Divx to SVCD conversion - audio problems

[Wills]

I have a divx movie that I'm trying to rip into SVCD. I usually rip the audio to a 44 Khz wav file using vdub, and then use that and the divx file as the sources to create my SVCD mpg using TMPGEnc.

Problem is, although the audio is fine on the divx, when I convert it to .wav, the finished file comes through with a little problem - upper frequency resonance - the film is very quiet anyway, and it's not a big deal but when I play it on my hifi it really becomes apparent and quite annoying.

It's difficult to describe - it happens mostly when there's dialogue - it's as if the voices are resonating in a really small, metallic high pitched room - everything's still very audible, it just really grates on the nerves after a while.

I tried leaving it at 48 Khz and making a non-standard SVCD, which my stand-alone player is fine with, but this didn't solve the problem.

Are there any settings in VDub to counteract this, or any other solutions, for that matter?

Many thanks.


Wills

[mats.hogberg]

Extract the audio using direct stream copy / Save WAV. (Use File Info in VDub to see what type of encoding is used (AC3, MP3, OGG...)
This will give you the audio in the format it was before interleaved with video. It will end in .wav, but rename according to VDubs info (=.AC3 or .MP3 or...) Decode to WAV using a dedicated ???toWAV decoder.

/Mats

[Wills]

cheers mats.

Do I need to convert it to a .wav before making my SVCD?
Or can I use the file as it is ? (having direct streamed copied it to a file)

And if I have to use a ???toWAV decoder, can you recommend one?
I have SoundForge 6 but maybe it needs a plugin to deal with the more esoteric formats?

Many thanks

w

[mats.hogberg]

You probably have to go via a .wav before using it in TPMGEnc, yes. Even if it seems like I've persuaded TPMGEnc to accept an AC3 as audio input, you're to the mercy of TMPGEncs ac3 to mp2 conversion when it comes to audio quality. I always prefer to find the best tool for a specific task - TPMGEnc is great at creating mpegs from various video formats, but it's not an audio conversion tool.
For MP3, I tend to use CDEX to decode to wav. AC3 is decoded with Headac3he.
Of course, you could try SoundForge and see if it can open you direct stream copy of the audio track. (But SoundForge, just like PhotoShop that someone compared SF to in another thread, is such a behemoth that 99.997% of the time, you just need 0.003% of what it can do - A waste of computing power and resources!)
Some seem to use GoldWave to get the audio track from "any" AVI by just opening the AVI and saving WAV.

/Mats

[Wills]

Cool.

Last thing - sometimes I do my standard .wav conversion, and because it isn't interleaved (I think?), the audio is perfect (well good enough for me....)

How can I tell if it's interleaved or not? (so I can tell if it's going to have that resonance problem or not..)

For instance, the one I'm trying now has audio that uses the Fraunhofer IIS MPEG Layer-3 Codec.

Would that automatically be interleaved because of its format?
Is there a guide that would tell me which codec is interleaved and which isn't?

Thanks for all your help.

wills

[mats.hogberg]

The interleaving (as in Audio Video Interleaved) is that the audio file (an MP3 for instance) and the video file (a DivX) are interleaved with eachother - Like, first comes a chunk of the video file, then a piece of the audio file, then a piece of the video file again, then... and so on - If I've got it right.
No "one media" file is interleaved. If it's only video, or only audio (MP3, wav...) it's not interleaved.

/Mats

[Wills]

ahh, gotcha. That's pretty basic stuff. I should know that already!

So there's no real way of knowing whether or not it will sound ok if I just do my simply rip to wav and then SVCD encode....?

cheers
wills

[mats.hogberg]

No, not if you really want to hear how it will sound before you create the SVCD. Ideally, you'd even encode it to mp2 to really be sure, then let TMPGEnc encode video only, and multiplex your "hand made" mp2 with TMPGEncs m2v, but a reasonable compromise is to create a nice wav at the right sample fq (44.1 kHz (or 48 kHz if your player takes XSVCD)) before letting TMPGEnc encode it.

/Mats

[Wills]

gotcha

right, am off for several hours of playing around with software.

I wouldn't even have to do this if my wretched graphics card didn't 'frame stutter' when it plays some divx / xvid movies on the TV-out.

Some are fine, but some, for no reason that I can ascertain, make camera motion really non-fluid and jerky. And unwatchable.....

anyway, thanks v much for all your wise words, much appreciated.

wills