Action: Encode

Encode your video to a specified format using built-in ffmpeg utility. You don't need to have ffmpeg installed on your system.

Installation

If you are using binary version of the nexrender, there is no need to install the module, it is included in the binary build.

npm i @nexrender/action-encode -g

The module downloads a statically defined version of ffmpeg and places it into /temp/nexrender folder (by default). If you have ffmpeg installed on your system already, you can provide an env variable to use it:

$ NEXRENDER_FFMPEG=/usr/bin/ffmpeg nexrender-cli ...

Usage

When creating your render job provide this module as one of the postrender actions:

// job.json
{
    "actions": {
        "postrender": [
            {
                "module": "@nexrender/action-encode",
                "output": "foobar.mp4",
                "preset": "mp4",
                "params": {"-vcodec": "libx264", "-r": 25}
            }
        ]
    }
}

Information

• output is a path on your system where result will be saved to, can be either relative or absulte path.
• input optional argument, path of the file you want to encode, can be either relative or absulte path. Defaults to current job output video file.
• preset optional argument, if provided will be used as a preset for the renderer, if not, will take input directly from params
• params optional argument, object containing additional params that will be provided to the ffmpeg binary

Params (optional)

Params are passed as an object of key-value pairs. In case of a param without value, you can provide null or empty string "" as a value. Eg. {"-vcodec": "libx264", "-r": 25, "-an": null} would end up as -vcodec libx264 -r 25 -an in the final ffmpeg command.

// job.json
{
    "actions": {
        "postrender": [
            {
                "module": "@nexrender/action-encode",
                "output": "foobar.mp4",
                "preset": "mp4",
                "params": {
                    "-vcodec": "libx264", 
                    "-r": 25,
                    "-an": null, // disable audio
                }
            }
        ]
    }
}

Presets

There are a couple of default presets included with the build. You can provide params field to override any of the values there.

mp4

{
    '-acodec': 'aac',
    '-ab': '128k',
    '-ar': '44100',
    '-vcodec': 'libx264',
    '-r': '25',
}

ogg

{
    '-acodec': 'libvorbis',
    '-ab': '128k',
    '-ar': '44100',
    '-vcodec': 'libtheora',
    '-r': '25',
}

webm

{
    '-acodec': 'libvorbis',
    '-ab': '128k',
    '-ar': '44100',
    '-vcodec': 'libvpx',
    '-b': '614400',
    '-aspect': '16:9',
}

mp3

{
    '-acodec': 'libmp3lame',
    '-ab': '128k',
    '-ar': '44100',

}

m4a

{
    '-acodec': 'aac',
    '-ab': '64k',
    '-ar': '44100',
    '-strict': '-2',
}

gif

{
    '-i': input,
    "-ss": '61.0',
    "-t": '2.5',
    "-filter_complex": `[0:v] fps=12,scale=480:-1,split [a][b];[a] palettegen [p];[b][p] paletteuse`,
}