[MPlayer-users] Again on 5.1 vorbis encoding

[Alessio Sangalli]

I've read the relevant topics on the mailing list archives, and I think 
the conclusion is that there are problems to playback a ogg file with 
vorbis 5.1 audio if you use an external digital amplifier.

That's because you have a vorbis 5.1 stream and the amplifier only 
understands ac3 audio. Mplayer can't (yet!?) convert realtime from 
vorbis to ac3.

However, if the sound card already have the 5.1 outputs directly driven 
(as many nowadays do, I have such an audio device integrated on the 
motherboard) there should be no problems. Even in the cased you only 
have stero speakers Mplayer should be able to downmix the 5.1 vorbis 
audio (am I correct?).

Now what I ask is: understanding all the problems and limits of this 
approach, how can I extract the 5.1 audio from a DVD title and encode it 
into a vorbis file?

Will I be able to merge multiple audio streams in an OGM file? (for 
example, english and german audio tracks) What if I merge 5.1 AND stereo 
streams all together? (sometimes the english sound track is 5.1 and the 
italian one is only stereo)


thank you and bye bye
as