Audio-Video Sync Problem in Converted DVD

[satish707]

Hi,
I converted an AVI movie into a DVD but the resulting DVD has audio /video out of sync. I have tried various tools like DIKO,Vso DivxtoDVD,DVD Santa,Avi2DVD etc..Even I tried to Demux the audio and video and remux it using VirtualDubMod....but still it is out of sync....

The AVI file properties are :
AVI - Xvid Mpeg4 - NTSC 23.976fps - 640*288(2.21:1) coded @ average bitrate at 667kbps...

Audio is AC3 -ACM codec 48000 Hz, 6 channel 448kbps......
I have two such files..and i tried to join these two using VirtualDub...and then converted the Resulting file to DVD...Was out of sync...Also tried converting the files to DVD seperately....still it is out of sync....

Someone Pls help.....:(

[setarip_old]

Hi!

1) Do the .AVIs that you created play in synch?

2) If your original source material for creating the .AVIs is a DVD (I presume it is, since the .AVIs you made have 5.1 .AC3 audio), why don't you just use a program such as DVDShrink to make a backup copy?

[Matthew]

HDTV captures can have 5.1 AC3 audio ;)

Run the AC3 through BeSplit/BeSpliced and see if it reports "sync found after xxx bytes". You can also see if there is an initial audio delay using avimux gui.

[setarip_old]

HDTV captures can have 5.1 AC3 audio I learn something new every day. Thanks ;>}

[satish707]

Hi!

1) Do the .AVIs that you created play in synch?

2) If your original source material for creating the .AVIs is a DVD (I presume it is, since the .AVIs you made have 5.1 .AC3 audio), why don't you just use a program such as DVDShrink to make a backup copy?

1. --> Yup....The Avi's play in perfect sync

2. --> The Original Source for the AVI's was a DVD only...but the problem is that i dont have it now..for a backup...it was a 5.1 ch DVD only.....

Any other possibilities ???

[satish707]

HDTV captures can have 5.1 AC3 audio ;)

Run the AC3 through BeSplit/BeSpliced and see if it reports "sync found after xxx bytes". You can also see if there is an initial audio delay using avimux gui.


Hey,

Iam unable to Run the file in AVIMux GUI...Iam getting a Error Message Saying :: "MP3/Ac3/DTS source file could not be opened : the first frame header seems to be bad"

What's the problem and How to solve it....I tried to demux the Audio and convert it to MP2 and then remuxed it with the video...still the outta sync problem is there....

[setarip_old]

The Original Source for the AVI's was a DVD only...but the problem is that i dont have it now..for a backup...it was a 5.1 ch DVD only.....
Any other possibilities ???Not from me...

[Matthew]

What's the problem and How to solve it....I tried to demux the Audio and convert it to MP2 and then remuxed it with the video...still the outta sync problem is there....

If the AC3 contains corrupt frames at the start, then the avi will be able to handle this, and the audio will be delayed by the length of the junk. Once you transcode, or process/fix the AC3 so you can author it, then the junk data is lost and the desync is the result. You need to correct for this.

Delay=(junk bytes at start)/(4*bitrate) * 32
e.g. 1900/(4*448)*32=~34 milliseconds

This assumes that the junk data is at the very start of the stream only.

BeSplit/BeSpliced will tell you how many junk bytes are in the ac3 stream and where.