2007/12/30, Mishehu Mashehu <[EMAIL PROTECTED]>:
> I've been using vobcopy and dvdbackup, and want to be able to extract the
> multichannel audio. I have only been able to get 2 channel audio out at any
> time.
>
> If anybody can assist and provide me with the information necessary to get
> the 5.1 channel stream out, I'd appreciate it. I must be misunderstanding
> something in the manpage.
$ man transcode
* AC3 / Multiple channels
When you do import an audio stream which has more then two
audio channels - this is usually the case for AC3 audio -
transcode will automagically downmix to two channels (stereo).
You'll see line like
[transcode] A: downmix | 5 channels -> 2 channels
This is done, because most encoders and audio filters can not
handle more than 2 channels correctly. The PCM internal repre-
sentation does not support more than two channels, audio will
be downmixed to stereo No downmix will happen, if you use AC3
as the internal audio codec or use audio pass-through.
and
OPTIONS
-A use AC3 as internal audio codec [off].
Only pass-through supported.
and
-P flag
pass-through flag (0=off|1=V|2=A|3=A+V) [0].
Pass-through for flag != 1 is broken and not a trivial thing to
fix.
In other words, you would only be able to keep 6 channels if you were
to use ac3 as the internal audio code and passed it through, but the
only pass-through that works is video-only.
Unless this area has been addressed by the recent upheavals I would
guess you need to use a different tool at present. Try mencoder?
M
