Fork of https://github.com/nodef/extra-ffmpeg extra-ffmpeg library, with removed install.js procedure (assumes you already have ffmpeg binaries installed on system)
Decode, encode, transcode, mux, demux, stream, filter, and play media through machine (via "ffmpeg").
const ffmpeg = require('extra-ffmpeg');
// ffmpeg.sync(<options>): stdout when done
// ffmpeg(<options>)
// -> Promise {stdout, stderr} when done
// <options>: [{ // see ffmpeg -h
// outfile|o: // name of output file
// }]
ffmpeg.sync([{y: true}, {i: 'concat:0.mp3|1.mp3'}, {acodec: 'copy', o: 'aud.mp3'}]);
// concat 0.mp3, 1.mp3 to aud.mp3
ffmpeg.sync([
{y: true, err_detect: 'explode'}, {loop: 1, framerate: 1}, {i: 'img.jpg'}, {i: 'aud.mp3'},
{vcodec: 'libx264', crf: 0, preset: 'veryfast', tune: 'stillimage',
vf: 'scale=trunc(iw/2)*2:trunc(ih/2)*2', acodec: 'copy', shortest: true, o: 'vid.mp4'}
]);
// get video vid.mp4 from still image img.jpg and audio aud.mp4