[Proposal] Body.mediaStream(), Body.mediaStreamTrack()

Problem

Video:

Must use HTMLMediaElement and captureStream(), or WebRTC to get a MediaStream representation of the media resource including a video track.

Audio:

Must use HTMLMediaElement and captureStream(), WebRTC or Web Audio API to get a MediaStream representation of the media resource including a video track.

Solution

Add mediaStream() and mediaStreamTrack() to Body mixin of Fetch

async function fetchMediaStreamTrack(audioSrc) {
  const request = await fetch(audioSrc);
  const mediaStreamTrack = await request.mediaStreamTrack();
}

async function fetchMediaStreamTrack(videoSrc) {
  const request = await fetch(videoSrc);
  const mediaStream = await request.mediaStream();
}

This addition means that HTMLVideoElement, HTMLAudioElement, WebRTC transceiver, Web Audio API are not directly and exclusively needed (at the front-end) to stream media (fetch() is defined in Worker, Worklet).