audio video out of sync

[puins]

I am playing a reel with around 20 clips. I notice that when the player plays a specific clip audio/video goes out of sync by around 1 second. I have checked everything and can't find out what is wrong with that clip. It has exactly the same properties as the other clips.

One strange thing I have noticed is that when the clip starts playing, I see a flash and see a frame momentarily. This frame goes away and the rest of the clip starts playing as expected. This momentarily visible frame is around 5/6 second in the clip.

I am just wondering if this unusual behavior is throwing the audio/video out of sync.

Still scratching my head and would appreciate any insight. Thank you in advace.

[setarip_old]

Hi!

I presume by "reel", you actually mean a disc.

Sounds like the clip was cut between frames.

1) With what software did you create it?

2) If you copy the problematic clip to your PC and play it from the PC, do you still observe the same problematic behavior?

[puins]

Thanks for the quick reply:

>>I presume by "reel", you actually mean a disc.
By reel I mean a AVS file that 20 clips stiched.

>>Sounds like the clip was cut between frames.

>>1) With what software did you create it?
I have basically created a avs script file and playing through WMP.

>>2) If you copy the problematic clip to your PC and play it >>from the PC, do you still observe the same problematic >>behavior?
I can play that avi file fine with WMP. I have also created a avs script file just for that clip and that plays fine too. This seems to happen when I have added a lot of avi files in the avs script and start playing it.


The avi files were created using Premiere.

[puins]

Looks like my problem is with the AVI file itself. I stiched together the same avi file 20 times in an AVS file. It starts out fine then slowly audio is out of sync. Could you please recommend me tools/strategies to solve this problem. I am a developer so don't know too much about audio/video.

I went to VirtualDub and set the audio delay track to -500. Now audio is out of sync in the begining and then looks fine in the end.

Thanks.

[Gavino]

Just a thought, but could it be simply that the audio and video in the file are different lengths - use Info() to check - and you simply need to use AlignedSplice when joining (++ instead of +)?

Also, you might want to use EnsureVBRMP3Sync (http://avisynth.org/mediawiki/EnsureVBRMP3Sync).

[puins]

I opened the avi file in VirtualDub and there is a 3 seconds diff in the audio video length. Total lenght is around 5min. Could this be the cause. When I play the avi in WMP it looks fine. When I play it in VirtualDub I see that it is out of sync.

I will now use ++ and see how it goes. Since this is more related to the quality of the video, I was thinking about just telling the person who creates the video to make it correctly. I know he is using SUPER to do the conversion. Any recommendation I should give him on that area. I know I am asking too much here but would appreciate any input. Thank you.

[puins]

I used the AlignedSplice and this seems to have solved the audio problem. Only issue I have is the system is dropping frames. I have timing codes and it is supposed to be fire at the first and lastframe which does not. Is there a specific number of frames that could be added/removed in the begining or end of the clip. Just trying to better understand how AlignedSplice works internally. Thanks.