Audio/Video Sync problems (DivX avi -> VCD)

[boylemeister]

Hi,
Total newbie here - I've tried to burn a VCD of a DivX avi file I downloaded. I split the file using Virtual Dub into two avi files and created the VCD using Nero but the sound drifts out of sync as the film goes on.

Is there anything obvious I'm doing wrong or should be doing? Virtual Dub does state that 'an improper VBR audio recording in the source avi was detected' but it states that it was going to rewrite and may incorporate 0ms of skew. It also suggested decompressing to wav to fix the problem - is this required or is there another way of keeping the audio & video stream in sync?

Cheers
Stevie

[mh2360]

Download and install the Nemo codec pack from the tools section.... Check the the frame rate of the Divx 23.976 = NTSC film template, 25 = PAL , 29.975 = NTSC... Convert using Tmpgenc.

[boylemeister]

cheers for this mh, does anyone have an alternative location for the nimo codec pack? the current link just shows a exceeded bandwidth error page.

Cheers again,
Stevie

[KingJohn]

Vdub gives you this warning, incase you are going to re-encode the AVI to another AVI. Since you are not going to do this, you can ignore the error and save out the audio converted.

Audio > full processing mode
Audio > Conversion > 44.1Khz
SAVE WAV

Now use TMPGENc
Browse AVI
Browse WAV

Load VCD Template, START

Oh and Nimo can also be downloaded from http://perso.wanadoo.fr/nimo/ (If you need it)

Oh, and it might be better to use the FULL AVI dont split it, then you can use split/merge with TMPGENc after it has made the mpeg1

[Temil]

about the best way to convert from Avi over into SVCD, the best I found is listed below...

------INFO TRANSFERED FROM ANOTHER POST-----

First off, dont get upset or confused. It's really easy to do all this, just takes a little time. Now, head over to the following url and read everything all the way. Dont do anything just yet, just read it so you understand it. Only ready on this page from
"Now start Virtualdub. ..... " which is on top and
"Save the wav by clicking on Save WAV..... " which is about half way.

http://www.vcdhelp.com/virtualdubaudio.htm

Done reading it allready? .... GOOD!
Now, head over to another url listed below and read from
"Guide" which is near the top and
"Now you are ready...." which is near the midway to bottom.

http://www.vcdhelp.com/tmpgencsvcd.htm

Damn your fast! .. Ok, now just follow all those steps, and everything will work out. Trust me! .. I recommend you clip the movies top and bottom black sections, because the final MPG will add them automaticly, and make sure you pick the option "Full Screen (Keep Aspect Ration)" ..
That should do it for ya. If ya have any more problems, just let me know!
I'll keep an eye on this post for ya! =)

}Temil{

------END-----

Now, for the links to download Nimo, here is a list of those from another post I posted as well. I have been kind of busy! =)

-----INFO TRASNFERED FROM ANOTHER POST-----

some of these might not be 100% updated version, but it should work for ya.

http://www.network-error.com/divxyz/download.php3?op=mydown&did=9
http://multimedia-freaks.de/dl/check_dl.php?id=60
http://psych.freeshell.org/nimo/Nimo50Build7.exe
http://download.zdnet.co.kr/down2.asp?num=13210
http://download.zdnet.co.kr/down1.asp?num=13210
http://download.zdnet.co.kr/down3.asp?num=13210

Well, I think that should help, I will watch over the post, so just repost for any more help!

}Temil{

------END-----

Hope this info helps.

}Temil{

[Raen]

I recommend you clip the movies top and bottom black sections, because the final MPG will add them automaticly, and make sure you pick the option

Umm
Someone wanna explain to another newbie how to do that? I imagine that will cutdown the file size some..

[KingJohn]

I don't see the point in clipping out black borders, they compressed very well anyway, and hardly make a difference to the size. Since you wish to preserve the aspect ratio and could end up with the black borders again, there is little achieved by removing them, unless some logo is in them.

But to answer your question, to remove black borders, you would need to be in Full processing mode, and would need to re-encode the movie all over again. Using a filter.. Video > Filter > Add >Nul transform > cropping

The correct way to use an AVI with a improper VBR is

Audio > full processing mode
Audio > Conversion > 44.1Khz
SAVE WAV

This way the Video does NOT need re-processing

[Daagar]

You _always_ want to remove black borders if they are present in the source. That line dividing the movie and the border is very difficult for encoders, so they end up using a lot of bitrate in that area that could be better used elsewhere. By clipping out the borders completely, the encoder doesn't try to process that dividing line anymore. You will get better quality and possible smaller filesize by clipping out source borders first.

[KingJohn]

[boylemeister]

Cheers for all the help so far guys - I'll take a day to try some of the stuff out and I'll let you know how I get on.

Thanks again,

SB

[boylemeister]

Just wanted to say a big thanks to everyone who posted above - the advice helped me no end and I'm now creating perfect vcd's with vid & aud in sync.

Thanks again,

Stevie.

You _always_ want to remove black borders if they are present in the source. That line dividing the movie and the border is very difficult for encoders, so they end up using a lot of bitrate in that area that could be better used elsewhere. By clipping out the borders completely, the encoder doesn't try to process that dividing line anymore. You will get better quality and possible smaller filesize by clipping out source borders first.

These borders, they would be the ones at the top and bottom of the movie?
This might help me if this is correct. I have noticed in the movie I have
that on the bottom border there is some "Noise"? They look like rectangular
boxes moving across from one side to the other right along the edge.

[Nicholas S. Folsom]

I don't see the point in clipping out black borders, they compressed very well anyway, and hardly make a difference to the size. Since you wish to preserve the aspect ratio and could end up with the black borders again, there is little achieved by removing them, unless some logo is in them.

But to answer your question, to remove black borders, you would need to be in Full processing mode, and would need to re-encode the movie all over again. Using a filter.. Video > Filter > Add >Nul transform > cropping

The correct way to use an AVI with a improper VBR is

Audio > full processing mode
Audio > Conversion > 44.1Khz
SAVE WAV

This way the Video does NOT need re-processing

So, what should be done after we've done the cropping and the original AVI is on the left, and the WAV has been saved?

Nickers

[KingJohn]

Well the problem with the AVI you have is improper VBR, (Variable bit rate) When you get these type of AVI's you Cannot split them at this stage. If you do, you will end up with lip sync.

You could save out the whole movie uncompressed (Both Video and audio) to cure this problem, then you can split the uncompressed AVI Most people don't do this, it takes time

If the audio is uncompressed you can use it later with TMPGEnc, you can also crop out anything you don't want in TMPGEnc, if there are logo's etc.

But remember the final size of the frame (PAL 352x288) (NTSC 352x240 ) so if you do crop out any black borders TMPGEnc will put them back to preserver aspect ratio (Full screen keep aspect ratio)

If you chose not to keep aspect ration and make it full screen, you will stretch the frame to fit full screen, and will loose part of the image, this can also effect the quality of the movie, so its best not to use full screen.

So to recap

AVI > save out the audio and make sure its uncompressed at 44.1khz (Ready for VCD 44.1Khz)

In TMPGEnc use the WAV and AVI to encode to mpg with a VCD template, use Full screen keep aspect ratio.

Use TMPGEnc split/merge to cut the .mpg in half for each VCD

Burn 2 disk