[MEncoder-users] multi-channel encoding

[Giacomo Comes]

On Sun, Aug 05, 2007 at 04:05:37AM +0200, Grozdan Nikolov wrote:
> Hi,
> 
> How does one properly encode to multi-channel audio from a DVD? Say I have a 
> DVD with 5.1 channels and I want to encode the audio to AC3 but with a lower 
> bitrate preserving all channels. Do I have to use with mencoder the -channels 
> 6 option or the -af channels=6 or both? 

Both in this way:
-channels 6 -af channels=6:6:0:0:4:1:1:2:2:3:3:4:5:5

The routing is necessary because mencoder (still) does not take in account the channel order
of the specific codec.
This channels routing is valid only if encoding from ac3 to ac3. If you do aac -> ac3 or dts -> ac3
the routing is different.

Ciao
Giacomo