Compressor 4 - About Dolby Digital Professional Source Media Files

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About Dolby Digital Professional Source Media Files

You can use Dolby Digital Professional AC-3 audio files as source media files for your jobs.
There are two common reasons to want to do this.

To test a file you just encoded: Since you cannot preview the Dolby Digital Professional

output settings, importing an encoded file into a job allows you to play it and verify
the settings.

To convert a Dolby Digital audio file to another format: Since not all media players include

Dolby Digital decoders, you may find that you need to transcode the file into another

Compressor includes a Dolby Digital decoder that it uses whenever you play or transcode
Dolby Digital audio files. This makes it possible to verify the Dolby Digital Professional
output settings of a previously encoded file on your system without requiring you to
have an external Dolby Digital decoder. To hear surround sound you must have an external
surround sound device connected to your computer’s USB or FireWire output. The audio
is mixed down to two channels if you play the audio using your system’s stereo speakers.


Since the audio output is already decoded and not in the Dolby Digital format,

the optical output cannot be used when playing Dolby Digital files from Compressor.

Tip: Add an .ac3 extension to the filename if Compressor does not allow you to add it to
a job.