Synch Problem

[King-Of-DK]

Is there anybody who can tell me,how i can correct the audio synch on an Mpg file after conversion with TempGenc?
The AVI file seems ok,but every time i convert the sound gets delayed 2 seconds.I have tried to use virtualdub,and it seems to correct the AVI,but i am not sure which compression to use,in both sound and picture..

[willem]

When it's a constant delay throughout the whole film, try dumuxing it and remux it using bbMPEG. You can specify a delay there.

[King-Of-DK]

OK,there doesn´t seem to be a tab called demuxing or remuxing in bbMpeg,if there is i can´t find it..

[homerpez]

What I would do, actually, is if you still have your source video/audio, re-encode with TMPGenc first, but this time apply the "Source Range" filter. Then set your in/out frames, and in the middle where it says "Audio Offset", play with it (in ms) until the audio is in synch (do a short test clip where people are talking). I think a positive value here adds delay to the audio (imagine the audio starting later) and a negative value lowers the delay (imagine having the audio start earlier).

Then, once the ENCODE is in synch, then definitely run the whole thing through bbMPEG to remux (most players like this product a whole lot more than TMPGEnc alone).

The reason I'd say not to use the audio offsets in bbMPEG is because it can cause a sudden cut-off of audio at the end of a file.

Maybe this won't matter to you, like if you do a whole movie, but I did a mess of cartoon episodes on a VCD... I managed to get the audio slightly out of synch during the encode process. I was able to fix using bbMPEG, but at the end of each episode, the audio ended before the video by almost a second (since bbMPEG only had the short video clip's audio as source, it ran out of material). If you get it right first in the encode process, you usually have more to work from (TMPGEnc will move the whole audio stream around, so you get the whole thing).

Sorry if I took that a little too far.

P.S. almost forgot. You don't demux with bbMPEG, you go in TMPGEnc under "Simple Demultiplex" and choose your .mpg file. There's no indicator to show it's working, so don't panic. Just wait for the hourglass to change back to your pointer (it could take a minute or two)

<font size=-1>[ This Message was edited by: homerpez on 2001-08-21 03:38:59 ]</font>

[King-Of-DK]

Thanx,homerpez,the trouble i have is that there doesn´t seem to be a "tab" or something like that,that says remux,in this bbMPEG thingy,as you can see i am a newbie.I have found out that i can reencode the AVI file in Virtualdub,with the audio in synch,the problem is,that i have no clue as to what compression i should use in both the audio and picture,but i have tried to reencode some 64 seconds,and then avi2mpeg with tempgen,and that seems to work,the original AVI is app. 720mb,and my reencoded one is only about 580mb,i use the DIVX compression for audio 16bits 44.100khz stereo for divx,and i use the compression fast motion divx for the picture.Do you have any comments on that??

[willem]

The multiplexing is sort of hidden in bbMPEG. For a howto including pictures goto http://www.doom9.org. Select "The Guides" -> "VCD&SVCD Guides" -> "DVD2AVI" -> "TMPG Guide" and see step 8a (demultiplexing using TMPGEnc) and 8b (Multiplexing this again with bbMPEG).

Hope this helps.

[King-Of-DK]

Thanx, Willem,will this fix the synch problem,by it self,or do i have to set the time the sound has to be delayed?? Does this work with all movies with the audio synch problem?? I have problems of the same nature in 3 other movies,and the out of synch is throug the whole movie..

<font size=-1>[ This Message was edited by: King-Of-DK on 2001-08-21 05:58:09 ]</font>

[willem]

bbMPEG allows you to set a delay time. I suppose negative delay times are possible. Never tried it so it's trial and error. It's worth trying and relatively fast. If it works try the other films as well. If it doesn't look further by using the search function of this forum. There are quite a few audio sync posts.

_________________
Regards,

Willem

<font size=-1>[ This Message was edited by: willem on 2001-08-21 06:45:25 ]</font>