[mythtv-users] Capturing 5.1 audio

[Michael T. Dean]

On 11/12/05 17:15, Nathan Allen Stratton wrote:

>My current myth box uses 2 convertx boxes, but I just bought a HD-3000
>card and monday should have my antenna. Do I need to do anything special
>to get 5.1 channel sound?
>
Nope.  ATSC (US high-definition TV) is broadcast already encoded using 
the MPEG-2 system.  The audio is encoded in an AC-3 stream within the 
transport stream.  So, it's just there.

> How is 5.1 compressed with mp3?
>  
>
MPEG-{1,2} Layer {2,3} audio only supports 1- or 2-channel audio.  There 
is a "stereo compatible" version called "MP3 Surround" which supports 
5.1 channel audio in much the same way that Dolby Surround provides a 
"stereo compatible" 4.0 channel audio encoding.  However, ATSC requires 
the use of AC-3 for audio content (although they call it A/52), so no 
extra work is required to get it.

Mike