• Compression Techniques

  Problems Encoding 5.1 AAC Quicktime

  Posted by Matthew Keane on November 6, 2005 at 1:39 pm

  Hello,

  I seem to have hit a problem encoding a h.264 Quicktime with 5.1 AAC audio. The video is fine, but I seem to end up with missing, or empty, audio tracks in the resulting quicktime. The audio files are 6 individual WAV files supplied by the recording studio.

  First attempts were exported via compressor from Final Cut Pro with the AIFF audio tracks layed out on 6 audio tracks. The audio amp connected via the optical out on the G5 showed only two tracks, which was confirmed when I soloed each track in Quicktime. Although the file info shows 6 tracks, only the first two tracks contained audio, the other four tracks were empty.

  Since I also want to output a WMV with 5.1 audio using Flip4Mac, I followed the instructions on their site and prepared a Soundtrack Pro project with the 6 audio tracks and assigned them to the appropriate channels in the compressor export option. I set it crunching and the result was again a Quicktime with AAC audio containing 2 good channels and 4 empty channels. The WMV export showed only 2 channels in the file info in the player.

  If I take the same audio files and export to an ac3 file, either in Compressor, or using the Soundtrack Pro project, I get a 5.1 audio file just as I want, and all the tracks are recognized by the audio amp. So, any ideas where I’m going wrong with the AAC output? Have I forgotten to check a hidden ‘make it work, dammit’ option?

  Thanks,
  Matthew

  Matthew Keane replied 19 years, 1 month ago 1 Member · 0 Replies
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