Introduction to Enabling Videos with Multiple Audio Streams

This topic provides the basic instructions to enable assets to have multiple audio tracks (multi-audio). Typically, this is used for videos with audio tracks in different languages and/or audio tracks with additional information such as audio descriptions (for viewers with visual impairments), and audio commentary, such as from the director. The multiple audio tracks include the available codecs, channels and bitrates. The combination of these parameters define the unique audio track in the media files.

Major differences to consider with Multi-Audio

The following areas are unique to videos with multiple audio tracks:

Support Environments for Multi-Audio

Web Browsers

All browsers support multi-audio, with the following exception:
  • HLS when using only the main_html5.js plugin on Android Chrome devices (Bitmovin plugin must be used).

Supported App Environments Supporting Multi-Audio

Supported Features/Combinations for Multi-Audio

We currently support the following with Multi-Audio:
  • Multiple AAC audio streams in HLS and DASH stream packaging, Stereo Only
  • Multiple audio streams in the following packaging types:
    • HLS, eHLS
    • HLS + FairPlay DRM (h264 codec) - supported for Azure, not Elemental
    • MPEG-DASH, MPEG-DASH + Widevine/PR
    • Up to six audio tracks

Unsupported Features/Formats with Multi-Audio

We currently do not support the following with Multi-Audio

  • Multi-Audio Streams with HEVC Codec
  • Multiple bitrate renditions for the same audio track (i.e. with the same language track)
  • Multi-Audio with SSAI
  • Late Audio Binding (adding an audio track after a stream has been fully processed)
  • AC3 or e-AC3 (Dolby) Audio tracks

Also in this section: