Time Stretch to maintain sync

[Mark0514]

We are shooting with a consumer grade camcorder that doesnt have line input. I am recording the audio on a PC and pulling it into Vegas Movie Studio. I can sync the front end, but about twenty minutes in it's out of sync. Someone mentioned time stretching, but I'm not familiar with it.

Anyone have any ideas?

[cmchamp]

For future reference, you should make sure you are recording your audio at the same sample and bit rate that are set in Vegas in it's settings.
For our annual Easter drama, I record 4 cameras of video, 24 tracks of audio at 48/16 with no sync issues over the two hour production.
C.

[Mark0514]

Vegas is telling me that the wav is 48,000Hz 16 Bit. That matches the .mts file I am pulling in. I went back and look at the track in audacity, and the sample format was set to 32bit float, not 16bit PCM. Would that cause this issue, even though the export is 16 bit?

[cmchamp]

possibly. Was the original in Audacity set at 48kHz?

[WORDpictures]

Soundtrack Pro that comes with Final Cut Pro will easily stretch or condense the audio track length without altering pitch. You could probably find someone to assist to correct a special project, but not a good permanent fix.

[waynehoskins]

Seems like synchronizing all of the recorders with timecode would be the best solution, though probably not practical in your case. The even better option would have both audio and video recorded on the same machine, also not practical in your case.

[Mark0514]

Originally Posted by cmchamp

possibly. Was the original in Audacity set at 48kHz?

Yes it was. I dont think I could use a time code, unless both recordings started at the exact same time. I figured out how to stretch/shrink without altering the actual content, and it seemed to work fine on the 20 minute clip. If it gets longer there may be any issue, but I could always export 20 minute wav files and stretch them as needed. Definitely not the optimum situation, either. I will double check the settings on my audacity next time, as well.

Thanks!

[[Director] Joseph B]

Originally Posted by cmchamp

For future reference, you should make sure you are recording your audio at the same sample and bit rate that are set in Vegas in it's settings.
For our annual Easter drama, I record 4 cameras of video, 24 tracks of audio at 48/16 with no sync issues over the two hour production.
C.

It's always easy when you know how! I'm just going to start "toying" with video and I'm sure that information will come in handy at some point.

[jksbc]

Originally Posted by Joseph B

It's always easy when you know how! I'm just going to start "toying" with video and I'm sure that information will come in handy at some point.

Ditto! Audio is the only thing that concerns me about getting into video editing. Just not sure how it all works :P