Bit of help with audio sync / virtualdub?

[Lester Burnham]

I've been noticing some audio sync problems with some DVDs I've converted to AVI / DivX. These are my own, legally owned, retail DVDs, that I convert to play on a personal media / video player (Archos AV440).

Probably the majority of my DVDs are region 2, being in the UK, but a fair percentage are R1 / US releases. And with a rough guess, it's the conversions from R1 DVDs that seem to show some audio sync issues, a fair way into the film.

I extract one VOB from the DVD (just the film with the main audio track), using DVDDecrypter. I then convert using virtualdub (the mpeg2 variant), using the DivX codec for video (I tend to use 1384kbps for video bitrate, standard profile). I use Lame MP3 encoded audio (CBR at 160kbps), all within virtualdub.

I've only noticed the audio sync issue with some conversions, but from memory, they seem to be from R1 DVDs.

My Archos AV440 is running the latest firmware (2.0.34) which supposedly addresses audio sync issues (however, this was mainly to do with VBR audio).

What I was wondering is whether my conversion procedures are not quite valid for R1 / NTSC DVDs as input - should I be doing something different WRT to the frame rate?

Also, is it valid to use virtualdub that way, I've read a few comments regarding colour space conversion from YV12 to RGB back to YV12 again?

And lastly, is there any obvious benefits of DivX codec over Xvid where these sorts of conversions are concerned?

Many thanks in advance for any help.

[Baldrick]

Why not try autogk or fairuse wizard? They are "optimized" for ripping and converting to divx or xvid.

or learn how to use dgindex(the best dvd decoder, perfect for r1 dvds that can be a bit tricky to convert) and frameserve to virtualdubmod or virtualdub-mpeg2.

[Lester Burnham]

Why not try autogk or fairuse wizard? They are "optimized" for ripping and converting to divx or xvid.

or learn how to use dgindex(the best dvd decoder, perfect for r1 dvds that can be a bit tricky to convert) and frameserve to virtualdubmod or virtualdub-mpeg2.

Well it's a fair point to suggest other tools - but indeed there's any number, including PocketDivXEncoder, and a number of others.

I guess my leanings towards virtualdub, being that numerous of these all-in-ones tend to front it, as does the Archos supplied conversion utility.

I think really, I've been happy with the results - in general - with virtualdub, and I liked the ability to be slightly more involved, I guess I just saw it as a learning thing as to what I'm not doing quite right for the conversions I've done that have audio-sync issues. I was trying to understand what's wrong, or what needs to be done differently, that's all.

[Lester Burnham]

I've done some further investigation into this - I've currently got around 20 movies on my AV440, out of those, 6 are region 1 / NTSC conversions, the rest are all region 2 / PAL conversions.

None of the region 2 / PAL conversions show any audio sync issues (I check this, by zipping forward a little over an hour into the movie, and looking at the audio sync).

5 out of the 6 region 1 / NTSC conversions show audio sync issues, but curiously one doesn't (Fight Club), and one shows only slight issues, whereas all the rest that have issues, the audio is quite out of sync (at a guess, a good number of seconds, and the audio is ahead of the video). I'm not sure why, because I'm pretty sure I've used exactly the same procedure to convert all the films.

What I don't get is that the procedure I'm following doesn't seem to favour PAL (or the PAL frame rate) - as I'm pretty sure the default (which I've currently not toyed with) is to use the source frame rate, so I'm a little puzzled, really.

What I was wondering, is whether I should be setting the frame rate as per the source, or setting it to one absolute value, or leaving it to default.

The audio I'm encoding using Lame MP3 ACM, 48khz 160kbps stereo. I chose 48khz, as I understand it's what the audio source on the DVD should be.

[barrybear]

I have had problems using lame as my audio compresser. Try using A diferant pm3 compresser

Barrybear