining - 1) < 1e-9) return null;
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const stages: number[] = [];
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while (remaining < 0.5 - 1e-9) {
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stages.push(0.5);
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remaining /= 0.5;
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}
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while (remaining > 2 + 1e-9) {
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stages.push(2);
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remaining /= 2;
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}
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if (Math.abs(remaining - 1) >= 1e-9) stages.push(remaining);
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return stages.map((stage) => `atempo=${formatFilterNumber(stage)}`).join(",");
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}
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function preparedAudioOutputArgs(srcPath: string, playbackRate: number): Promise<string[]> {
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return stereoOutputArgs(srcPath).then((channelArgs) => {
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const filters: string[] = [];
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const outputArgs: string[] = [];
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if (channelArgs[0] === "-af" && channelArgs[1]) {
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filters.push(channelArgs[1]);
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} else {
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outputArgs.push(...channelArgs);
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}
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const atempo = buildAtempoFilter(playbackRate);
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if (atempo) filters.push(atempo);
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if (filters.length > 0) outputArgs.push("-af", filters.join(","));
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return outputArgs;
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});
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}
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function escapeExpressionCommas(expression: string): string {
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return expression.replace(/\\/g, "\\\\").replace(/,/g, "\\,");
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}
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function legacyFilterScriptOptionIsUnsupported(stderr: string): boolean {
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return (
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/filter_complex_script/i.test(stderr) &&
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/(?:unrecognized option|option (?:was )?not found)/i.test(stderr)
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);
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}
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/**
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* Upper bound on volume-automation keyframes folded into the FFmpeg `volume`
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* expression. The expression nests one `if(lt(...))` per keyframe, and
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* FFmpeg's expression evaluator has a finite nesting depth: past ~95 levels
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* (build-dependent — lower on some Linux ffmpeg builds) `volume=...:eval=frame`
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* fails filter-graph init, which fails the whole mix and drops the audio track
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* entirely. The 60 Hz timeline probe routinely emits 100–300 keyframes for a
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* multi-second fade (GH #1066 follow-up: a 171-keyframe GSAP fade rendered with
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* no audio). 32 segments keeps a wide safety margin and is far more resolution
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* than a piecewise-linear volume envelope needs.
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*/
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const MAX_VOLUME_SEGMENTS = 32;
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/**
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* Volume delta below which a keyframe is collinear enough to drop. Kept tight
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* (0.5% linear) so the rendered piecewise-linear envelope tracks the GSAP curve
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* the browser plays in preview to within ~0.2 dB across the audible range — well
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* under the ~1 dB loudness JND, so render stays WYSIWYG with preview. A full
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* ease-in/ease-out fade still reduces to ~25 segments, inside MAX_VOLUME_SEGMENTS.
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*/
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const VOLUME_SIMPLIFY_EPSILON = 0.005;
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// `-ac 2` uses FFmpeg's default mono-to-stereo rematrix, which attenuates a
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// mono source by 3 dB. Explicitly map front-center into both stereo channels;
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// native stereo sources have FL/FR and pass through unchanged.
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const STEREO_CHANNEL_FILTER = "pan=stereo|FL=FL+FC|FR=FR+FC";
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async function stereoOutputArgs(srcPath: string): Promise<string[]> {
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try {
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const { channels } = await extractAudioMetadata(srcPath);
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if (channels === 1) return ["-af", STEREO_CHANNEL_FILTER];
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} catch {
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// Preserve the previous FFmpeg conversion path when metadata probing fails.
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}
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return ["-ac", "2"];
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}
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/**
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* Reduce a sorted keyframe list to a perceptually-equivalent piecewise-linear
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* envelope with a bounded segment count.
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*
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* Ramer–Douglas–Peucker drops control points lying within
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* `VOLUME_SIMPLIFY_EPSILON` of the line through their neighbours (a linear fade
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* collapses to its two endpoints; an eased fade to a handful). A uniform
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* downsample backstop then bounds pathological inputs (e.g. audio-rate volume
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* oscillation) to `MAX_VOLUME_SEGMENTS`. Endpoints are always preserved so the
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* envelope still spans the full clip.
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*/
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function simplifyVolumeKeyframes(
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keyframes: { time: number; volume: number }[],
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): { time: number; volume: number }[] {
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if (keyframes.length < 3) return keyframes;
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const keep = new Array<boolean>(keyframes.length).fill(false);
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keep[0] = true;
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keep[keyframes.length - 1] = true;
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const stack: [number, number][] = [[0, keyframes.length - 1]];
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while (stack.length > 0) {
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const [startIndex, endIndex] = stack.pop()!;
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const start = keyframes[startIndex]!;
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const end = keyframes[endIndex]!;
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const span = end.time - start.time;
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let maxDistance = VOLUME_SIMPLIFY_EPSILON;
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let splitIndex = -1;
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for (let i = startIndex + 1; i < endIndex; i += 1) {
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const point = keyframes[i]!;
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const interpolated =
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span === 0
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? start.volume
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: start.volume + ((end.volume - start.volume) * (point.time - start.time)) / span;
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const distance = Math.abs(point.volume - interpolated);
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if (distance > maxDistance) {
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maxDistance = distance;
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splitIndex = i;
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}
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}
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if (splitIndex !== -1) {
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keep[splitIndex] = true;
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stack.push([startIndex, splitIndex], [splitIndex, endIndex]);
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}
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}
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const simplified = keyframes.filter((_, i) => keep[i]);
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if (simplified.length <= MAX_VOLUME_SEGMENTS) return simplified;
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const step = (simplified.length - 1) / (MAX_VOLUME_SEGMENTS - 1);
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const sampled: { time: number; volume: number }[] = [];
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for (let i = 0; i < MAX_VOLUME_SEGMENTS; i += 1) {
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const point = simplified[Math.round(i * step)]!;
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if (sampled.length === 0 || point.time > sampled.at(-1)!.time) sampled.push(point);
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}
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return sampled;
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}
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function buildVolumeExpression(track: AudioTrack, ignoreKeyframes = false): string {
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const trimDuration = track.end - track.start;
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const staticVolume = clampVolume(track.volume);
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const keyframes = (ignoreKeyframes ? [] : (track.volumeKeyframes ?? []))
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.filter((keyframe) => Number.isFinite(keyframe.time) && Number.isFinite(keyframe.volume))
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.map((keyframe) => ({
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time: Math.max(0, Math.min(trimDuration, keyframe.time - track.start)),
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volume: clampVolume(keyframe.volume),
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}))
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.sort((a, b) => a.time - b.time);
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if (keyframes.length === 0) return `volume=${formatFilterNumber(staticVolume)}`;
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if (keyframes[0]!.time > 0) {
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keyframes.unshift({ time: 0, volume: staticVolume });
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}
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const deduped: typeof keyframes = [];
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for (const keyframe of keyframes) {
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const previous = deduped.at(-1);
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if (previous && Math.abs(previous.time - keyframe.time) < 0.000001) {
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previous.volume = keyframe.volume;
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} else {
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deduped.push(keyframe);
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}
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}
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// Collapse the densely-sampled probe output to a bounded piecewise-linear
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// envelope. Without this, the nested-if expression below grows one level per
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// keyframe and overflows FFmpeg's expression evaluator (see MAX_VOLUME_SEGMENTS).
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const simplified = simplifyVolumeKeyframes(deduped);
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if (simplified.length === 1) {
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return `volume=${formatFilterNumber(simplified[0]!.volume)}`;
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}
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let expression = formatFilterNumber(simplified.at(-1)!.volume);
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for (let i = simplified.length - 2; i >= 0; i -= 1) {
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const current = simplified[i]!;
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const next = simplified[i + 1]!;
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const currentTime = formatFilterNumber(current.time);
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const nextTime = formatFilterNumber(next.time);
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const currentVolume = formatFilterNumber(current.volume);
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const span = Math.max(0.000001, next.time - current.time);
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const slope = formatFilterNumber((next.volume - current.volume) / span);
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const segment = `${currentVolume}+(${slope})*(t-${currentTime})`;
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expression = `if(lt(t,${nextTime}),${segment},${expression})`;
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}
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return `volume=${escapeExpressionCommas(expression)}:eval=frame`;
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}
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interface ExtractResult {
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success: boolean;
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outputPath: string;
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durationMs: number;
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error?: string;
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failure?: AudioProcessingFailure;
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}
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function boundedDetail(message: string, maxLength = 2_000): string {
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const redacted = message
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.replace(/\bhttps?:\/\/[^\s"'<>]+/gi, "<redacted-url>")
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.replace(/\bfile:\/\/[^\s"'<>]+/gi, "<redacted-path>")
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.replace(
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/\b[A-Za-z]:[\\/].+?(?=:\s[A-Z]|\s(?:ENOENT|EACCES|EPERM)\b|\r?$)/gm,
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"<redacted-path>",
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)
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.replace(
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/(^|[\s"'(])\/.+?(?=:\s[A-Z]|\s(?:ENOENT|EACCES|EPERM)\b|\r?$)/gm,
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"$1<redacted-path>",
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);
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return redacted.length <= maxLength ? redacted : `${redacted.slice(0, maxLength - 1)}…`;
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}
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function probeFailure(message: string, elementId: string): AudioProcessingFailure {
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const unavailable = /(?:not found|ENOENT|spawn)/i.test(message);
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const cancelled = /(?:aborted|AbortError|cancelled|canceled)/i.test(message);
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const timedOut = /(?:timed?\s*out|timeout|deadline|inactivity)/i.test(message);
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const invalidMedia =
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/(?:invalid data found|could not find codec parameters|moov atom not found|no audio stream)/i.test(
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message,
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);
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return {
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stage: "probe",
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reason: cancelled
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? "cancelled"
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: invalidMedia
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? "invalid_media"
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: unavailable
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? "ffmpeg_unavailable"
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: timedOut
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? "ffmpeg_timeout"
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: "probe_failed",
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owner: cancelled || invalidMedia ? "user" : "system",
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retryable: !cancelled && !invalidMedia && (unavailable || timedOut),
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elementId,
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detail: boundedDetail(`Audio probe failed for element ${elementId}: ${message}`),
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};
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}
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function downloadFailure(error: unknown, elementId: string): AudioProcessingFailure {
|
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const message = error instanceof Error ? error.message : String(error);
|
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const invalidSource =
|
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error instanceof UrlDownloadError
|
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? error.kind === "http_not_found" ||
|
||
error.kind === "http_rejected" ||
|
||
error.kind === "invalid_payload" ||
|
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error.kind === "cancelled"
|
||
: /(?:invalid URL|only HTTPS|private\/reserved|HTTP (?:400|401|403|404|405|410|422)\b)/i.test(
|
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message,
|
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);
|
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const retryable = error instanceof UrlDownloadError ? error.retryable : !invalidSource;
|
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return {
|
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stage: "download",
|
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reason: "download_failed",
|
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owner: invalidSource ? "user" : "system",
|
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retryable,
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elementId,
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detail: boundedDetail(`Download failed for audio element ${elementId}: ${message}`),
|
||
};
|
||
}
|
||
|
||
function ffmpegFailure(
|
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stage: Extract<AudioFailureStage, "extract" | "prepare" | "mix" | "silence">,
|
||
result: RunFfmpegResult,
|
||
elementId?: string,
|
||
): AudioProcessingFailure {
|
||
const stderr = result.stderr ?? "";
|
||
let reason: AudioProcessingFailure["reason"] = "ffmpeg_failed";
|
||
let owner: AudioProcessingFailure["owner"] = "system";
|
||
let retryable = false;
|
||
|
||
if (result.terminationReason === "abort") {
|
||
reason = "cancelled";
|
||
owner = "user";
|
||
} else if (result.terminationReason === "deadline" || result.terminationReason === "inactivity") {
|
||
reason = "ffmpeg_timeout";
|
||
retryable = true;
|
||
} else if (result.terminationReason === "spawn_error") {
|
||
reason = "ffmpeg_unavailable";
|
||
retryable = true;
|
||
} else if (
|
||
/(?:unrecognized option|option (?:was )?not found|no option name near)/i.test(stderr)
|
||
) {
|
||
reason = "ffmpeg_unsupported";
|
||
} else if (
|
||
(stage === "extract" || stage === "prepare") &&
|
||
/(?:invalid data found|could not find codec parameters|moov atom not found)/i.test(stderr)
|
||
) {
|
||
reason = "invalid_media";
|
||
owner = "user";
|
||
}
|
||
|
||
return {
|
||
stage,
|
||
reason,
|
||
owner,
|
||
retryable,
|
||
elementId,
|
||
detail: boundedDetail(
|
||
result.error?.message
|
||
? `${formatFfmpegError(result.exitCode, stderr)}: ${result.error.message}`
|
||
: formatFfmpegError(result.exitCode, stderr),
|
||
),
|
||
};
|
||
}
|
||
|
||
/** Extra samples per second inside a segment the baker cannot draw straight. */
|
||
const CURVED_SEGMENT_SAMPLES_PER_SEC = 30;
|
||
|
||
/**
|
||
* A volume lane as keyframes for the PCM baker.
|
||
*
|
||
* The baker interpolates linearly between keyframes, so a straight segment
|
||
* needs only its two ends — a simple fade stays two keyframes. A bent one is
|
||
* sampled, or the bake would quietly straighten it.
|
||
*
|
||
* Times come out in composition seconds, which is what the baker subtracts the
|
||
* track start from. Returns null when the track has no volume lane.
|
||
*/
|
||
export function volumeLaneKeyframes(
|
||
automation: { lanes: HfAutomationLane[] },
|
||
trackStart: number,
|
||
duration: number,
|
||
): AudioVolumeKeyframe[] | null {
|
||
const lane = automation.lanes.find((l) => l.target === VOLUME_TARGET);
|
||
if (!lane || lane.points.length === 0) return null;
|
||
|
||
const out: AudioVolumeKeyframe[] = [];
|
||
const push = (t: number, v: number): void => {
|
||
out.push({ time: trackStart + t, volume: v });
|
||
};
|
||
|
||
// The envelope holds its first value before the first point, rather than
|
||
// falling back to `data-volume`.
|
||
const first = lane.points[0]!;
|
||
if (first.t > 0) push(0, first.v);
|
||
|
||
for (let i = 0; i < lane.points.length; i += 1) {
|
||
const a = lane.points[i]!;
|
||
push(a.t, a.v);
|
||
const b = lane.points[i + 1];
|
||
if (!b || !a.curve) continue;
|
||
const steps = Math.max(2, Math.ceil((b.t - a.t) * CURVED_SEGMENT_SAMPLES_PER_SEC));
|
||
for (let k = 1; k < steps; k += 1) {
|
||
const t = a.t + ((b.t - a.t) * k) / steps;
|
||
push(t, sampleAutomationLane(lane, t));
|
||
}
|
||
}
|
||
|
||
// Hold the last value to the clip's end, so the baker does not ramp away
|
||
// from it toward whatever it would otherwise assume.
|
||
const last = lane.points[lane.points.length - 1]!;
|
||
if (duration > last.t) push(duration, last.v);
|
||
return out;
|
||
}
|
||
|
||
export function parseAudioElements(html: string): AudioElement[] {
|
||
const elements: AudioElement[] = [];
|
||
const { document } = parseHTML(unwrapTemplate(html));
|
||
interface AudioMediaElement extends RefResolverEl {
|
||
hasAttribute(name: string): boolean;
|
||
parentElement: AudioMediaElement | null;
|
||
}
|
||
|
||
// Shared resolver state so a relative `data-start` ("start when clip X ends")
|
||
// resolves against every clip in the composition — exactly as
|
||
// parseVideoElements does. Without this, `parseFloat("clipId")` yields NaN and
|
||
// the mixer silently drops the track (the segment renders as pure digital
|
||
// silence), even though the same reference places the *video* correctly.
|
||
const startCache = new Map<RefResolverEl, number>();
|
||
const visiting = new Set<RefResolverEl>();
|
||
const resolveStart = (el: RefResolverEl): number =>
|
||
el.getAttribute("data-start") ? resolveReferencedStart(document, el, startCache, visiting) : 0;
|
||
// `end` stays a plain numeric read (the mixer derives the real segment length
|
||
// from data-duration / natural media downstream); guard NaN so a malformed
|
||
// value never poisons the mix instead of falling back to 0.
|
||
const parseEnd = (raw: string | null): number => {
|
||
return parseStrictFiniteTimingNumber(raw) ?? 0;
|
||
};
|
||
const isHidden = (el: AudioMediaElement): boolean => {
|
||
for (let current: AudioMediaElement | null = el; current; current = current.parentElement) {
|
||
if (current.hasAttribute("data-hidden")) return true;
|
||
}
|
||
return false;
|
||
};
|
||
|
||
// Resolved once per parse. A group element carrying `data-hidden` drops
|
||
// every member from the render (RULES: mute-by-drop, never
|
||
// mute-by-volume-0) — members never enter the sub-mix.
|
||
const groupsById = new Map(
|
||
resolveAudioGroups(document).map((group) => [group.id, group] as const),
|
||
);
|
||
const memberGroupHidden = (el: AudioMediaElement): boolean => {
|
||
const groupId = memberGroupKey(el);
|
||
return groupId ? (groupsById.get(groupId)?.hidden ?? false) : false;
|
||
};
|
||
|
||
// <audio> and <video data-has-audio> tracks differ only in the emitted id
|
||
|
||
// and `type`; everything else (timing, layer, volume) is read identically.
|
||
const build = (
|
||
el: RefResolverEl,
|
||
id: string,
|
||
src: string,
|
||
type: AudioElement["type"],
|
||
): AudioElement => {
|
||
const playbackRateAttr = el.getAttribute("data-playback-rate");
|
||
const layerAttr = el.getAttribute("data-layer");
|
||
const volumeAttr = el.getAttribute("data-volume");
|
||
const fxChain = el.getAttribute(HF_AUDIO_FX_ATTR);
|
||
const automation = el.getAttribute(HF_AUDIO_AUTOMATION_ATTR);
|
||
// Audio only in v1 (matches resolveAudioGroups, which only scans
|
||
// `audio[data-audio-group]`) — a stray attribute on a <video> is inert.
|
||
const groupId = type === "audio" ? memberGroupKey(el) : null;
|
||
const group = groupId ? groupsById.get(groupId) : undefined;
|
||
return {
|
||
id,
|
||
src,
|
||
start: resolveStart(el),
|
||
end: parseEnd(el.getAttribute("data-end")),
|
||
mediaStart: readMediaStart(el),
|
||
playbackRate: normalizePlaybackRate(
|
||
playbackRateAttr ? parseFloat(playbackRateAttr) : Number.NaN,
|
||
),
|
||
layer: layerAttr ? parseInt(layerAttr) : 0,
|
||
volume: volumeAttr ? parseFloat(volumeAttr) : 1.0,
|
||
...(fxChain ? { fxChain } : {}),
|
||
...(automation ? { automation } : {}),
|
||
...(group
|
||
? {
|
||
groupId: group.id,
|
||
...(group.fxChain ? { groupFxChain: group.fxChain } : {}),
|
||
...(group.automation ? { groupAutomation: group.automation } : {}),
|
||
groupVolume: group.volume,
|
||
}
|
||
: {}),
|
||
type,
|
||
};
|
||
};
|
||
|
||
// A compiled render document stamps a document-unique render id; prefer it,
|
||
// because element ids are only unique within one composition file and the
|
||
// render document inlines many. See core's mediaRenderIds.ts.
|
||
const trackId = (el: RefResolverEl): string | null =>
|
||
el.getAttribute(MEDIA_RENDER_ID_ATTR) || el.getAttribute("id");
|
||
|
||
for (const el of document.querySelectorAll("audio[id]")) {
|
||
const id = trackId(el);
|
||
const src = resolveMediaElementSrc(el);
|
||
// `memberGroupHidden` is the group's own mute: a hidden BUS drops every
|
||
// member from the mix, the same way `isHidden` drops one track.
|
||
if (!id || !src || isHidden(el) || memberGroupHidden(el)) continue;
|
||
if (isKnownInactiveTimelineWindow(el, resolveStart(el))) continue;
|
||
elements.push(build(el, id, src, "audio"));
|
||
}
|
||
|
||
for (const el of document.querySelectorAll('video[id][data-has-audio="true"]')) {
|
||
const id = trackId(el);
|
||
const src = resolveMediaElementSrc(el);
|
||
if (!id || !src || isHidden(el)) continue;
|
||
if (isKnownInactiveTimelineWindow(el, resolveStart(el))) continue;
|
||
elements.push(build(el, `${id}-audio`, src, "video"));
|
||
}
|
||
|
||
return elements;
|
||
}
|
||
|
||
async function extractAudioFromVideo(
|
||
videoPath: string,
|
||
outputPath: string,
|
||
options?: { startTime?: number; duration?: number; playbackRate?: number },
|
||
signal?: AbortSignal,
|
||
config?: Partial<Pick<EngineConfig, "ffmpegProcessTimeout">>,
|
||
): Promise<ExtractResult> {
|
||
const ffmpegProcessTimeout = config?.ffmpegProcessTimeout ?? DEFAULT_CONFIG.ffmpegProcessTimeout;
|
||
const outputDir = dirname(outputPath);
|
||
if (!existsSync(outputDir)) mkdirSync(outputDir, { recursive: true });
|
||
|
||
const playbackRate = normalizePlaybackRate(options?.playbackRate ?? 1);
|
||
const args: string[] = [];
|
||
if (options?.startTime !== undefined) args.push("-ss", String(options.startTime));
|
||
if (options?.duration !== undefined) args.push("-t", String(options.duration * playbackRate));
|
||
args.push("-i", videoPath);
|
||
const outputArgs = await preparedAudioOutputArgs(videoPath, playbackRate);
|
||
args.push("-vn", "-acodec", "pcm_s16le", "-ar", "48000", ...outputArgs);
|
||
if (playbackRate !== 1 && options?.duration !== undefined) {
|
||
args.push("-t", String(options.duration));
|
||
}
|
||
args.push("-y", outputPath);
|
||
|
||
const result = await runFfmpeg(args, { signal, timeout: ffmpegProcessTimeout });
|
||
|
||
if (signal?.aborted) {
|
||
const failure: AudioProcessingFailure = {
|
||
stage: "cancelled",
|
||
reason: "cancelled",
|
||
owner: "user",
|
||
retryable: false,
|
||
detail: "Audio extract cancelled",
|
||
};
|
||
return {
|
||
success: false,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
error: failure.detail,
|
||
failure,
|
||
};
|
||
}
|
||
if (!result.success) {
|
||
const failure = ffmpegFailure("extract", result);
|
||
return {
|
||
success: false,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
error: failure.detail,
|
||
failure,
|
||
};
|
||
}
|
||
return { success: true, outputPath, durationMs: result.durationMs };
|
||
}
|
||
|
||
async function prepareAudioTrack(
|
||
srcPath: string,
|
||
outputPath: string,
|
||
mediaStart: number,
|
||
duration: number,
|
||
playbackRate = 1,
|
||
signal?: AbortSignal,
|
||
config?: Partial<Pick<EngineConfig, "ffmpegProcessTimeout">>,
|
||
): Promise<ExtractResult> {
|
||
const ffmpegProcessTimeout = config?.ffmpegProcessTimeout ?? DEFAULT_CONFIG.ffmpegProcessTimeout;
|
||
const outputDir = dirname(outputPath);
|
||
if (!existsSync(outputDir)) mkdirSync(outputDir, { recursive: true });
|
||
const normalizedPlaybackRate = normalizePlaybackRate(playbackRate);
|
||
const outputArgs = await preparedAudioOutputArgs(srcPath, normalizedPlaybackRate);
|
||
|
||
const args = [
|
||
"-ss",
|
||
String(mediaStart),
|
||
"-t",
|
||
String(duration * normalizedPlaybackRate),
|
||
"-i",
|
||
srcPath,
|
||
"-acodec",
|
||
"pcm_s16le",
|
||
"-ar",
|
||
"48000",
|
||
...outputArgs,
|
||
];
|
||
if (normalizedPlaybackRate !== 1) args.push("-t", String(duration));
|
||
args.push("-y", outputPath);
|
||
|
||
const result = await runFfmpeg(args, { signal, timeout: ffmpegProcessTimeout });
|
||
|
||
if (signal?.aborted) {
|
||
const failure: AudioProcessingFailure = {
|
||
stage: "cancelled",
|
||
reason: "cancelled",
|
||
owner: "user",
|
||
retryable: false,
|
||
detail: "Audio prepare cancelled",
|
||
};
|
||
return {
|
||
success: false,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
error: failure.detail,
|
||
failure,
|
||
};
|
||
}
|
||
const failure = !result.success ? ffmpegFailure("prepare", result) : undefined;
|
||
return {
|
||
success: result.success,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
error: failure?.detail,
|
||
failure,
|
||
};
|
||
}
|
||
|
||
async function generateSilence(
|
||
outputPath: string,
|
||
duration: number,
|
||
signal?: AbortSignal,
|
||
config?: Partial<Pick<EngineConfig, "ffmpegProcessTimeout">>,
|
||
): Promise<ExtractResult> {
|
||
const ffmpegProcessTimeout = config?.ffmpegProcessTimeout ?? DEFAULT_CONFIG.ffmpegProcessTimeout;
|
||
const outputDir = dirname(outputPath);
|
||
if (!existsSync(outputDir)) mkdirSync(outputDir, { recursive: true });
|
||
|
||
const args = [
|
||
"-f",
|
||
"lavfi",
|
||
"-i",
|
||
"anullsrc=r=48000:cl=stereo",
|
||
"-t",
|
||
String(duration),
|
||
"-acodec",
|
||
"pcm_s16le",
|
||
"-y",
|
||
outputPath,
|
||
];
|
||
|
||
const result = await runFfmpeg(args, { signal, timeout: ffmpegProcessTimeout });
|
||
|
||
if (signal?.aborted) {
|
||
const failure: AudioProcessingFailure = {
|
||
stage: "cancelled",
|
||
reason: "cancelled",
|
||
owner: "user",
|
||
retryable: false,
|
||
detail: "Silence generation cancelled",
|
||
};
|
||
return {
|
||
success: false,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
error: failure.detail,
|
||
failure,
|
||
};
|
||
}
|
||
const failure = !result.success ? ffmpegFailure("silence", result) : undefined;
|
||
return {
|
||
success: result.success,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
error: failure?.detail,
|
||
failure,
|
||
};
|
||
}
|
||
|
||
async function mixAudioTracks(
|
||
tracks: AudioTrack[],
|
||
outputPath: string,
|
||
totalDuration: number,
|
||
signal?: AbortSignal,
|
||
config?: Partial<Pick<EngineConfig, "ffmpegProcessTimeout" | "audioGain">>,
|
||
): Promise<MixResult> {
|
||
const ffmpegProcessTimeout = config?.ffmpegProcessTimeout ?? DEFAULT_CONFIG.ffmpegProcessTimeout;
|
||
const masterOutputGain = config?.audioGain ?? DEFAULT_CONFIG.audioGain;
|
||
|
||
if (tracks.length === 0) {
|
||
const result = await generateSilence(outputPath, totalDuration, signal, config);
|
||
return {
|
||
success: result.success,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
tracksProcessed: 0,
|
||
error: result.error,
|
||
failures: result.failure ? [result.failure] : undefined,
|
||
};
|
||
}
|
||
|
||
const outputDir = dirname(outputPath);
|
||
if (!existsSync(outputDir)) mkdirSync(outputDir, { recursive: true });
|
||
|
||
const buildFilterComplex = (ignoreAutomation: boolean): string => {
|
||
const filterParts: string[] = [];
|
||
tracks.forEach((track, i) => {
|
||
const delayMs = Math.round(track.start * 1000);
|
||
// A clip's own audio ends at `end`, but an FX tail is still decaying past
|
||
// it. Trimming at the boundary is what cut every reverb short; the final
|
||
// atrim below still holds the mix to the composition's length, so a tail
|
||
// can run over what follows but never past the end of the video.
|
||
const trimDuration = track.end - track.start + (track.tailSeconds ?? 0);
|
||
const volumeFilter = buildVolumeExpression(track, ignoreAutomation);
|
||
// `apad` then `atrim` is the portable pad-to-length shape: PR #2769 moved
|
||
// off `apad=whole_dur=` because some FFmpeg builds reject that option
|
||
// outright ("Error applying option 'whole_dur': Option not found").
|
||
// But on FFmpeg 5.x through 8.0.x the samples `apad` appends carry
|
||
// timestamps the following `atrim` misreads, so a delayed branch lands at
|
||
// t=0 and, once four or more branches are mixed, the last one disappears
|
||
// entirely. `asetpts=N/SR/TB` renumbers the padded stream from the sample
|
||
// count before the trim reads it, which fixes the misplacement while
|
||
// keeping the filter set every build supports. Verified correct on 4.2.7,
|
||
// 7.0.2, an 8.x nightly and 8.1.1; the un-reset form is wrong on the
|
||
// middle two.
|
||
filterParts.push(
|
||
`[${i}:a]atrim=0:${formatFilterNumber(trimDuration)},${volumeFilter},adelay=${delayMs}|${delayMs},apad,asetpts=N/SR/TB,atrim=0:${formatFilterNumber(totalDuration)}[a${i}]`,
|
||
);
|
||
});
|
||
|
||
const mixInputs = tracks.map((_, i) => `[a${i}]`).join("");
|
||
const mixFilter = `${mixInputs}amix=inputs=${tracks.length}:duration=longest:dropout_transition=0[mixed]`;
|
||
// amix divides output by inputs count (default normalize=true). Multiply master
|
||
// gain by track count so per-track volumes authored in data-volume are preserved.
|
||
const compensatedGain = masterOutputGain * tracks.length;
|
||
const postMixGainFilter = `[mixed]volume=${formatFilterNumber(compensatedGain)}[out]`;
|
||
return [...filterParts, mixFilter, postMixGainFilter].join(";");
|
||
};
|
||
|
||
// A large track count (100+) makes the inline `-filter_complex <string>`
|
||
// argument scale linearly with track count until it exceeds the OS
|
||
// command-line length limit — spawn ENAMETOOLONG, seen in practice at 146
|
||
// tracks — even though every individual filter segment is short. FFmpeg's
|
||
// file-valued filter options read the same graph from disk instead,
|
||
// sidestepping the argv limit for the one component of this command line
|
||
// that actually grows with the composition. FFmpeg deprecated
|
||
// `-filter_complex_script` in favour of `-/filter_complex`, then removed the
|
||
// alias from nightly builds; older stable builds do not understand the new
|
||
// spelling. Prefer the legacy spelling for broad compatibility and retry
|
||
// only when FFmpeg explicitly says that option is unavailable.
|
||
const runMix = async (ignoreAutomation: boolean) => {
|
||
const inputs: string[] = [];
|
||
tracks.forEach((track) => inputs.push("-i", track.srcPath));
|
||
const scriptDir = mkdtempSync(join(outputDir, ".filter-complex-"));
|
||
const scriptPath = join(scriptDir, "graph.txt");
|
||
const fd = openSync(scriptPath, "wx", 0o600);
|
||
try {
|
||
writeFileSync(fd, buildFilterComplex(ignoreAutomation));
|
||
} finally {
|
||
closeSync(fd);
|
||
}
|
||
const args = [
|
||
...inputs,
|
||
"-filter_complex_script",
|
||
scriptPath,
|
||
"-map",
|
||
"[out]",
|
||
"-acodec",
|
||
"aac",
|
||
"-b:a",
|
||
"192k",
|
||
"-t",
|
||
String(totalDuration),
|
||
"-y",
|
||
outputPath,
|
||
];
|
||
try {
|
||
const legacyResult = await runFfmpeg(args, { signal, timeout: ffmpegProcessTimeout });
|
||
if (legacyResult.success || !legacyFilterScriptOptionIsUnsupported(legacyResult.stderr)) {
|
||
return legacyResult;
|
||
}
|
||
const currentArgs = [...args];
|
||
currentArgs[currentArgs.indexOf("-filter_complex_script")] = "-/filter_complex";
|
||
return await runFfmpeg(currentArgs, { signal, timeout: ffmpegProcessTimeout });
|
||
} finally {
|
||
rmSync(scriptDir, { recursive: true, force: true });
|
||
}
|
||
};
|
||
|
||
let result = await runMix(false);
|
||
|
||
// Defense in depth: volume automation is folded into an FFmpeg `volume`
|
||
// expression whose evaluator limits are build-dependent (see
|
||
// MAX_VOLUME_SEGMENTS). If that ever fails the mix, retry once without the
|
||
// automation so the track renders at its base volume rather than being
|
||
// dropped from the output entirely — a missing fade beats missing audio.
|
||
let degradedAutomation = false;
|
||
const hasAutomation = tracks.some((track) => (track.volumeKeyframes?.length ?? 0) > 0);
|
||
if (!result.success && !signal?.aborted && hasAutomation) {
|
||
const retry = await runMix(true);
|
||
if (retry.success) {
|
||
result = retry;
|
||
degradedAutomation = true;
|
||
}
|
||
}
|
||
|
||
if (signal?.aborted) {
|
||
return {
|
||
success: false,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
tracksProcessed: 0,
|
||
error: "Audio mix cancelled",
|
||
failures: [
|
||
{
|
||
stage: "cancelled",
|
||
reason: "cancelled",
|
||
owner: "user",
|
||
retryable: false,
|
||
detail: "Audio mix cancelled",
|
||
},
|
||
],
|
||
};
|
||
}
|
||
if (!result.success) {
|
||
const failure = ffmpegFailure("mix", result);
|
||
return {
|
||
success: false,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
tracksProcessed: 0,
|
||
error: failure.detail,
|
||
failures: [failure],
|
||
};
|
||
}
|
||
return {
|
||
success: true,
|
||
outputPath,
|
||
durationMs: result.durationMs,
|
||
tracksProcessed: tracks.length,
|
||
error: degradedAutomation
|
||
? "Volume automation exceeded this ffmpeg build's expression limits; rendered at base volume"
|
||
: undefined,
|
||
};
|
||
}
|
||
|
||
/**
|
||
* Verified against the real binary, because the wording is the whole contract:
|
||
* ffmpeg 8.1.1 emits `Error applying option 'X' to filter 'amix': Option not
|
||
* found`, which "option not found" matches. Only pre-4.4 libavfilter's
|
||
* `Option 'normalize' not found` phrasing sits outside the first test — and
|
||
* that build predates `normalize` existing at all, so it would fail for the
|
||
* right reason anyway. A review pass read this as dead and it is not.
|
||
*/
|
||
function groupNormalizeOptionUnsupported(stderr: string): boolean {
|
||
return (
|
||
/normalize/i.test(stderr) &&
|
||
/(?:unrecognized option|option (?:was )?not found|no option name)/i.test(stderr)
|
||
);
|
||
}
|
||
|
||
/**
|
||
* Sub-mix one group's members into a single PCM WAV at full composition
|
||
* length — the same per-input treatment `mixAudioTracks` gives every track
|
||
* (atrim, volume, adelay, `apad` — RULES 6), writing PCM instead of AAC so the
|
||
* result can feed straight into `applyAudioFxChain` (which reads raw WAV
|
||
* samples, not a decoded container).
|
||
*
|
||
* The gain law is the whole reason this is a separate function and not a call
|
||
* into `mixAudioTracks`: `plans/spikes/amix-nesting-spike.sh` measured that
|
||
* compensating a nested amix by anything other than ITS OWN input count is a
|
||
* silent +2.499 dB (20·log10(4/3) for a 3-of-4-track case) — audible, and
|
||
* invisible to every existing test because it only shows up in export, never
|
||
* preview. `normalize=0` nulls exactly against a flat mix with no
|
||
* compensation at all and is preferred; the manual per-own-count fallback
|
||
* only runs when this ffmpeg build's `amix` rejects the option.
|
||
*/
|
||
async function mixGroupMembers(
|
||
memberTracks: AudioTrack[],
|
||
outputPath: string,
|
||
totalDuration: number,
|
||
signal?: AbortSignal,
|
||
config?: Partial<Pick<EngineConfig, "ffmpegProcessTimeout">>,
|
||
): Promise<{ success: boolean; error?: string; degradedAutomation?: boolean }> {
|
||
const ffmpegProcessTimeout = config?.ffmpegProcessTimeout ?? DEFAULT_CONFIG.ffmpegProcessTimeout;
|
||
const outputDir = dirname(outputPath);
|
||
if (!existsSync(outputDir)) mkdirSync(outputDir, { recursive: true });
|
||
|
||
const buildInputFilters = (ignoreKeyframes: boolean) =>
|
||
memberTracks.map((track, i) => {
|
||
const delayMs = Math.round(track.start * 1000);
|
||
const trimDuration = track.end - track.start + (track.tailSeconds ?? 0);
|
||
const volumeFilter = buildVolumeExpression(track, ignoreKeyframes);
|
||
// Same `asetpts=N/SR/TB` as the master mix above, for the same reason and
|
||
// on the same builds: these are delayed branches padded to length and then
|
||
// amix'd, so without the renumbering a delayed member lands at t=0 and a
|
||
// group of four or more loses its last one.
|
||
return `[${i}:a]atrim=0:${formatFilterNumber(trimDuration)},${volumeFilter},adelay=${delayMs}|${delayMs},apad,asetpts=N/SR/TB,atrim=0:${formatFilterNumber(totalDuration)}[a${i}]`;
|
||
});
|
||
const mixInputs = memberTracks.map((_, i) => `[a${i}]`).join("");
|
||
|
||
const runOnce = async (
|
||
useNormalize: boolean,
|
||
ignoreKeyframes = false,
|
||
): Promise<RunFfmpegResult> => {
|
||
const inputFilters = buildInputFilters(ignoreKeyframes);
|
||
const mixFilter = useNormalize
|
||
? `${mixInputs}amix=inputs=${memberTracks.length}:duration=longest:dropout_transition=0:normalize=0[out]`
|
||
: // Every member is padded and trimmed to totalDuration above, and
|
||
// dropout_transition=0 keeps all N inputs active for that whole span.
|
||
// amix's default normalize therefore divides by exactly N throughout;
|
||
// compensate by THIS group's own member count — never the render's
|
||
// global track count.
|
||
`${mixInputs}amix=inputs=${memberTracks.length}:duration=longest:dropout_transition=0[mixed];[mixed]volume=${formatFilterNumber(memberTracks.length)}[out]`;
|
||
const filterComplex = [...inputFilters, mixFilter].join(";");
|
||
const scriptDir = mkdtempSync(join(outputDir, ".group-filter-complex-"));
|
||
const scriptPath = join(scriptDir, "graph.txt");
|
||
const fd = openSync(scriptPath, "wx", 0o600);
|
||
try {
|
||
writeFileSync(fd, filterComplex);
|
||
} finally {
|
||
closeSync(fd);
|
||
}
|
||
try {
|
||
const inputs: string[] = [];
|
||
memberTracks.forEach((track) => inputs.push("-i", track.srcPath));
|
||
const args = [
|
||
...inputs,
|
||
"-filter_complex_script",
|
||
scriptPath,
|
||
"-map",
|
||
"[out]",
|
||
// Float, not pcm_s16le: `normalize=0` sums the members at unity, so any
|
||
// over-unity sum hard-clipped at ±1 in the intermediate — BEFORE the
|
||
// group's FX chain and its fader ran. Pulling the group down, or the
|
||
// Giant preset's compressor, then operated on distortion. Preview
|
||
// cannot reproduce it (its bus is float), and it only shows up in the
|
||
// export. Both readers downstream take float: `readWav` (format 3) and
|
||
// `applyVolumeEnvelopeToWav`.
|
||
"-acodec",
|
||
"pcm_f32le",
|
||
"-ar",
|
||
"48000",
|
||
"-t",
|
||
String(totalDuration),
|
||
"-y",
|
||
outputPath,
|
||
];
|
||
const legacyResult = await runFfmpeg(args, { signal, timeout: ffmpegProcessTimeout });
|
||
if (legacyResult.success || !legacyFilterScriptOptionIsUnsupported(legacyResult.stderr)) {
|
||
return legacyResult;
|
||
}
|
||
const currentArgs = [...args];
|
||
currentArgs[currentArgs.indexOf("-filter_complex_script")] = "-/filter_complex";
|
||
return await runFfmpeg(currentArgs, { signal, timeout: ffmpegProcessTimeout });
|
||
} finally {
|
||
rmSync(scriptDir, { recursive: true, force: true });
|
||
}
|
||
};
|
||
|
||
let useNormalize = true;
|
||
let result = await runOnce(useNormalize);
|
||
if (!result.success && groupNormalizeOptionUnsupported(result.stderr)) {
|
||
useNormalize = false;
|
||
result = await runOnce(useNormalize);
|
||
}
|
||
|
||
// The same defence `mixAudioTracks` has, which this forked without: a
|
||
// member's volume automation becomes an ffmpeg `volume` expression whose
|
||
// evaluator limits are build-dependent, so a dense envelope can fail the
|
||
// whole run. Ungrouped, that track degrades to base volume with a warning;
|
||
// grouped, it took the entire composition's audio down with it.
|
||
let degradedAutomation = false;
|
||
const hasAutomation = memberTracks.some((track) => (track.volumeKeyframes?.length ?? 0) > 0);
|
||
if (!result.success && !signal?.aborted && hasAutomation) {
|
||
const retry = await runOnce(useNormalize, true);
|
||
if (retry.success) {
|
||
result = retry;
|
||
degradedAutomation = true;
|
||
}
|
||
}
|
||
|
||
if (signal?.aborted) return { success: false, error: "Group sub-mix cancelled" };
|
||
if (!result.success)
|
||
return { success: false, error: formatFfmpegError(result.exitCode, result.stderr) };
|
||
return { success: true, degradedAutomation };
|
||
}
|
||
|
||
export async function processCompositionAudio(
|
||
elements: AudioElement[],
|
||
baseDir: string,
|
||
workDir: string,
|
||
outputPath: string,
|
||
totalDuration: number,
|
||
signal?: AbortSignal,
|
||
config?: Partial<Pick<EngineConfig, "ffmpegProcessTimeout" | "audioGain">>,
|
||
compiledDir?: string,
|
||
): Promise<MixResult> {
|
||
const startMs = Date.now();
|
||
const tracks: AudioTrack[] = [];
|
||
const failures: AudioProcessingFailure[] = [];
|
||
// Grouped members are diverted here instead of `tracks` during element
|
||
// processing, then summed into one processed track per group before the
|
||
// final mix — see the group sub-mix pass below. `groupMeta` takes the
|
||
// first-seen chain/automation/volume for a group id: every member of the
|
||
// same group carries an identical copy (both resolved from the same
|
||
// `resolveAudioGroups` call in `parseAudioElements`), so any one works.
|
||
const groupTracks = new Map<string, AudioTrack[]>();
|
||
const groupMeta = new Map<string, { fxChain?: string; automation?: string; volume: number }>();
|
||
|
||
if (!existsSync(workDir)) mkdirSync(workDir, { recursive: true });
|
||
|
||
// Every element's work races under Promise.all, which rejects on the first
|
||
// failure without waiting for its siblings. A fatal FX error therefore has to
|
||
// be able to abort the in-flight ffmpeg runs before the finally-block removes
|
||
// workDir out from under them. Chained off the caller's signal so external
|
||
// cancellation still behaves as before.
|
||
//
|
||
// Every child that can outlive a sibling's failure has to be given THIS
|
||
// signal, not the caller's: the trim, the video extract and the download all
|
||
// took `signal`, so `internalController.abort()` cancelled nothing and the
|
||
// `rmSync(workDir)` on the next line ran while their ffmpeg children were
|
||
// still writing into it.
|
||
const internalController = new AbortController();
|
||
const effectiveSignal = internalController.signal;
|
||
if (signal) {
|
||
if (signal.aborted) internalController.abort();
|
||
else signal.addEventListener("abort", () => internalController.abort(), { once: true });
|
||
}
|
||
|
||
await Promise.all(
|
||
elements.map(async (element) => {
|
||
if (effectiveSignal.aborted) {
|
||
failures.push({
|
||
stage: "cancelled",
|
||
reason: "cancelled",
|
||
owner: "user",
|
||
retryable: false,
|
||
elementId: element.id,
|
||
detail: boundedDetail(`Cancelled audio element ${element.id}`),
|
||
});
|
||
return;
|
||
}
|
||
try {
|
||
let srcPath = element.src;
|
||
if (!isHttpUrl(srcPath)) {
|
||
// Same browser-vs-filesystem path semantics as videos — see
|
||
// resolveProjectRelativeSrc in videoFrameExtractor for the full why.
|
||
srcPath = resolveProjectRelativeSrc(element.src, baseDir, compiledDir);
|
||
}
|
||
|
||
if (isHttpUrl(srcPath)) {
|
||
try {
|
||
srcPath = await downloadToTemp(
|
||
srcPath,
|
||
workDir,
|
||
undefined,
|
||
effectiveSignal,
|
||
undefined,
|
||
{
|
||
onTelemetry: writeUrlDownloadTelemetry,
|
||
},
|
||
);
|
||
} catch (err: unknown) {
|
||
failures.push(downloadFailure(err, element.id));
|
||
return;
|
||
}
|
||
}
|
||
|
||
if (!existsSync(srcPath)) {
|
||
failures.push({
|
||
stage: "source",
|
||
reason: "source_not_found",
|
||
owner: "user",
|
||
retryable: false,
|
||
elementId: element.id,
|
||
detail: boundedDetail(`Source not found for audio element ${element.id}`),
|
||
});
|
||
return;
|
||
}
|
||
|
||
// STUDIO-5433: an audio src that resolved to a text document (an
|
||
// unresolved nested-composition preview URL, or a 403/404 body served
|
||
// with a 200) never reaches the probe below when the element carries an
|
||
// authored duration or `loop`. It then fails inside ffmpeg as
|
||
// `prepare/ffmpeg_failed` with owner "system" — an authoring bug paged
|
||
// as a platform fault, after every frame has already been captured.
|
||
if (await isNotMediaPayload(srcPath)) {
|
||
failures.push({
|
||
stage: "source",
|
||
reason: "invalid_media",
|
||
owner: "user",
|
||
retryable: false,
|
||
elementId: element.id,
|
||
detail: boundedDetail(
|
||
`Audio element ${element.id} source is a text document (HTML/XML/JSON), not media`,
|
||
),
|
||
});
|
||
return;
|
||
}
|
||
|
||
// Fallback: if no duration was specified, probe the actual file
|
||
if (element.end - element.start <= 0) {
|
||
let metadata;
|
||
try {
|
||
metadata = await extractAudioMetadata(srcPath);
|
||
} catch (err: unknown) {
|
||
failures.push(
|
||
probeFailure(err instanceof Error ? err.message : String(err), element.id),
|
||
);
|
||
return;
|
||
}
|
||
const effectiveDuration =
|
||
(metadata.durationSeconds - element.mediaStart) /
|
||
normalizePlaybackRate(element.playbackRate ?? 1);
|
||
element.end =
|
||
element.start + (effectiveDuration > 0 ? effectiveDuration : metadata.durationSeconds);
|
||
}
|
||
|
||
let audioSrcPath = srcPath;
|
||
if (element.type === "video") {
|
||
const extractedPath = join(workDir, `${element.id}-extracted.wav`);
|
||
const extractResult = await extractAudioFromVideo(
|
||
srcPath,
|
||
extractedPath,
|
||
{
|
||
startTime: element.mediaStart,
|
||
duration: element.end - element.start,
|
||
playbackRate: element.playbackRate,
|
||
},
|
||
effectiveSignal,
|
||
config,
|
||
);
|
||
if (!extractResult.success) {
|
||
failures.push(
|
||
extractResult.failure
|
||
? { ...extractResult.failure, elementId: element.id }
|
||
: {
|
||
stage: "extract",
|
||
reason: "ffmpeg_failed",
|
||
owner: "system",
|
||
retryable: false,
|
||
elementId: element.id,
|
||
detail: boundedDetail(`Audio extract failed for element ${element.id}`),
|
||
},
|
||
);
|
||
return;
|
||
}
|
||
audioSrcPath = extractedPath;
|
||
} else {
|
||
const trimmedPath = join(workDir, `${element.id}-trimmed.wav`);
|
||
const prepResult = await prepareAudioTrack(
|
||
srcPath,
|
||
trimmedPath,
|
||
element.mediaStart,
|
||
element.end - element.start,
|
||
element.playbackRate,
|
||
effectiveSignal,
|
||
config,
|
||
);
|
||
if (!prepResult.success) {
|
||
failures.push(
|
||
prepResult.failure
|
||
? { ...prepResult.failure, elementId: element.id }
|
||
: {
|
||
stage: "prepare",
|
||
reason: "ffmpeg_failed",
|
||
owner: "system",
|
||
retryable: false,
|
||
elementId: element.id,
|
||
detail: boundedDetail(`Audio prepare failed for element ${element.id}`),
|
||
},
|
||
);
|
||
return;
|
||
}
|
||
audioSrcPath = trimmedPath;
|
||
}
|
||
|
||
// Apply the track's FX chain to the dry, trimmed audio, before volume
|
||
// automation is baked in: effects should see the raw signal, and the
|
||
// envelope belongs on their output. A missing or broken chain is fatal
|
||
// for the whole mix rather than a per-track warning — quietly rendering
|
||
// the dry signal ships a mix that sounds plausible and is wrong.
|
||
const automation = element.automation
|
||
? resolveAutomation(
|
||
parseAutomation(element.automation),
|
||
element.fxChain ? parseAudioFxChain(element.fxChain) : undefined,
|
||
)
|
||
: null;
|
||
|
||
// Computed before the chain runs, not after: the FX pass bakes the
|
||
// envelope into its float output so the duck lands before the ±1 clamp
|
||
// in writeWav, instead of after it.
|
||
//
|
||
// A volume lane supersedes keyframes probed from the timeline: the two
|
||
// would fight, and the lane is the explicit one. `lint` warns when a
|
||
// track carries both.
|
||
const laneKeyframes = automation
|
||
? volumeLaneKeyframes(automation, element.start, element.end - element.start)
|
||
: null;
|
||
const envelopeKeyframes = laneKeyframes ?? element.volumeKeyframes;
|
||
const envelope =
|
||
envelopeKeyframes && envelopeKeyframes.length > 0
|
||
? {
|
||
keyframes: envelopeKeyframes,
|
||
trackStart: element.start,
|
||
baseVolume: element.volume ?? 1.0,
|
||
}
|
||
: null;
|
||
|
||
let bakedEnvelope = false;
|
||
let tailSeconds = 0;
|
||
if (element.fxChain) {
|
||
// The chain is serialised into the attribute, the same way colour
|
||
// grading carries its config, so there is no side-car file to find,
|
||
// resolve or lose.
|
||
const chain = parseAudioFxChain(element.fxChain);
|
||
// The rendered WAV is longer than the input by exactly this much, so
|
||
// the mix has to be told to let it through.
|
||
tailSeconds = chainTailSeconds(chain, automation ?? undefined);
|
||
const fxResult = await applyAudioFxChain(
|
||
audioSrcPath,
|
||
chain,
|
||
join(workDir, `${element.id}-fx.wav`),
|
||
{
|
||
trackId: element.id,
|
||
signal: effectiveSignal,
|
||
...(automation ? { automation } : {}),
|
||
...(envelope ? { envelope } : {}),
|
||
},
|
||
);
|
||
audioSrcPath = fxResult.path;
|
||
bakedEnvelope = fxResult.envelopeBaked;
|
||
}
|
||
|
||
// Primary volume-automation path for a track the FX pass did not bake:
|
||
// multiply the envelope into the PCM samples (sample-accurate, no
|
||
// keyframe ceiling). If the WAV isn't the expected 16-bit PCM, fall
|
||
// back to the ffmpeg expression path by leaving the keyframes on the
|
||
// track for buildVolumeExpression to handle.
|
||
if (envelope && !bakedEnvelope) {
|
||
bakedEnvelope = applyVolumeEnvelopeToWav(
|
||
audioSrcPath,
|
||
envelope.keyframes,
|
||
envelope.trackStart,
|
||
envelope.baseVolume,
|
||
);
|
||
}
|
||
const track: AudioTrack = {
|
||
id: element.id,
|
||
srcPath: audioSrcPath,
|
||
start: element.start,
|
||
end: element.end,
|
||
mediaStart: element.mediaStart,
|
||
duration: element.end - element.start,
|
||
// Gain is already in the samples when baked, so mix at unity.
|
||
volume: bakedEnvelope ? 1.0 : (element.volume ?? 1.0),
|
||
volumeKeyframes: bakedEnvelope ? undefined : (envelopeKeyframes ?? undefined),
|
||
...(tailSeconds > 0 ? { tailSeconds } : {}),
|
||
};
|
||
|
||
// A grouped member keeps every bit of its OWN processing above
|
||
// (FX, envelope) exactly like an ungrouped track — it just lands in
|
||
// the group's bucket instead of the flat list, to be summed into one
|
||
// processed bus below rather than mixed directly.
|
||
if (element.groupId) {
|
||
const bucket = groupTracks.get(element.groupId);
|
||
if (bucket) bucket.push(track);
|
||
else groupTracks.set(element.groupId, [track]);
|
||
if (!groupMeta.has(element.groupId)) {
|
||
groupMeta.set(element.groupId, {
|
||
...(element.groupFxChain ? { fxChain: element.groupFxChain } : {}),
|
||
...(element.groupAutomation ? { automation: element.groupAutomation } : {}),
|
||
volume: element.groupVolume ?? 1,
|
||
});
|
||
}
|
||
} else {
|
||
tracks.push(track);
|
||
}
|
||
} catch (err: unknown) {
|
||
// An FX failure is fatal for the whole mix. Every other failure mode
|
||
// degrades gracefully — the track drops and siblings continue — but
|
||
// substituting the dry signal for a processed one ships a render that
|
||
// sounds plausible and is not what was authored.
|
||
if (err instanceof AudioFxRenderError) throw err;
|
||
failures.push({
|
||
stage: "internal",
|
||
reason: "internal",
|
||
owner: "system",
|
||
retryable: false,
|
||
elementId: element.id,
|
||
detail: boundedDetail(
|
||
`Audio processing failed for element ${element.id}: ${
|
||
err instanceof Error ? err.message : String(err)
|
||
}`,
|
||
),
|
||
});
|
||
}
|
||
}),
|
||
).catch((err: unknown) => {
|
||
// Promise.all rejected on the first fatal failure without waiting for its
|
||
// siblings; abort them so their ffmpeg stops before workDir disappears.
|
||
internalController.abort();
|
||
try {
|
||
rmSync(workDir, { recursive: true, force: true });
|
||
} catch {
|
||
/* ignore */
|
||
}
|
||
throw err;
|
||
});
|
||
|
||
// Never turn a per-track preparation failure into a successful partial mix.
|
||
// The producer only surfaces audio failures when `success` is false; mixing
|
||
// the remaining tracks made the omitted cue indistinguishable from a valid
|
||
// render unless someone manually audited that exact audio window.
|
||
const bail = (): MixResult => {
|
||
try {
|
||
rmSync(workDir, { recursive: true, force: true });
|
||
} catch {
|
||
/* ignore */
|
||
}
|
||
return {
|
||
success: false,
|
||
outputPath,
|
||
durationMs: Date.now() - startMs,
|
||
tracksProcessed: tracks.length,
|
||
error: boundedDetail(
|
||
`Audio processing failed: ${failures.map((failure) => failure.detail).join(", ")}`,
|
||
),
|
||
failures,
|
||
};
|
||
};
|
||
if (failures.length > 0) return bail();
|
||
|
||
// Sub-mix each group into one processed bus (design doc §1.3), then fold it
|
||
// into the flat track list as a single AudioTrack — everything downstream
|
||
// (the final mixAudioTracks call) never has to know groups exist. Group
|
||
// clock is composition time (offset 0): a group has no `data-start` of its
|
||
// own, and members are already delayed to their composition positions
|
||
// inside the sub-mix, so the group WAV's t=0 IS composition time.
|
||
const groupsDegradedAutomation: string[] = [];
|
||
let groupIndex = -1;
|
||
for (const [groupId, memberTracks] of groupTracks) {
|
||
groupIndex += 1;
|
||
const meta = groupMeta.get(groupId);
|
||
if (!meta) continue;
|
||
const pathId = safePathSegment(groupId, groupIndex);
|
||
const groupWavPath = join(workDir, `group-${pathId}.wav`);
|
||
// Same contract the per-element loop above gives: a malformed `data-fx-chain`
|
||
// or `data-automation` on a BUS threw straight out of processCompositionAudio,
|
||
// bypassing the MixResult/failures[] shape the caller handles and skipping
|
||
// `bail()`, so the temp dir leaked too. An AudioFxRenderError stays fatal
|
||
// for the same reason it is fatal per element: shipping the dry signal in
|
||
// place of a processed one sounds plausible and is not what was authored.
|
||
try {
|
||
const subMix = await mixGroupMembers(
|
||
memberTracks,
|
||
groupWavPath,
|
||
totalDuration,
|
||
effectiveSignal,
|
||
config,
|
||
);
|
||
if (!subMix.success) {
|
||
failures.push({
|
||
stage: "mix",
|
||
reason: "ffmpeg_failed",
|
||
owner: "system",
|
||
retryable: false,
|
||
elementId: groupId,
|
||
detail: boundedDetail(
|
||
`Group sub-mix failed for group ${groupId}: ${subMix.error ?? "unknown"}`,
|
||
),
|
||
});
|
||
continue;
|
||
}
|
||
if (subMix.degradedAutomation) groupsDegradedAutomation.push(groupId);
|
||
|
||
// Composition-time automation (offset 0, duration totalDuration) — same
|
||
// resolve/lane/bake path a member uses, just anchored at the group clock
|
||
// instead of a clip's own start.
|
||
const automation = meta.automation
|
||
? resolveAutomation(
|
||
parseAutomation(meta.automation),
|
||
meta.fxChain ? parseAudioFxChain(meta.fxChain) : undefined,
|
||
)
|
||
: null;
|
||
const laneKeyframes = automation ? volumeLaneKeyframes(automation, 0, totalDuration) : null;
|
||
const envelope =
|
||
laneKeyframes && laneKeyframes.length > 0
|
||
? { keyframes: laneKeyframes, trackStart: 0, baseVolume: meta.volume }
|
||
: null;
|
||
|
||
let groupSrcPath = groupWavPath;
|
||
let bakedEnvelope = false;
|
||
if (meta.fxChain) {
|
||
const chain = parseAudioFxChain(meta.fxChain);
|
||
const fxResult = await applyAudioFxChain(
|
||
groupSrcPath,
|
||
chain,
|
||
join(workDir, `group-${pathId}-fx.wav`),
|
||
{
|
||
trackId: groupId,
|
||
signal: effectiveSignal,
|
||
...(automation ? { automation } : {}),
|
||
...(envelope ? { envelope } : {}),
|
||
},
|
||
);
|
||
groupSrcPath = fxResult.path;
|
||
bakedEnvelope = fxResult.envelopeBaked;
|
||
}
|
||
if (envelope && !bakedEnvelope) {
|
||
bakedEnvelope = applyVolumeEnvelopeToWav(
|
||
groupSrcPath,
|
||
envelope.keyframes,
|
||
envelope.trackStart,
|
||
envelope.baseVolume,
|
||
);
|
||
}
|
||
|
||
// `end` is already the render's totalDuration, so the outer mix's own
|
||
// atrim-to-totalDuration clips this track exactly the same way it would
|
||
// an ungrouped one whose clip ran to the end of the render — a group's FX
|
||
// tail gets the same "never past the end of the video" treatment member
|
||
// tails get, for free, with no separate tailSeconds bookkeeping needed.
|
||
tracks.push({
|
||
id: groupId,
|
||
srcPath: groupSrcPath,
|
||
start: 0,
|
||
end: totalDuration,
|
||
mediaStart: 0,
|
||
duration: totalDuration,
|
||
volume: bakedEnvelope ? 1.0 : meta.volume,
|
||
// Same fallback an ungrouped track gets: when the envelope could not be
|
||
// baked into the samples, hand the keyframes to the outer mix's volume
|
||
// expression instead of dropping the group's automation on the floor.
|
||
...(bakedEnvelope || !laneKeyframes?.length ? {} : { volumeKeyframes: laneKeyframes }),
|
||
});
|
||
} catch (err: unknown) {
|
||
if (err instanceof AudioFxRenderError) throw err;
|
||
failures.push({
|
||
stage: "mix",
|
||
reason: "internal",
|
||
owner: "system",
|
||
retryable: false,
|
||
elementId: groupId,
|
||
detail: boundedDetail(
|
||
`Audio processing failed for group ${groupId}: ${
|
||
err instanceof Error ? err.message : String(err)
|
||
}`,
|
||
),
|
||
});
|
||
}
|
||
}
|
||
if (failures.length > 0) return bail();
|
||
|
||
const mixResult = await mixAudioTracks(tracks, outputPath, totalDuration, signal, config);
|
||
|
||
try {
|
||
rmSync(workDir, { recursive: true, force: true });
|
||
} catch {
|
||
/* ignore */
|
||
}
|
||
|
||
// A group whose sub-mix had to drop member automation reports it the same
|
||
// way mixAudioTracks reports its own degradation: on a SUCCESSFUL result, so
|
||
// the render ships and the caller can still say what was lost.
|
||
const degradedNote =
|
||
groupsDegradedAutomation.length > 0
|
||
? `Volume automation exceeded this ffmpeg build's expression limits in group(s) ${groupsDegradedAutomation.join(", ")}; rendered at base volume`
|
||
: undefined;
|
||
|
||
return {
|
||
...mixResult,
|
||
durationMs: Date.now() - startMs,
|
||
// Both, when both degraded. `mixResult.error ?? degradedNote` reported only
|
||
// the outer mix and dropped the one that names which GROUPS lost their
|
||
// members' automation — two different losses, and the operator needs to
|
||
// hear about the one they can act on.
|
||
error: [mixResult.error, degradedNote].filter(Boolean).join("; ") || undefined,
|
||
};
|
||
}
|