If your Apple TV is connected to a Dolby Digital-capable sound system, your content can have true surround sound.
Apple TV will pass through 5.1 surround sound audio encoded in Dolby Digital AC-3. The AC-3 audio must be properly included in the movie in order for it to pass through correctly.
To create content for use with Apple TV, the movie must have two audio tracks:
Note: Both tracks should have the same sample rate (48 kHz is normal).
For compatability, the following is required:
Apple TV uses the AC-3 track as a pass-through mode only. For example, it passes data out to an A/V receiver capable of Dolby Digital playback. The AC-3 audio is sent over the HDMI and the optical audio output of Apple TV.
To select AC-3 data through these ports, go to Settings > Audio > Dolby Digital Out and select On.
These movies can be created using applications such as FinalCut Express and FinalCut Pro.
Note: The AAC track is used in any situation where just stereo output is required.
Important: Information about products not manufactured by Apple is provided for information purposes only and does not constitute Apple's recommendation or endorsement. Please contact the vendor for additional information.