@augmentality/node-omx

node-omx

A Node.JS video player for the Raspberry Pi (and other devices using Broadcom's OpenMax-based Multi-Media Abstraction Layer API)

This is a compiled module for NodeJS which provides hardware-accelerated video and audio playback on the Pi. Everything is built-in, it doesn't shell out to other applications.

Prerequisites

Please check npm -v to make sure you have npm@6.8.0 or higher. The version of npm included with Raspbian is, of course, hopelessly out of date and can't compile this module.

For raspbian:

apt-get install build-essential cmake libavutil-dev libavcodec-dev libswresample-dev libavformat-dev

Install

npm install --save @augmentality/node-omx

Features

• Asynchronous loading, playback and control
• Instant start (once loaded)
• Network or local playback
• Seamless looping with a/v sync
• Pause / Resume
• Get playback time
• Callbacks for play state
• Seamless switching between videos with multiple instances
• Supports mp4, mkv, mov, or any container supported by ffmpeg

Supported Platforms

Any device supporting Broadcom's OpenMax-based Multi-Media Abstraction Layer API.

For convenience, on unsupported platforms, the module will still build and will output placeholder messages instead of playing media.

Usage Example

Javascript

const omx = require('@augmentality/node-omx');
const readline = require('readline');

readline.emitKeypressEvents(process.stdin);

let state = 0;
async function run()
{
    const n = new omx.Player();


    n.onPlaybackState.subscribe((pState) =>
    {
        state = pState;
        switch(state)
        {
            case 0:
                console.log('Stopped');
                break;
            case 1:
                console.log('File loaded');
                break;
            case 2:
                console.log('Playing');
                break;
            case 3:
                console.log('Paused');
                break;
        }
    });

    await n.open('http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_30fps_normal.mp4');
    n.play();
    n.setLoop(true); // Enable seamless looping

    setInterval(() =>
    {
        if (state > 0)
        {
            console.log('Playback position: ' + n.getTime());
        }
    }, 1000);

    let speed = 1.0;
    let paused = false;
    process.stdin.setRawMode(true);
    process.stdin.on('keypress', (str, key) =>
    {
        if (key.ctrl && key.name === 'q')
        {
            process.exit();
        }
        else
        {
            switch(key.name)
            {
                case 'up':
                    speed += 0.01;
                    console.log('Playback speed: ' + speed);
                    n.setSpeed(speed);
                    break;
                case 'down':
                    speed -= 0.01;
                    console.log('Playback speed: ' + speed);
                    n.setSpeed(speed);
                    break;
                case 'space':
                    if (!paused)
                    {
                        n.pause();
                        paused = true;
                    }
                    else
                    {
                        n.play();
                        paused = false;
                    }
                    break;
            }
        }
    });
}
run().then({});

Caveats

• A read-ahead buffer is implemented to help smooth playback. If you disable looping, the reader may have already looped, in which case playback will end at the end of the next run.
• Only H264 video is supported at present.
• Looping is not possible when playing h264 annex-b (raw H264). Mux into a container if you need this.