Transcode Support and Passthrough Support for Dolby Audio Codecs - AWS Elemental Live

This is version 2.18 of the AWS Elemental Live documentation. This is the latest version. For prior versions, see the Previous Versions section of AWS Elemental Live and AWS Elemental Statmux Documentation.

Transcode Support and Passthrough Support for Dolby Audio Codecs

Three Dolby codecs are supported and can be transcoded or passed through as follows:

  • Dolby Digital (AC-3): Can be re-encoded as Dolby Digital or the original Dolby Digital can be passed through.

  • Dolby Digital Plus (E-AC-3): Can be re-encoded as Dolby Digital Plus or the original Dolby Digital Plus can be passed through.

  • Dolby E: Can be passed through as Dolby E. Cannot be re-encoded as Dolby E.

The following table specifies the fields on the input side and on the output side that control passthrough versus transcoding.

Input Output > Stream
Codec Detected in Input Value in Unwrap SMPTE 337 Field Value in Output Codec Field Value in Automatic Passthrough Field Result
Dolby Digital n/a Dolby Digital n/a Re-encoded to Dolby Digital
Dolby Digital n/a Dolby Digital Passthrough n/a Passthrough of Dolby Digital
Dolby Digital Plus n/a Dolby Digital Plus Checked Passthrough of Dolby Digital Plus
Dolby Digital Plus n/a Dolby Digital Plus Unchecked Re-encoded to Dolby Digital Plus
Dolby Digital Plus n/a Dolby Digital Passthrough n/a Passthrough of Dolby Digital Plus
Dolby Digital Plus and a non-Dolby Digital Plus codec n/a Dolby Digital Plus Checked The non-Dolby Digital Plus audio is transcoded to Dolby Digital Plus. The Dolby Digital Plus audio is passed through (it will not be re-encoded as Dolby Digital Plus).
Dolby Digital Plus and a non-Dolby Digital Plus codec n/a Dolby Digital Plus Unchecked The non-Dolby Digital Plus audio is transcoded to Dolby Digital Plus. The Dolby Digital Plus audio is re-encoded to Dolby Digital Plus.
Dolby Digital Plus and a non-Dolby Digital Plus codec n/a Dolby Digital Passthrough n/a Not valid: setting up like this causes a validation error.
Dolby E in a PCM stream tagged with SMPTE 337 Unchecked Uncompressed WAV n/a Passthrough of Dolby E.
Dolby E in a PCM stream tagged with SMPTE 337 Unchecked Uncompressed AIFF n/a Passthrough of Dolby E.