add transceiver to mediaConnection

[vimavis]

Solve the following problems:

• When creating a call where user A (creates the call) does not have video but has audio and user B has video and audio, user A does not see the video of user B.

• When creating a call where user A (creates the call) has no audio but video and user B has video and audio, user A does not hear user B's audio.

[rs-duongnt1]

@vimavis Nice, Same problem :)

[afrokick]

You can create empty streams(or empty tracks) to achieve the same result:

export function createEmptyAudioTrack() {
  const ctx = new AudioContext();
  const oscillator = ctx.createOscillator();

  const dst = oscillator.connect(ctx.createMediaStreamDestination());

  const track = dst.stream.getAudioTracks()[0];

  return Object.assign(track, { enabled: false });
};

export function createEmptyVideoTrack({ width, height }) {
  const canvas = Object.assign(document.createElement('canvas'), { width, height });
  canvas.getContext('2d')!.fillRect(0, 0, width, height);

  const stream = canvas.captureStream();
  const track = stream.getVideoTracks()[0];

  return Object.assign(track, { enabled: false });
};

//... in your code
const emptyStream = new MediaStream([createEmptyAudioTrack(), createEmptyVideoTrack({width:400,height:300})]);