SVCD MP2 Audio Has To Be Stereo?

[zilog_jones]

Er, does it? I tried authoring an SVCD with mono MP2 (224kb/s I think) audio, but when played on my standalone DVD player it just made some weird high-pitched noises with no relation to the actual sound.

Does stereo-encoded MP2 actually take up more bandwidth or anything than mono at the same bitrate?

[DJRumpy]

Bitrate is what defines the amount of space an audio sample takes up. The contents are pretty much irrelevant. An audio stereo sample at 224 Kbps would take up exactly the same space as a 224 Kbps Mono sample.

Mono audio is supported by SVCD. I would suspect your audio was messed up during the conversion to MONO. Check it before you mux it back into the video stream.

I would think you could lower the bitrate for the mono sample though. SVCD supports anything from 32 Kbps to 384 Kbps. Try lowering it to 128 Kbps and see if the quality is acceptable.

[zilog_jones]

The audio track was perfectly playable on my PC, along with the muxed MPEG2. It's just my DVD player didn't seem to like it. It is a JVC XV-N55 which seems to be a bit screwy with some stuff, e.g. how it doesn't want to work with any kind of SVCD subtitles. Maybe mono MP2 is another one of those things? If it doesn't take up any less space than stereo, I don't think it's much of a problem, especially since I'm usually sourcing from stereo audio anyway.

[DVO]

If you want to use mono you can reduce the bitrate by half compered to stereo so you will save space if you do that. But if you you got trouble playing it better stick with "fake" stereo, 128k is not that much anyway...

[DJRumpy]

Subtitles on SVCD are one of those IFFY things. You can find out if your player supports them in the DVD Players section to the left. It's possible your player just doesn't like mono. Seems there are a lot of players that support SVCD, but not the full specification.

[thor300]

A mono at 224kbps would equal to a stereo at 448, and SVCD specs say maximum audio bitrate is 384kbps. That could be a problem in your case. I noticed that for example CCE will automaticly set the bitrate to half when its mono, i guess thats done to ensure compliance. CCE is probably one of the most compliant encoders available, so its probably a good reason for this. So in my theory, a 192kbps mono file should work.

[DJRumpy]

I don't think that would cause the problem. Unless he actually encoded the mono at 448Kbps, then it would still be a 224Kbps audio stream. It shouldn't matter what it would look like with more channels. The player should only see bitrate.

You could always demux the audio and verify it's bitrate.

What did you use to encode the audio?