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    2.0.3 • Public • Published

    Build Status Maintenance license


    jMuxer - a simple javascript mp4 muxer that works in both browser and node environment. It is communication protocol agnostic and it is intended to play media files on the browser with the help of the media source extension. It also can export mp4 on the node environment. It expects raw H264 video data and/or AAC audio data in ADTS container as an input.

    Live Demo

    Click here to view a working demo

    Click here to play a h264 file online

    How to use?

    A distribution version is available on dist folder.

      <script type="text/javascript" src="dist/jmuxer.min.js"></script>
      var jmuxer = new JMuxer(option);

    Available options are:

    node - String ID of a video tag / Reference of the HTMLVideoElement. Required field for browsers.

    mode - Available values are: both, video and audio. Default is both

    flushingTime - Buffer flushing time in milliseconds. Default value is 1500 milliseconds.

    maxDelay - Maximum delay time in milliseconds. Default value is 500 milliseconds.

    clearBuffer - true/false. Either it will clear played media buffer automatically or not. Default is true.

    fps - Optional value. Frame rate of the video if it is known/fixed value. It will be used to find frame duration if chunk duration is not available with provided media data.

    readFpsFromTrack - true/false. Will read FPS from MP4 track data instead of using (above) fps value. Default is false.

    onReady - function. Will be called once MSE is ready.

    onError - function. Will be fired if jMuxer encounters any buffer error.

    debug - true/false. Will print debug log in browser console. Default is false.

    Complete example:

       <script type="text/javascript" src="dist/jmuxer.min.js"></script>
       <video id="player"></video>
           var jmuxer = new JMuxer({
               node: 'player',
               mode: 'both', /* available values are: both, audio and video */
               debug: false
          /* Now feed media data using feed method. audio and video is buffer data and duration is in milliseconds */
             audio: audio,
             video: video,
             duration: duration

    Media dataObject may have following properties:

    video - h264 buffer

    audio - AAC buffer

    duration - duration in milliseconds of the provided chunk. If duration is not provided, it will calculate frame duration wtih the provided frame rate (fps).

    ES6 Example:

    Install module through npm

    npm install --save jmuxer
    import JMuxer from 'jmuxer';
    const jmuxer = new JMuxer({
                  node: 'player',
                  debug: true
     /* Now feed media data using feed method. audio and video is buffer data and duration is in milliseconds */
          audio: audio,
          video: video,
          duration: duration

    Node Example:

    Install module through npm

    npm install --save jmuxer
    const JMuxer = require('jmuxer');
    const jmuxer = new JMuxer({
        debug: true
    Stream in Object mode. Please check the example file for more details
    let h264_feeder = getFeederStreamSomehow();
    let http_or_ws_or_any = getWritterStreamSomehow();

    Available Methods

    Name Parameter Remark
    feed data object object properites may have audio, video and duration. At least one media property i.e audio or video must be provided. If no duration is provided, it will calculate duration based on fps value
    createStream - Get a writeable stream to feed buffer. Available on NodeJS only
    reset - Reset the jmuxer and start over
    destroy - Destroy the jmuxer instance and release the resources

    Typescript definition

    npm install --save @types/jmuxer


    compatible with browsers supporting MSE with 'video/MP4. it is supported on:

    • Chrome for Android 34+
    • Chrome for Desktop 34+
    • Firefox for Android 41+
    • Firefox for Desktop 42+
    • IE11+ for Windows 8.1+
    • Edge for Windows 10+
    • Opera for Desktop
    • Safari for Mac 8+

    Demo Server and player example

    A simple node server and some demo media data are available in the example directory. In the example, each chunk/packet is consist of 4 bytes of header and the payload following the header. The first two bytes of the header contain the chunk duration and remaining two bytes contain the audio data length. Packet format is shown in the image below:

    Packet format

    2 bytes 2 bytes
    Duration (ms) Audio Data Length Audio Data (AAC) Video Data (H264)

    A step guideline to obtain above the packet format from your mp4 file using ffmpeg:

    1. Spliting video into 2 seconds chunks: ffmpeg -i input.mp4 -c copy -map 0 -segment_time 2 -f segment %03d.mp4
    2. Extracting h264 for all chunks: for f in *.mp4; do ffmpeg -i "$f" -vcodec copy -an -bsf:v h264_mp4toannexb "${f:0:3}.h264"; done
    3. Extracting audio for all chunks: for f in *.mp4; do ffmpeg -i "$f" -acodec copy -vn "${f:0:3}.aac"; done
    4. Extracting duration for all chunks: for f in *.mp4; do ffprobe "$f" -show_format 2>&1 | sed -n 's/duration=//p'; done


    How to run example?

    Demo files are available in example directory. For running the example, first run the node server by following command:

    cd example

    node server.js

    then, visit example/index.html page using any webserver.

    Player Example for raw h264 only

    Assuming you are still in example directory. Now run followngs:

    node h264.js

    then, visit example/h264.html page using any webserver.

    How to build?

    A distribution version is available inside dist directory. However, if you need to build, you can do as follows:

    1. git clone
    2. cd jmuxer
    3. npm install
    4. npm run build OR npm run pro


    If the project helps you, buy me a cup of coffee!


    Proudly inspired by hls.js, rtsp player - for sponsoring the adaptation of jMuxer for Node.js


    npm i jmuxer

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    • samirkumardas