Dolby Digital

I have the latest 2.3.1 Software on my apple TV (ATV) along with the latest ATV files 3.5.1. When I play my avo film files my Sound Processor tells me that the input from the ATV is PCM not DD 5.1. I have downloaded a DD 5.1 WAV file and put that on the ATV when I play that my Sound Processor recognizes the input as DD 5.1. I don’t really understand why my AVI files are only being recognized as PCM stereo. I searched around and checked that AC3 passthrough is set to YES. Is there anything else any of you guys can suggest or do you have the same problem. Maybe it’s the way the files were encoded, i’m not sure. Any advice would be well appreciated.

According to the ATVFlash support team Apple restricts ATv to needing 2 separate sound tracks to be recorded with the file for Dolby Digital to work. 1st track to be AAC, 2nd to be AC3 passthrough. Handbrake offers this when converting video files although I not not yet tried to create AVi files.

This is what he is talking about: