sound is out of sync after render (edit) ASAP

eGabimpact wrote on 5/23/2013, 1:53 PM
I have imported a large amount of clips into sony vegas from DVD camcorder disk. I have edited out parts of clips and have them ready on the timeline to burn. I render the audio as AC3 and video MPEG2 dvd architect NTSC video stream. Once I bring the files into DVD architect and preview them, or burn a DVD, I notice the sound is not in sync with the video. This hasn't happened with all the files I've done this way. I've successfully burned 15 DVDs that are 2 hours and full of different clips, no sync problems.
The issue is with a handful of files, were certain clips get out of sync with the corresponding audio. Sometimes the audio will go back on track throughout the DVD when a new clip starts.
What it looks like to me is some clips are rendering and sped up a little because the quality of the video isn't that great and the program seems to be dropping frames to get rid of those issues and towards the end of that clip, there is no more video so it inserts a black screen while the audio is still playing at the pace it was supposed to be.
It doesn't seem like a frame rate issue to me (though it is still possible). I am hoping it's just a rendering setting box that I have to uncheck.
I have only just started using this program a month or two ago and don't have a lot of expertise on video editing in general. So if you could try to simplify or be specific on where to change settings that would be very much appreciated. Using Sony Vegas Pro 12.0.

Comments

musicvid10 wrote on 5/23/2013, 2:02 PM
A preview is just that.
Go ahead and prepare your DVD and play the folder in VLC.
You will know then if there is an actual sync problem.
eGabimpact wrote on 5/23/2013, 3:20 PM
I rendered the video and audio "within loop region only" and the final rendered length of audio is 1:51:08.535 and the length of the video is 1:51:09.463.
The preview of other successful projects have all appeared in sync and I didn't have this difference in length.
eGabimpact wrote on 5/23/2013, 3:33 PM
I have tried viewing a prepared file in VLC and the out of sync problem is there.
musicvid10 wrote on 5/23/2013, 11:19 PM
Then you've likely got some indexing problems with your source. Run all the gathered clips through the Quickstream Fix utility in VideoRedo Plus first (there is a free trial). If you're "just" stitching them together do that in VRD+ too. If you're actually editing, the processed clips should do much better in Vegas than they did.

I "assume" they are all at the same frame rate? There are some potential problems if they're not.
eGabimpact wrote on 5/28/2013, 10:34 AM
I have put a lot of work on about 5 projects editing out parts of clips, transitions, etc. I would rather try other things before starting again with the original clips. I've done 20+ other projects without this problem. I think it might be because of the original source of the clips is different. They came from VHS transfers, and different camcorders starting in the early 90s. The section I've having trouble with are from the mini DVDs that were around for a couple years. There is a chance the frame-rates on all the clips are not the same. I'll see if I can figure out how to check that. Like I said, they play just fine in the timeline in sony vegas, but once I render, the sound slowly goes out of sync. On one of them it adds in a black screen for over a minute and the sound is still playing from the previous clip.
wwaag wrote on 5/28/2013, 10:52 AM
Just an idea. Render your audio track as a wav file and then add it to your timeline above the original. Then visually compare your waveforms. Perhaps this will give you some idea as to where the two waveforms become different.

wwaag

AKA the HappyOtter at https://tools4vegas.com/. System 1: Intel i7-8700k with HD 630 graphics plus an Nvidia RTX4070 graphics card. System 2: Intel i7-3770k with HD 4000 graphics plus an AMD RX550 graphics card. System 3: Laptop. Dell Inspiron Plus 16. Intel i7-11800H, Intel Graphics. Current cameras include Panasonic FZ2500, GoPro Hero11 and Hero8 Black plus a myriad of smartPhone, pocket cameras, video cameras and film cameras going back to the original Nikon S.

eGabimpact wrote on 5/28/2013, 2:03 PM
how do I find out if the frame rates of the clips are all the same? I think that might be what is wrong. Does that mean they can't go into the same project? or do I have to render each section separately?
eGabimpact wrote on 5/29/2013, 1:55 PM
That is a really good idea. I think it is an issue with the way it's rendering though. The sound stays right on track, it seems like the video is being sped up slightly when it's rendered leaving me with a black screen at the end of each clip while the sound is still playing. This doesn't happen to every clip in the timeline though, just certain ones.. usually the ones that have static and bad transitions originally recorded on the video camera.