Sync audio with 25p video

S

Sepand

Member
Today I'm gonna shoot a concert with 2 DVX100s and the audio will be recorded separately.
To avoid the problems which may occur later, I wanted to know which settings I should ask the audio man to change, is it just the sampling rate or is there anything else?
Thanks
 
Different TC's don't affect sampling rate. Have him record in 25fps if you are trying to match TC but unless you have a slate or are recording TC to the DVX' audio channels TC won't help. If you record TOD TC then that can get you a close approximation.

Good luck
 
Pretty much yes, ask the sound recorder to record at 48khz then make sure the project's sound track is set to 48khz as well. There will be no problems syncing them.

But some times the sound track can fall out of sync. Simplest solution is to place a cut every 5 minutes on the audio track. Shift each clip along by what ever amount of time needed usually a few frames will do. This is not ideal but unless you can sync TC by sending TC to the recorder and use a TC slate this method will do.
 
Coldpizza said:
Pretty much yes, ask the sound recorder to record at 48khz then make sure the project's sound track is set to 48khz as well. There will be no problems syncing them.

But some times the sound track can fall out of sync. Simplest solution is to place a cut every 5 minutes on the audio track. Shift each clip along by what ever amount of time needed usually a few frames will do. This is not ideal but unless you can sync TC by sending TC to the recorder and use a TC slate this method will do.
Click to expand...

With DV, timecode only serves to establish a single sync lineup point in exactly the same manner as a manual slate clap does. It does nothing to preserve sync and prevent drift over the course of a long'ish shot. Audio and video can still drift out of sync even if one sends camera TC to the audio recorder (assuming one is using a camera that has TC output). To prevent drift, one needs to slave the audio recorder's sample clock to the camera's video sync clock so they're locked together. This is easiest to do if one has a recorder like the Tascam HD-P2 that accepts video blackburst, otherwise we get into the world of genlock and Lockit boxes, good solutions but not cheap.
 
Coldpizza said:
Pretty much yes, ask the sound recorder to record at 48khz then make sure the project's sound track is set to 48khz as well. There will be no problems syncing them.

But some times the sound track can fall out of sync. Simplest solution is to place a cut every 5 minutes on the audio track. Shift each clip along by what ever amount of time needed usually a few frames will do. This is not ideal but unless you can sync TC by sending TC to the recorder and use a TC slate this method will do.
Click to expand...

A "few frames" every five minutes is a HUGE drift. The most I have ever seen with digital recorders not locked together is around a frame or so in twenty minutes. Usually one can go an hour or two and have a near insignificant drift. But a lot depends on the devices being used and how stable their clocks are.
 
Sepand said:
Today I'm gonna shoot a concert with 2 DVX100s and the audio will be recorded separately.
To avoid the problems which may occur later, I wanted to know which settings I should ask the audio man to change, is it just the sampling rate or is there anything else?
Thanks
Click to expand...

Are you posting in 25P? If your speed is not changing through the project you don't need to change sample rates.
 
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