MPEG>DVD audio problems

cutter wrote on 2/7/2005, 7:43 AM

I captured an 88 min movie from Beta machine via a winfast 2000xp capture card analog input. Resolution was set at 640x480, using an mpeg2 codec.The resulting file was just under 5gigs.
I created the dvd...several times, in fact, each time trying to solve the same problem; the lip sync was way out. After the third coaster it occured to me that although I was optimizing the video and compressing it to fit on the dvd, I wasn't actually able to adjust the audio, which is probably where the error is. Am I missing something...is there a trick to this? I thought that the embedded audio in the mpeg file would be compressed at the same ratio. Do I need to capture the audio track as a separate file in order to compress it as well?
Any suggestions would be greatly appreciated.

Comments

ScottW wrote on 2/7/2005, 7:50 AM

This is a real common problem when you capture to MPEG. Convert the file to AVI and try to resync things with Vegas, or better, don't capture to MPEG, capture to DV AVI (maybe your camcorder has an A/V input and will let you do this).

cutter wrote on 2/7/2005, 7:59 AM

Thanks...I'll give that a try!

bStro wrote on 2/7/2005, 8:01 AM

My immediate guess is that you need to change the settings you're using to capture. For starters, 640x480 is not an acceptable resolution in DVD Architect (some DVD players will do it, but it's not in the official DVD specs, which is what DVDA follows). This wouldn't necessarily lead to audio synch problems, but it does mean that DVDA is re-encoding this video every time you try to make a DVD from it, and that's just wasted time. ;-)

Also since your capture program is using a resolution generally used for computer viewing (640x480) rather than one used for DVDs (720x480), I suspect that it's also using a lower sample rate for tha audio than is needed for DVDs. The audio should be recorded at 48,000 Hz, whereas computer / CD audio is generally 44,100 Hz. If you give DVDA audio recorded in the wrong samplerate, it will re-encode it to the right one, but the sync will probably get messed up in the process.

Bottom line: Check your capture software for a "DVD compliant" setting. Things will probably go smoother if you use the settings I listed above. If the quality of the original video isn't all that great to begin with, you can bump the resolution down to 352x480 in order to save space, but set it at 720x480 if your source is good. Whichever you capture at, be sure to set your DVD project to the same. (But still set your menus to 720x480, because lower res menus can be wonky.) These resolutions, by the way, assuming you're making an NTSC disc -- they'll be different for PAL.

As long as your'e fiddling with those capture settings, see if it will use Variable Bit Rate -- it may cut that MPEG size down some.

Rob