Home » API Reference » Encoding Settings » Format And Codecs » Audio Codec


:String permalink

API Versions: V1, V2

Parent: outputs

Default: Determined by the format, profile, or video_codec. aac if none are provided.

Valid Values: aac, ac3, amr, eac3, mp3, pcm, vorbis, and wma

Compatible Job Types: All

Example: mp3


The audio codec to use. The default codec depends on the video codec and format selected.

Note that MP3 audio in a MP4 container is valid alongside H.264 video content, but does not play back in Quicktime.


  • aac is compatible with h264 video (mp4, m4f, 3gp, or flv format), mpeg4 video (mp4 or 3gp format), and vp6 (flv format)
  • vorbis is compatible vp8 video (webm format) and theora video (ogg format)
  • wma is compatible with wmv video and the wmv format
  • mp3 is compatible with h264 video (mp4, 3gp, or flv format) and wmv video (wmv format). mp3, h264, and mp4 will not play back in Quicktime
  • pcm is compatible with h264 video and the mxf format.
  "input": "s3://zencodertesting/test.mov",
  "outputs": [
      "audio_codec": "mp3"
  <outputs type="array">