Dolby AC3 Decoder

If you're working on a PPC Mac and have an older version of DVD-SP, you can install A.Pack from the DVD-SP install disc. It will convert AC3 audio. Compressor may be able to as well, but I've never tried it.

-DH

About Importing Audio Files

Final Cut Pro allows you to import audio files from other music and sound editing applications, as well as audio from audio CDs. When you import audio files into Final Cut Pro, you need to make sure that their settings match your sequence settings. If your audio clips’ settings don’t match the
sequence settings, you can still edit with them, but Final Cut Pro does real-time conversion which reduces overall playback performance. This chapter discusses the types of audio file formats you can import, as well as methods for converting audio files so they match your sequence settings.
For more information about digital audio, see Volume III, Chapter 3, “Audio Fundamentals.”

What Kinds of Audio File Formats Can Be Imported?

Final Cut Pro allows you to directly import any audio format compatible with QuickTime. However, *only uncompressed file formats* such as AIFF and WAVE files can be used for editing. Final Cut Pro supports AIFF, WAVE, Sound Designer II, and single- track or multitrack QuickTime movies. Natively, Final Cut Pro captures to QuickTime movie files with one or more audio tracks.

+Source: Final Cut Pro users Manual+

Dolby AC3 is a compressed format.

Have you tried mpeg streamclip? It will convert the audio from an mpeg file which is encoded as ac3 to an aiff, so it might do it to an ac3 file. If you don't have mpeg streamclip go to versiontracker.com and do a search for it.

Good call, Michael. I just tried that and it works.

To the OP: Open the AC3 file in MPEG Streamclip, then go to File->Export Audio. Set the file type to AIFF and the sampling rate to 48khz and export. You can use the resulting file in FCP.

-DH

What is the source of your ac3 material?
Can your Motu real-time convert that signal and send AIFF into FCP?

I know of no way to capture an AC3 stream. Not saying that there isn't a way ... just none that I know of.

-DH

and frankly, why would you WANT to capture as AC3, since by definition it is a lossy codec. Throws away audio data it thinks your ears won't miss. Not a great way to start. It's tempting as well to think of AC3 as a way to transport lots of audio data in a small package, but encoding, then decoding, then re-encoding is never a good idea, as is the case with any lossy medium.

Reid C