declare interface MediaStreamTrackGenerator<T extends (VideoFrame | AudioData)> extends MediaStreamTrack {
  writable: WritableStream<T>
}

declare const MediaStreamTrackGenerator: {
  prototype: MediaStreamTrackGenerator<VideoFrame | AudioData>
  new <T extends 'video' | 'audio'>(options: {
    kind: T
  }): T extends 'video' ? MediaStreamTrackGenerator<VideoFrame> : MediaStreamTrackGenerator<AudioData>
}

declare interface MediaStreamTrackProcessor<T extends (VideoFrame | AudioData)> {
  readable: ReadableStream<T>
}

declare const MediaStreamTrackProcessor: {
  prototype: MediaStreamTrackProcessor<VideoFrame | AudioData>
  new (options: {
    track: MediaStreamTrack
  })
}