How would I sync audio to video in a dvd???

[Hittz]

Good morning all, I have a movie I downloaded from the net as an avi, the movie played fine as an avi, (audio in sync with video all the way through) after converting the avi to DVD format, The audio is out of sync the whole way through, here is some of the info of the vob file:

Container:

DVD "VOB" format
MPEG-2 Program Stream << { 1 vid, 1 aud }
Sys Bitrate: 10080 kb/s VBR

audio:

AC3 CBR
0xbd[0x80]:48000Hz 384 kb/s tot , stereo (2/0)

Video:

720 x 480 16:9 NTSC 29

Thanks much

[redwudz]

That's the converted MPEG format, what was the AVI format? Drop it into Gspot 2.60 and see if the little green VBR sign is lit up in the audio section. That may be your problem.

And what program or process did you use for the conversion? Was the original AVI in PAL format? PAL>NTSC conversions add a few complications.

And to the sync issue: Is the sync error the same all the way through, or does it gradually get worse? The first can be fixed with a audio offset, the second can be caused by missing frames, corrupt video, PAL>NTSC conversions, VBR audio and a few more causes. The actual problem would usually be that the audio and video are now different lengths.

It's better to determine what caused it originally, then correct it before encoding. There are some methods of fixing it after encoding, ranging from converting it back to MPEG and demuxing the file for audio adjustment, to some programs that may be able to repair it in VOB format. I don't normally do this, so I'll leave it to others to describe the processes, depending on the type of sync error and the programs used.

[Hittz]

Wow you hit it on the nose Redwudz

Original avi (in sync)


I THINK i TRANSCODED IT WITH CCE sp2 (not sure) but since then I have re-encoded the avi. I do see the vbr audio file contained in the original avi, When I transcoded it again i used Tmpgenc 4 and I did have it set to CBR the results were perfect (DVD with audio in sync) Id like to know why this happened. Any understanding that you can give me would be greatly appreciated, (ex. why it happened, how to fix it?) Thanks Much Redwudz

[redwudz]

Most MPEG encoders can't handle MP3 VBR audio without ending up with sync errors. MP3 VBR audio is very common with Xvids, and sometimes with Divx files off the net. I always assume it's VBR and check with Gspot. Or you can drop it into VirtualDub Mod and it will tell you immediately.

What I usually do for the cure is to use VirtualDub Mod and, with full audio processing, save out the VBR audio as a WAV file. Then I select that in my MPEG encoder, along with the original video. This works well with TMPGEnc encoder. Some encoder programs need muxed video and audio, if so, just mux it back with the video in VDM and do a direct stream copy of the file. I do this with ConvertXToDVD. ConvertX can handle some MP3 VBR audio, but I don't take any chances.

VDM is also handy to check for corrupted files or missing frames, which can also cause sync problems. And while you have the file in there, check the audio and video lengths to see if they match.

A third option is to convert the WAV to AC3 with a program like ffmpeggui or Aften and encode just the video to MPEG. This method also works well with CCE. Then during authoring, add the encoded video and the AC3 audio and author to DVD. I do this with TMPGEnc DVD Author, as it can accept separate video and audio streams. For authoring with programs that can't, you would need to mux it back with the video.

Mostly, watch out for MP3 VBR with Xvids as it's very common.

[Hittz]

So the cuplit is VBR in some Mpeg encoders, ah haaaaaaaaa. I went crazy trying to get this fixed. and I appreciate your help in this matter.