Mono Ogg File?

[kagoru]

Is it possible to encode an 2 channel ac3 (which actually is mono) to mono-ogg but make it play back on left and right speakers? That would save A LOT of bitrate or double the quality.

TIA.

[MaTTeR]

I think I tried this last week with HeadAC3he and it didn't work. I recall D A mentioning a bug in John33's Vorbis dll that had something to do with mono encoding. I might be wrong so perhaps D A can clarify.

Have you tried this in OggMachine? I'm unable to test it as I'm traveling with my laptop ATM.

EDIT- If you already have the mono encoded Ogg why not turn off the center channel speaker or select stereo mode on your amp? I do that with the DD 1/0 Chinese martial art flicks. Who wanted to listen to an entire movie out of the center channel? Yuck:D

[DarkAvenger]

Hmm, no this is not a bug in vorbis.dll, it is a bug in HeadAC3he, as you cannot select just the center channel for output, which is necessary for mono encoding. Didn't think of this possibility. :rolleyes: Going to fix it...

[canadian_fbi]

as far as i know, the oggds filters still have playback issues when it comes to mono vorbis files. i used oggenc to encode a wav that i'd downmixed to mono, so it's not exactly the same thing, but if anyone successfully plays back a mono encoded ogg stream in a movie, i'd like to know.

(link to previous thread i posted about this)
http://forum.doom9.org/showthread.php?s=&threadid=19641

[LigH]

Vorbis encodes audio not per left and right channel, but per direction and distance. Because the direction is always constant, Vorbis will compress the directional component very well, and most of the bitrate is spent for the distance component. You may even ensure this by chosing "medium / heavy lossy" mode for location encoding (and enable "hold"). Of course, you shall perform a listening test in case of any doubt.

[DarkAvenger]

@Ligh

You don't have to check hold. It has just GUI importance. Find out its use... I thought some might find it useful. :)

[LigH]

I know - it prevents that the setting which is held changes automatically when the quality changes. So if you first set the loss mode and then change the quality, it's better to lock the loss mode.

[DarkAvenger]

Ok, you got it. ;)

[kagoru]

Thanks for you answers! But how do I actually encode a 2 channel AC3 (LEFT and RIGHT channel are the same) with headac3he or oggmachine? Do I just select one channel for input (e.g. LEFT) instead of both? And Do I just select ONE channel for output? The problem is that I want to encode the ac3 as mono-ogg (to save space) but still be able to play it back on both speakers. How would I do that?

TIA.

[kagoru]

Have you added support for mono-ogg files in headac3he yet? I can't wait to get my mono audio ;-).

TIA.

[DarkAvenger]

Not really, but if you send me an email, I can sent you a "hacked" version.