feat(media-use): transcription (parakeet), transcript-cut, audio-duck editing tools

2026-09-11 14:50:02 +00:00 · 2026-07-06 23:41:35 -04:00
parent 5fe957363d
commit ac0153cb30
11 changed files with 1255 additions and 2 deletions
@@ -0,0 +1,121 @@
+#!/usr/bin/env node
+
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+import { parseArgs } from "node:util";
+import { duckKeyframes, speechSpans } from "./lib/duck.mjs";
+import { track } from "./lib/telemetry.mjs";
+
+const { values: args } = parseArgs({
+  options: {
+    meta: { type: "string" },
+    target: { type: "string" },
+    duck: { type: "string", default: "0.25" },
+    attack: { type: "string", default: "0.15" },
+    release: { type: "string", default: "0.4" },
+    "merge-gap": { type: "string", default: "0.6" },
+    sequential: { type: "boolean", default: false },
+    gap: { type: "string", default: "0" },
+    offsets: { type: "string" },
+    composition: { type: "string" },
+    json: { type: "boolean", default: false },
+    help: { type: "boolean", short: "h", default: false },
+  },
+  strict: true,
+});
+
+if (args.help) {
+  console.log(`media-use audio-duck — generate GSAP volume ducking keyframes
+
+Usage:
+  node audio-duck.mjs --meta audio_meta.json --target "#bgm"
+
+Options:
+  --meta          audio_meta.json or JSON word transcript
+  --target        GSAP selector for the background audio element
+  --duck          Duck multiplier (default: 0.25)
+  --attack        Duck-in duration seconds (default: 0.15)
+  --release       Restore duration seconds (default: 0.4)
+  --merge-gap     Bridge speech gaps smaller than this many seconds (default: 0.6)
+  --sequential    Place multi-line meta back to back at composition time
+  --gap           Extra seconds between sequential lines (default: 0)
+  --offsets       Explicit placement, "l1=0,l2=3.4" (voice id = start seconds)
+  --composition   Read target data-volume from this HTML file
+  --json          Output { spans, keyframes }
+  --help, -h      Show this help`);
+  process.exit(0);
+}
+
+try {
+  run();
+  await track("media_use_duck", { sequential: !!args.sequential });
+} catch (err) {
+  if (args.json) console.log(JSON.stringify({ ok: false, error: err.message }));
+  else console.error(`error: ${err.message}`);
+  process.exit(1);
+}
+
+function run() {
+  if (!args.meta || !args.target) throw new Error("--meta and --target are required");
+  const meta = JSON.parse(readFileSync(resolve(args.meta), "utf8"));
+  const target = args.target;
+  const baseVolume = readBaseVolume(args.composition, target);
+  const offsets = args.offsets
+    ? Object.fromEntries(
+        args.offsets.split(",").map((pair) => {
+          const [id, t] = pair.split("=");
+          return [id.trim(), Number(t)];
+        }),
+      )
+    : undefined;
+  const spans = speechSpans(meta, {
+    mergeGap: Number(args["merge-gap"]),
+    sequential: args.sequential,
+    gap: Number(args.gap),
+    offsets,
+  });
+  const keyframes = duckKeyframes(spans, {
+    duck: Number(args.duck),
+    attack: Number(args.attack),
+    release: Number(args.release),
+    baseVolume,
+  });
+
+  if (args.json) {
+    console.log(JSON.stringify({ spans, keyframes }));
+    return;
+  }
+
+  console.log(
+    `// auto-duck: ${target} under narration (generated; base volume ${fmt(baseVolume)})`,
+  );
+  for (const keyframe of keyframes) {
+    console.log(
+      `tl.to(${JSON.stringify(target)}, { volume: ${fmt(keyframe.volume)}, duration: ${fmt(
+        keyframe.duration,
+      )} }, ${fmt(keyframe.time)});`,
+    );
+  }
+}
+
+function readBaseVolume(composition, target) {
+  if (!composition || !target.startsWith("#")) return 1;
+  const id = target.slice(1);
+  const html = readFileSync(resolve(composition), "utf8");
+  // ponytail: regex is enough here because this only reads one attribute from
+  // one user-authored composition element, not arbitrary HTML.
+  const tag = html.match(new RegExp(`<[^>]*\\bid=["']${escapeRegExp(id)}["'][^>]*>`, "i"))?.[0];
+  const raw = tag?.match(/\bdata-volume=["']([^"']+)["']/i)?.[1];
+  const volume = Number(raw);
+  return Number.isFinite(volume) ? volume : 1;
+}
+
+function escapeRegExp(value) {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
+function fmt(n) {
+  return Number(n)
+    .toFixed(3)
+    .replace(/\.?0+$/, "");
+}