mediastream-to-webm

Converts MediaStreams to live WebM streams. Currently only for Chrome.

Allows you to send video/audio as a single outgoing data stream to many peers.

Features

• Packages webm clusters and headers into standalone chunks that don't require the entire stream.
• Fixes MSE problems with timestamp gaps.
• Abstracts away recording and source buffers.

Install

var MediaStreamToWebm = require('mediastream-to-webm')

<script src="dist/mediastream-to-webm.js" />

Usage

// Wrap your MediaStream into an encoder
var encodedStream = MediaStreamToWebm.EncodedStream(mediaStream)
 
// The encoded stream is a ReadableStream
encodedStream.pipe(socket1) 
encodedStream.pipe(socket2) // pipe as many times as you want, at any time, without worrying about the structure of the stream
encodedStream.pipe(socket2)
// ...

var decodedStream = MediaStreamToWebm.DecodedStream()
socket.pipe(decodedStream) // pipe the encoded stream into the decoded
 
// The buffered video element is available for us to watch!
var video = decodedStream.videoElement
video.autoplay = true
video.oncanplay = function () {
    video.play()
}
document.body.appendChild(video) 

API

MediaStreamToWebm.EncodedStream(mediaStream, opts)

Encode a MediaStream into a webm data stream.

mediaStream - The input MediaStream you want to broadcast.

opts - Options object. Default is:

{
    interval: 10,
    mimeType: 'video/webm; codecs="opus,vp8"'
}

MediaStreamToWebm.DecodedStream(opts)

Decode an encoded webm data stream. Decoded data will be buffered into a video element.

opts - Options object. Default is:

{
    videoElement: null, // specify an existing video element
    mimeType: 'video/webm; codecs="opus,vp8"'
}

DecodedStream.videoElement

The video element that will be buffered with the decoded webm stream.

Notes

• Currently only works on Chrome (Firefox refuses to accept a webm stream from their own MediaRecorder...)
• This module has additional overhead for live streaming. If you want just want a prerecorded stream, use media-recorder-stream.
• Headers are sent with every chunk and this packaged needs to be decoded. You won't be able to pass the data stream directly into a webm player.
• Less efficient and versatile than sending MediaStreams over WebRTC. This "dumb" video stream is not meant to be a replacement for the adaptive bitrate, network-aware SRTP protocol used by WebRTC.