MediaRecorder.MediaRecorder()

The MediaRecorder() constructor creates a new MediaRecorder object.

Syntax

var m = new MediaRecorder(stream, options);

Parameters

stream

The MediaStream that will be recorded (generated, for example, from a getUserMedia.)

options Optional

A dictionary object that can contain the following properties:

• mimeType: The mime type you want to use as the recording container for the new MediaRecorder. Applications can check in advance if this mimeType by calling MediaRecorder.isMimeTypeSupported().
• audioBitsPerSecond: The chosen bitrate for the audio component of the media.
• videoBitsPerSecond: The chosen bitrate for the video component of the media.
• bitsPerSecond: The chosen bitrate for the audio and video components of the media. This can be specified instead of the above two properties. If this is specified along with one or the other of the above properties, this will be used for the one that isn't specified.

Note: If bits per second values are not specified for video and/or audio, the default adopted for video is 2.5Mbps, while the audio default is adaptive, dependant on the sample rate and number of channels.

Example

...


if (navigator.getUserMedia) {
  console.log('getUserMedia supported.');

  var constraints = { audio: true, video: true };
  var chunks = [];

  var onSuccess = function(stream) {
    var options = {
      audioBitsPerSecond : 128000,
      videoBitsPerSecond : 2500000,
      mimeType : 'video/mp4'
    }
    var mediaRecorder = new MediaRecorder(stream,options);
    m = mediaRecorder;

...

Specifications

Browser compatibility

[1] The initial Firefox OS implementation only supported audio recording.

See also

• Using the MediaRecorder API
• Web Dictaphone: MediaRecorder + getUserMedia + Web Audio API visualization demo, by Chris Mills (source on Github.)
• simpl.info MediaStream Recording demo, by Sam Dutton.
• Navigator.getUserMedia