Function extractAudioMetadata

packages/engine/src/utils/ffprobe.ts:351–389

(filePath: string)

export const extractVideoMetadata = extractMediaMetadata;

export async function extractAudioMetadata(filePath: string): Promise<AudioMetadata> {
  const cached = audioMetadataCache.get(filePath);
  if (cached) return cached;

  const probePromise = (async (): Promise<AudioMetadata> => {
    const stdout = await runFfprobe([
      "-v",
      "quiet",
      "-print_format",
      "json",
      "-show_format",
      "-show_streams",
      filePath,
    ]);
    const output = parseProbeJson(stdout);
    const audioStream = output.streams.find((s) => s.codec_type === "audio");
    if (!audioStream) throw new Error("[FFmpeg] No audio stream found");

    const durationSeconds = output.format.duration ? parseFloat(output.format.duration) : 0;
    const streamDuration = audioStream.duration ? parseFloat(audioStream.duration) : undefined;

    return {
      durationSeconds,
      streamDurationSeconds: streamDuration && streamDuration > 0 ? streamDuration : undefined,
      sampleRate: audioStream.sample_rate ? parseInt(audioStream.sample_rate) : 44100,
      channels: audioStream.channels || 2,
      audioCodec: audioStream.codec_name || "unknown",
      bitrate: output.format.bit_rate ? parseInt(output.format.bit_rate) : undefined,
    };
  })();

  audioMetadataCache.set(filePath, probePromise);
  probePromise.catch(() => {
    if (audioMetadataCache.get(filePath) === probePromise) {
      audioMetadataCache.delete(filePath);
    }
  });
  return probePromise;
}

export interface KeyframeAnalysis {
  avgIntervalSeconds: number;