Audio out of sync with Video...

Transco901 · #1 (**permalink**) 11-09-2006, 02:15 PM

Software: Vegas 7.0a

Source Media: .mpg file: File captured from Hi8 camcorder using ADSTech DVD Express.

Problem: The .mpg file only has the left audio channel. Attempting to recapture the video and correct this problem is not an option at this time. I used Vegas to re-render the .mpg file, using the 'Tools>>Prevew In Player' option. I chose the 'DVD Architect NTSC video stream' template, and modified it to include audio with the audio mode set to 'Mono' (not setting to 'Mono' results in an .mpg file with no audio). This worked, in so much as the both left and right channels are in the .mpg file. However, the audio is now out of sync with the video. I believe it gets progressively worse as you get farther along in the .mpg file, but not certain on this.

Is there some audio setting I need to change to fix this problem? Any thoughts/suggestions are much appreciated. I am a bit desperate here as I really want to get this work finished by this weekend.

By the way, NTSC is not a mistake (as I live in Texas). Thanks.

Andy Lockwood · #2 (**permalink**) 11-09-2006, 02:23 PM

Can't really see what (if anything) you've done wrong, but my workflow would have been as follows. I would right clcik the audio, go down the menu and select Left channel to get the sound into mono. Then highlight the entire length and render as mpeg using the DVD template. For the audio I render as AC3 and match the pair together in DVD Architect.

Transco901 · #3 (**permalink**) 11-09-2006, 03:52 PM

Ok, for the audio, 'Preview as:' is set to 'Dolby Digital AC-3'. The 'Template' value is set to 'Stereo DVD'. When I look at the properties of this template, the 'Audio coding mode:' value should be what? Stick with the the default '2/0 (L/R)' or change to '1/0 (C)'?

Thought I would ask while I'm waiting for the video to finish rendering.

Andy Lockwood · #4 (**permalink**) 11-09-2006, 06:20 PM

If you have successfully placed the soundtrack into mono, then the default will be fine.

Transco901 · #5 (**permalink**) 11-09-2006, 06:36 PM

I'm having a problem with the size of the video file. The source .mpg file is 3.03GB. When I render the video the ouput file is 4.2GB. This file alone (without audio) is already too much to fit onto a DVD. I've tried both 'DVD NTSC video stream' and 'DVD Architect NTSC Video Stream', both produce the same results (a large file). It also takes ~1 hour to complete encoding/rendering (longer than when I used the 'DVD NTSC' template which took ~30 minutes).

If I render using the the Template 'DVD NTSC', which includes audio, the filesize is much smaller and can fit on a DVD.

What gives? This is getting frustrating.

Andy Lockwood · #6 (**permalink**) 11-09-2006, 06:53 PM

Originally Posted by Transco901

...When I render the video the ouput file is 4.2GB. This file alone (without audio) is already too much to fit onto a DVD.....

4.2 will fit just fine onto a DVD and you'll be surprised how small the AC3 file will be. Also, within DVDa there is an option 'fit to disc' so if it does exceed 4.7Gb, it'll work out the overflow and reduce the bit rate accordingly to fit. There are manual options to reduce bit rate too.

Keep at it, you'll get there.

Transco901 · #7 (**permalink**) 11-09-2006, 07:54 PM

Well, when I drop both .mpg and .ac3 files into DVDa, the size used shows 4.7GB. I proceeded to the 'Customize...' button and select the 'Fit to disc' option, which popped up an error message stating that the media file(s) are too big to fit.

Also, I'm not sure how to 'pair' the two streams together as you put it. I tried dropping the files from the 'Explorer' tab onto the menu, then tried dropping them into the 'timeline' window at the bottom-right, then tried 'Import media'. In every case, the Audio track would show up on the menu as either the background or as a button. I was expecting a clear sort of 'this is the video channel, and this is it's corresponding audio channel' user interface.
I'll chalk this problem up to my ignorance with this software.

I still don't understand why a video-only .mpg file generated by Vegas is so much bigger than the original source video+audio .mpg file (4.GB vs. 3.03GB).

I'm back in the Vegas software, re-rendering the media again as DVD NTSC, with the Audio stream set to 'combine' (instead of 'left only') and the audio format on the DVD template to 'Mono'. I'm basically guessing here and trying to find a way to get an .mpg file that has video+audio in sync and can be imported into DVDa without any problems.

Anyway, thank you so much for all your help/suggestions. Much appreciated.

Andy Lockwood · #8 (**permalink**) 11-09-2006, 09:35 PM

You can set an alternative audio stream by browsing to it from the properties pane on the right hand side.

Transco901 · #9 (**permalink**) 11-09-2006, 09:45 PM

The properties of what? The properties of the button that represents the video file? I'm burning right now, so I can't check what you mean (have a dual core cpu, but don't like to touch my computer when rendering/burning).

Andy Lockwood · #10 (**permalink**) 11-10-2006, 06:34 AM

No Transco, not the button. Doing this from memory, but on the right you should have a pane that holds the media/end action/remote actions etc. In the media pane, you have the source file for the video, and below the source for the audio. Click the browse button at the right side and you can browse either source and change it.

Sorry I wasn't more specific last night, I was dog tired.