Function detectFormat

packages/cli/src/whisper/normalize.ts:37–43

(filePath: string)

 * Detect the format of a transcript file from its extension and content.
 */
export function detectFormat(filePath: string): TranscriptFormat {
  const ext = extname(filePath).toLowerCase();
  if (ext === ".srt") return "srt";
  if (ext === ".vtt") return "vtt";
  if (ext === ".json") return detectJsonFormat(JSON.parse(readFileSync(filePath, "utf-8")));
  throw new Error(`Unsupported transcript file extension: ${ext}. Use .json, .srt, or .vtt`);
}

function detectJsonFormat(raw: unknown): TranscriptFormat {
  if (raw && typeof raw === "object" && !Array.isArray(raw)) {