MS Teams Online Transcript Downloader

script.js

// Open the transcript, then paste into DevTools Console.
// In Teams, select "RecapxPlatIframe" (xplatplugins.aspx) in the Console's frame dropdown first.
(async () => {
  const DOWNLOAD_JSON = true; // false: TXT only
  const info = window.g_fileInfo || {};
  const resources = performance.getEntriesByType("resource").map(r => r.name).reverse();
  const urls = [...new Set([
    ...resources.filter(u => /\/media\/transcripts\/[^/?]+\/streamContent(?:\?|$)/i.test(u)),
    ...resources.filter(u => /\/cdnmedia\/transcripts\/?(?:\?|$)/i.test(u)),
    info.spItemTranscriptsContentCdnUrl,
    info.spItemTranscriptsContentUrl
  ].filter(Boolean))];
  if (!urls.length) throw new Error(
    "Open the transcript first. In Teams, select RecapxPlatIframe in the Console's frame dropdown."
  );

  const parse = text => {
    text = text.replace(/^\uFEFF/, "").trim();
    try {
      const json = JSON.parse(text);
      if (json.entries?.length) return json;
    } catch {}
    if (!/^WEBVTT(?:\s|$)/i.test(text)) return null;
    const entries = [];
    for (const block of text.split(/\r?\n\s*\r?\n/)) {
      const lines = block.split(/\r?\n/);
      const i = lines.findIndex(line => line.includes("-->"));
      const timing = lines[i]?.match(/(\S+)\s+-->\s+(\S+)/);
      if (!timing) continue;
      const cue = lines.slice(i + 1).join(" ");
      const voice = cue.match(/<v(?:\.[^\s>]+)?\s+([^>]+)>/i);
      const decoded = document.createElement("textarea");
      decoded.innerHTML = cue.replace(/<[^>]*>/g, "");
      if (decoded.value.trim()) entries.push({
        startOffset: timing[1], endOffset: timing[2],
        speakerDisplayName: voice?.[1] || "?", text: decoded.value.trim()
      });
    }
    return entries.length ? { entries } : null;
  };

  const utf8 = new TextDecoder();
  const base64 = s => Uint8Array.from(atob(s), c => c.charCodeAt(0));
  let transcript;
  for (const url of urls) {
    try {
      const response = await fetch(url, {
        credentials: "include", signal: AbortSignal.timeout(15000)
      });
      if (!response.ok) continue;
      const bytes = await response.arrayBuffer();
      transcript = parse(utf8.decode(bytes));
      if (!transcript && info.EncKey) {
        const enc = typeof info.EncKey === "string" ? JSON.parse(info.EncKey) : info.EncKey;
        const key = await crypto.subtle.importKey("raw", base64(enc.Key), "AES-CBC", false, ["decrypt"]);
        transcript = parse(utf8.decode(await crypto.subtle.decrypt({ name: "AES-CBC", iv: base64(enc.IV) }, key, bytes)));
      }
      if (transcript) break;
    } catch {}
  }
  if (!transcript) throw new Error("Could not load the transcript. Reload the page, open the transcript and try again.");

  const seconds = value => {
    if (typeof value === "number") return value;
    const iso = String(value || "").match(/^PT(?:(\d+(?:\.\d+)?)H)?(?:(\d+(?:\.\d+)?)M)?(?:(\d+(?:\.\d+)?)S)?$/i);
    return iso ? (Number(iso[1] || 0) * 3600 + Number(iso[2] || 0) * 60 + Number(iso[3] || 0))
      : String(value || "0").replace(",", ".").split(":").reduce((n, part) => n * 60 + Number(part), 0);
  };
  const time = value => {
    const n = Math.round(seconds(value) * 1000);
    return [Math.floor(n / 3600000), Math.floor(n / 60000) % 60, Math.floor(n / 1000) % 60]
      .map(n => String(n).padStart(2, "0")).join(":") + (n % 1000 ? `.${String(n % 1000).padStart(3, "0")}` : "");
  };
  const entries = [...transcript.entries].sort((a, b) => seconds(a.startOffset) - seconds(b.startOffset));
  const txt = entries.map(e => `[${time(e.startOffset)}] ${e.speakerDisplayName || e.speakerName || e.speaker || "?"}: ${String(e.text || e.eventData?.text || "").replace(/\s+/g, " ").trim()}`).join("\n");
  const name = (info.name || document.title || "transcript")
    .replace(/\.(mp4|mov|mkv|webm|vtt).*$/i, "").replace(/[\\/:*?"<>|]/g, "-").trim().slice(0, 120) || "transcript";
  const save = (ext, text, type) => {
    const a = document.createElement("a");
    a.href = URL.createObjectURL(new Blob([text], { type }));
    a.download = `${name}-transcript.${ext}`;
    document.body.appendChild(a);
    a.click();
    a.remove();
    setTimeout(() => URL.revokeObjectURL(a.href), 30000);
  };
  save("txt", txt, "text/plain;charset=utf-8");
  if (DOWNLOAD_JSON) {
    await new Promise(resolve => setTimeout(resolve, 350));
    save("json", JSON.stringify(transcript, null, 2), "application/json");
  }
  console.info(`Downloaded ${entries.length} transcript entries.`);
})().catch(console.error);