llama-stack-mirror/llama_stack/ui/lib/audio-utils.ts

type RecordAudioType = {
  (stream: MediaStream): Promise<Blob>;
  stop: () => void;
  currentRecorder?: MediaRecorder;
};

export const recordAudio = (function (): RecordAudioType {
  const func = async function recordAudio(stream: MediaStream): Promise<Blob> {
    try {
      const mediaRecorder = new MediaRecorder(stream, {
        mimeType: "audio/webm;codecs=opus",
      });
      const audioChunks: Blob[] = [];

      return new Promise((resolve, reject) => {
        mediaRecorder.ondataavailable = event => {
          if (event.data.size > 0) {
            audioChunks.push(event.data);
          }
        };

        mediaRecorder.onstop = () => {
          const audioBlob = new Blob(audioChunks, { type: "audio/webm" });
          resolve(audioBlob);
        };

        mediaRecorder.onerror = () => {
          reject(new Error("MediaRecorder error occurred"));
        };

        mediaRecorder.start(1000);
        (func as RecordAudioType).currentRecorder = mediaRecorder;
      });
    } catch (error) {
      const errorMessage =
        error instanceof Error ? error.message : "Unknown error occurred";
      throw new Error("Failed to start recording: " + errorMessage);
    }
  };

  (func as RecordAudioType).stop = () => {
    const recorder = (func as RecordAudioType).currentRecorder;
    if (recorder && recorder.state !== "inactive") {
      recorder.stop();
    }
    delete (func as RecordAudioType).currentRecorder;
  };

  return func as RecordAudioType;
})();