How do you make 5.1 ogg?

[sumpm1]

How do you make them, and where can I find info about them?
Couldnt find any at xiph.org

[Doom9]

well.. you're on doom9's forum... how about checking doom9's guides? (http://www.doom9.org/guides.htm)

[DSPguru]

you can make them with OggMachine, for instance, but afaik, you can only play them with powerdivx 4, which isn't public yet.

anyway, 5.1ogg isn't a good idea currently.
imho - you should use either 5.1ac3 or 2ch ogg vorbis.

[sumpm1]

Sorry Doom, when I read those guides for ogg, I thought that they were only for 2 ch ogg, thanks


@DspGuru

I was always under the assumption that a stereo file did not have 2 distinct left and right channels, giving you 2 true mono chanels. I mixed 2 songs together, one on the left channel and the other on the right and encoded to mp3. When I listened to it, I adjusted the balance to the left and right and both of the channels were distinct, and you could only here one song when totally faded left or right. So it seems that there are 2 distinct channels, are there?

I also know that there have been karaoke filters that will remove the vocals on a stereo track by removing the center channel, since vocals were usually exactly the same on both channels(vocals are mono, appearing on both channels). So this kind of gives you a third channel for 2 channels. By using a filter like that, is it possible to get 6 channels out of 2?

[DJ Bobo]

I think, it's senseless to make 5.1 ogg
Keeping the AC3 is the best choice if one needs 5.1 sound, because AC3 is already high compressed, so you will only cause worse quality when transcoding to ogg.

[ChristianHJW]

Originally posted by bobotns I think, it's senseless to make 5.1 ogg .. this is certainly true for the time being ... but things may change pretty quickly if

- all producers of AC3 decoding filters ( WinDVD, PowerDVD, etc. ) keep on scerwing their filters for us, such that they cant be used from other applications ... this will lead us to a situation one day where we cant use the old filters on the newest OS ... and we maybe wont be able to play our movies with AC3 sound anymore :(

- Vorbis developers implement channel coupling and/or different quality settings for different channels ( sub/rear ) .. resulting in 160 - 200 kbps for a nice 5.1 Vorbis stream

Think about that ;) ...

[MaTTeR]

@bobotns

Have you did Vorbis 5.1 listening tests and compared? If so, what q level did you use?