audio / video sync

bbrooks wrote on 12/20/2004, 6:48 PM

I have separate audio and video sources from a recent concert video that some friends and I recorded of a band that I play with. The audio was recorded to an mp3 player/recorder (Archos Jukebox) using the analog input (two stereo mics through a small mixer).
The video was recorded to:
Camera 1 - Sony DV
Camera 2 - 8mm video cam
Camera 3 - VHS C
Camera 4 - VHS C
The Sony DV and Audio match up the best but are slightly out of sync by the end of the video (approx 50 mins).

All of the Analog was capture going through the AV/DV converter in the camera going into the computer using a firewire hook up (as was the DV of course). Why are the analog recordings so far off from the video by the end. Even the audio of each camera winds up being out of sync with each other by the end of the show.

Comments

John_Cline wrote on 12/20/2004, 7:07 PM

It's because even though all the devices have crystal controlled clocks, none of the clocks run at EXACTLY the same speed. Outside of "genlocking" all the devices, which means running them all off a single master clock, there isn't much you can do about it.

John

bbrooks wrote on 12/20/2004, 7:18 PM

Thanks John. What's my best option then? Should I just sync up one song at a time perhaps?

John_Cline wrote on 12/20/2004, 7:53 PM

Yes, they probably stayed in relatively close sync for at least a song. Assuming this was a band with a drummer, you can just line up all the cameras and the audio on the timeline using something like a snare drum hit. It should be relatively easy.

John

bbrooks wrote on 12/20/2004, 7:56 PM

Too funny! I'm the drummer and that's the first thing I look for instinctively.
Thanks John
Brandon