Video

meowcaller-js supports H.264 video in Annex B format. Video support is less mature than audio — signaling works but the media send path is not fully wired.

Sending video

call.sendVideo(accessUnit)

Send an H.264 access unit (one or more NAL units in Annex B format) to the remote peer.

// Send a raw H.264 frame
call.sendVideo(h264Frame);

Receiving video

call.receiveVideo(sink)

Set a sink to receive incoming video frames.

import { VideoSinkFunc } from 'meowcaller-js';

call.receiveVideo(VideoSinkFunc((au) => {
  // au: Uint8Array containing H.264 Annex B data
  console.log('video frame:', au.length, 'bytes');
}));

Video sink adapters

VideoSinkFunc(fn)

Create a video sink from a callback.

import { VideoSinkFunc } from 'meowcaller-js';

const sink = VideoSinkFunc((au) => {
  // au is a Uint8Array with H.264 Annex B data
  processFrame(au);
});

call.receiveVideo(sink);

AnnexBRecorder(path)

Record incoming H.264 video to a .h264 file in Annex B format. The file can be played with ffplay or muxed with ffmpeg.

import { AnnexBRecorder } from 'meowcaller-js';

const recorder = await AnnexBRecorder('output.h264');
call.receiveVideo(recorder);

// When the call ends:
await recorder.close();

The recorder returns an object with:

H.264 depacketizer

The H264Depacketizer class parses Annex B byte streams into individual NAL units.

import { H264Depacketizer } from 'meowcaller-js/src/rtp.js';

const depacketizer = new H264Depacketizer();
const nalus = depacketizer.Depacketize(annexBData);

for (const nalu of nalus) {
  // each nalu is a Uint8Array containing one NAL unit (without start code)
  const naluType = nalu[0] & 0x1F;
  console.log('NALU type:', naluType);
}

NAL unit types

Video state events

call.onVideoState((vs) => {
  console.log('video active:', vs.Active);
  console.log('upgrade requested:', vs.Upgrade);
});

Limitations

• Video TX is not wired up in the media pipeline — sendVideo will throw
• No VP8/VP9 support, only H.264
• No simulcast or SVC
• The depacketizer handles single NALU and FU-A fragmentation only