ffmpeg-decode-audio-buffer.js

var execFile = require('child_process').execFile
module.exports = function (context, path, start, duration, cb) {
  var child = execFile('ffmpeg', [
    '-i', path,
    '-ss', start,
    '-t', duration,
    '-f', 'wav',
    '-acodec', 'pcm_s32le',
    'pipe:1'
  ], { encoding: 'buffer', maxBuffer: 10 * 1024 * 1024 }, function (err, result, stderr) {
    if (err) return cb(err)
    context.decodeAudioData(new Uint8Array(result).buffer, function (result) {
      cb(null, result)
    }, function (err) {
      cb(err || new Error('Decode error'))
    })
  })
  child.stdin.end()
}