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intercom/MediaStreamRecorder

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A cross-browser implementation to record audio/video streams:

  1. MediaStreamRecorder can record both audio and video in single WebM file on Firefox.
  2. MediaStreamRecorder can record audio as WAV and video as either WebM or animated gif on Chrome.

MediaStreamRecorder is useful in scenarios where you're planning to submit/upload recorded blobs in realtime to the server! You can get blobs after specific time-intervals.

Experiment Name Demo Source Code
Audio Recording Demo Source
Video Recording Demo Source
Gif Recording Demo Source
MultiStreamRecorder Demo Demo Source

There is a similar project: RecordRTC! Demo - Documentation

How to link scripts?

You can install scripts using NPM:

npm install msr

Then link single/standalone "MediaStreamRecorder.js" file:

<script src="./node_modules/msr/MediaStreamRecorder.js"> </script>

Otherwise, you can "directly" link standalone file from CDN:

<script src="https://cdn.webrtc-experiment.com/MediaStreamRecorder.js"> </script>

Otherwise, you can link specific files:

Record audio+video in Firefox in single WebM

<script src="https://cdn.webrtc-experiment.com/MediaStreamRecorder.js"> </script>
<script>
var mediaConstraints = {
    audio: !!navigator.mozGetUserMedia, // don't forget audio!
    video: true                         // don't forget video!
};

navigator.getUserMedia(mediaConstraints, onMediaSuccess, onMediaError);

function onMediaSuccess(stream) {
    var mediaRecorder = new MediaStreamRecorder(stream);
    mediaRecorder.mimeType = 'video/webm';
    mediaRecorder.ondataavailable = function (blob) {
        // POST/PUT "Blob" using FormData/XHR2
        var blobURL = URL.createObjectURL(blob);
        document.write('<a href="' + blobURL + '">' + blobURL + '</a>');
    };
    mediaRecorder.start(3000);
}

function onMediaError(e) {
    console.error('media error', e);
}
</script>

Record audio+video in Chrome

MultiStreamRecorder.js records both audio/video and returns both blobs in single ondataavailable event.

<script src="https://cdn.webrtc-experiment.com/MediaStreamRecorder.js"> </script>
<script>
var mediaConstraints = {
    audio: true,
    video: true
};

navigator.getUserMedia(mediaConstraints, onMediaSuccess, onMediaError);

function onMediaSuccess(stream) {
    var multiStreamRecorder = new MultiStreamRecorder(stream);
    multiStreamRecorder.video = yourVideoElement; // to get maximum accuracy
    multiStreamRecorder.audioChannels = 1;
    multiStreamRecorder.ondataavailable = function (blobs) {
        // blobs.audio
        // blobs.video
    };
    multiStreamRecorder.start(3 * 1000);
}

function onMediaError(e) {
    console.error('media error', e);
}
</script>

Record only audio in Chrome/Firefox

<script src="https://cdn.webrtc-experiment.com/MediaStreamRecorder.js"> </script>
var mediaConstraints = {
    audio: true
};

navigator.getUserMedia(mediaConstraints, onMediaSuccess, onMediaError);

function onMediaSuccess(stream) {
    var mediaRecorder = new MediaStreamRecorder(stream);
    mediaRecorder.mimeType = 'audio/ogg';
    mediaRecorder.audioChannels = 1;
    mediaRecorder.ondataavailable = function (blob) {
        // POST/PUT "Blob" using FormData/XHR2
        var blobURL = URL.createObjectURL(blob);
        document.write('<a href="' + blobURL + '">' + blobURL + '</a>');
    };
    mediaRecorder.start(3000);
}

function onMediaError(e) {
    console.error('media error', e);
}

Record only-video in chrome

<script src="https://cdn.webrtc-experiment.com/MediaStreamRecorder.js"> </script>
<script>
var mediaConstraints = {
    video: true
};

navigator.getUserMedia(mediaConstraints, onMediaSuccess, onMediaError);

function onMediaSuccess(stream) {
    var mediaRecorder = new MediaStreamRecorder(stream);
    mediaRecorder.mimeType = 'video/webm';
	
    // for gif recording
    // mediaRecorder.mimeType = 'image/gif';
	
    mediaRecorder.width = 320;
    mediaRecorder.height = 240;
	
    mediaRecorder.ondataavailable = function (blob) {
        // POST/PUT "Blob" using FormData/XHR2
        var blobURL = URL.createObjectURL(blob);
        document.write('<a href="' + blobURL + '">' + blobURL + '</a>');
    };
    mediaRecorder.start(3000);
}

function onMediaError(e) {
    console.error('media error', e);
}
</script>

How to manually stop recordings?

mediaRecorder.stop();

How to upload recorded files using PHP?

PHP code:

<?php
foreach(array('video', 'audio') as $type) {
    if (isset($_FILES["${type}-blob"])) {
        
		$fileName = $_POST["${type}-filename"];
        $uploadDirectory = "uploads/$fileName";
        
        if (!move_uploaded_file($_FILES["${type}-blob"]["tmp_name"], $uploadDirectory)) {
            echo("problem moving uploaded file");
        }
		
		echo($uploadDirectory);
    }
}
?>

JavaScript Code:

var fileType = 'video'; // or "audio"
var fileName = 'ABCDEF.webm';  // or "wav" or "ogg"

var formData = new FormData();
formData.append(fileType + '-filename', fileName);
formData.append(fileType + '-blob', blob);

xhr('save.php', formData, function (fileURL) {
    window.open(fileURL);
});

function xhr(url, data, callback) {
    var request = new XMLHttpRequest();
    request.onreadystatechange = function () {
        if (request.readyState == 4 && request.status == 200) {
            callback(location.href + request.responseText);
        }
    };
    request.open('POST', url);
    request.send(data);
}

API Documentation

audioChannels

It is an integer value that accepts either 1 or 2. "1" means record only left-channel and skip right-one. The default value is "2".

mediaRecorder.audioChannels = 1;

bufferSize

You can set following audio-bufferSize values: 0, 256, 512, 1024, 2048, 4096, 8192, and 16384. "0" means: let chrome decide the device's default bufferSize. Default value is "2048".

mediaRecorder.bufferSize = 0;

sampleRate

Default "sampleRate" value is "44100". Currently you can't modify sample-rate in windows that's why this property isn't yet exposed to public API.

It accepts values only in range: 22050 to 96000

// set sampleRate for NON-windows systems
mediaRecorder.sampleRate = 96000;

video

It is recommended to pass your HTMLVideoElement to get most accurate result.

videoRecorder.video = yourHTMLVideoElement;
videoRecorder.onStartedDrawingNonBlankFrames = function() {
    // record audio here to fix sync issues
    // Note: MultiStreamRecorder auto handles audio sync issues.
    videoRecorder.clearOldRecordedFrames(); // clear all blank frames
    audioRecorder.start(interval);
};

canvas

Using this property, you can pass video resolutions:

mediaRecorder.canvas = {
    width: 1280,
    height: 720
};

videoWidth and videoHeight

You can stretch video to specific width/height:

mediaRecorder.videoWidth  = 1280;
mediaRecorder.videoHeight = 720;

clearOldRecordedFrames

This method allows you clear current video-frames. You can use it to remove blank-frames.

videoRecorder.video = yourHTMLVideoElement;
videoRecorder.onStartedDrawingNonBlankFrames = function() {
    videoRecorder.clearOldRecordedFrames(); // clear all blank frames
    audioRecorder.start(interval);
};

stop

This method allows you stop entire recording process.

mediaRecorder.stop();

start

This method takes "interval" as the only argument and it starts recording process:

mediaRecorder.start(5 * 1000); // it takes milliseconds

ondataavailable

This event is fired according to your interval and "stop" method.

mediaRecorder.ondataavailable = function(blob) {
    POST_to_Server(blob);
};

onstop

This event is fired when recording is stopped, either by invoking "stop" method or in case of any unexpected error:

mediaRecorder.onstop = function() {
    // recording has been stopped.
};

mimeType

This property allows you set output media type:

// video:
videoRecorder.mimeType = 'video/webm';
videoRecorder.mimeType = 'video/mp4';

// audio:
audioRecorder.mimeType = 'audio/ogg';
audioRecorder.mimeType = 'audio/wav';

// gif:
gifRecorder.mimeType = 'image/gif';

Browser Support

Browser Support
Firefox Stable / Aurora / Nightly
Google Chrome Stable / Canary / Beta / Dev
Opera Stable / NEXT
Android Chrome / Firefox / Opera

Contributors

  1. Muaz Khan
  2. neizerth
  3. andersaloof

License

MediaStreamRecorder.js library is released under MIT licence.