23.98 Footage From A-1 Audio out of Sync
 

I captured a 60 minute interview shot in 24f on the Canon A1 using Cineform Prospect HD's appropriate capture setting in PPro 2.0. The audio, as the interview goes along, becomes more and more out of sync. What am I missing? I don't use 24f much...

Cheers.

Is you timeline in 24.0 or 23.976 mode? If you had scene breaks, you should capture with scene detect on, otherwise audio sync can occur in the breaks. If you are monitoring using an AJA Xena card, make you use the CineForm ASIO audio driver to use the AJA audio, to lock audio sync. Otherwise it sounds like a good question for support, file a ticket at www.cineform.com/support.

I used the 1920x1080 Cineform preset that is called 24p but when you look over at the details it does say 23.98. I will double check the PPro 2.o project settings.

When the tape is played out through the HV20, both the A1 footage and the HV20 footage, which was both 24fps setting, the audio is fine. Is it because those are both being played from a tape and embedded in a 60i stream? And then when captured they are put in a 23.98 project the video duration is different but the audio stream is the same? This probably never shows up in clips of only a few minutes, but we had to shoot running non-stop 60 minute segments and it gets really bad in the final 2/3.

Anyone else have any thoughts?

David:

Is it because I didn't change the audio rate in the Cineform Capture settings? I shot this on tape at 24 f, so....should I select any of the audio change settings?

No audio change is required, 23.976 in camera is converted 1:1.

David. Not sure what to do. I submitted a ticket. I need to send the client a preview DVD of the interviews by Wednesday and audio out of sync will be a wee bit of a problem :)

The odd thing is that when played from camera to a monitor the audio is fine all the way through.

You going to have to do you our testing. Work out how much the audio is off and speed change the audio to fix it. The amount of speed change will be a clue as to why you audio is off, plus you will have a fix your client.

David:

That's fine I will work on it. In the short term, since the footage plays fine from camera to monitor (I assume at 29.97 since it is coming directly from tape), does it make sense to capture the 23.98 footage into a 29.97 timeline? Will the extra repeat frames be put back in therefore esentially making it match the audio speed? Does this makes sense? If so, is there a way to do that with one of the Cineform presets?

Sorry, that does not make sense. No native 24F media should not be put in a 60i timeline, as it doesn't have pulldown, and Premiere will not add it for you (it will frame blend.)

Work out how you audio is off and fix that directly. The amount of speed change required be the clue we need. If you play at the end of the timeline, is it out of sync, or does it only go out during playback?

Note: This should be handled by tech support.

Looks like there were a few places where a drop frame occured. That is where the audio became out of sync. Again, these are long 60 minute running interviews.

Anyone have advice how to minimize dropped frames in really long capture sessions? I have never had drop frame problem before. Does it make any sense to capture the video and audio separately? Does that type of approach help the impact on the system (or am I out of my mind that it will help at all)?

I would, first and foremost, clean the heads on the deck or camera you are using to capture. I would then clean the heads on your cameras in the field, if different. Most dropped frames in my experience are due to dirty heads when writing to tape on location, and is irreparable. However, dirty heads can also lead to dropped frames on capture, if it has trouble reading the tape.

Also, make sure you have no unnecessary background processes eating up memory and hard drive I/O that you need to capture the file.

Honestly, though, every time I've had dropped frames, it came back to dropped frames on the tape during capture, and as such, unrepairable. :(

Carl