Audio Sync: 5dMK2 / Zoom H4 / NeoScene / Sony Vegas
 

So I while back I purchased a Zoom H4 for use with my 5D. I process my clips using NeoScene and it is my understanding that NeoScene converts the 30fps footage into a more standard 29.97. I’ve made a few test recording trying to sync up audio using the H4 and the 5D (and a pocket AVCHD Panasonic TS1) but have had no luck. In a very short amount of time, the audio would drift badly. I did some searching on the forums and found this post and thought it would be a great solution:

http://www.dvinfo.net/conf/canon-eos...ml#post1095886

I tried as Jon said, sync’d a clap in the beginning and end , but the audio is still drifting somehow in the middle. I’m guessing it’s user error on my part, but can anyone point me in the right direction? This same solution seems to work just fine on my Panasonic TS1, so I’m going to have to guess it has to do with the 30 > 29.97 conversion?

Unfortunately, due to a work travel, I had to return the H4 since I wouldn’t have enough time to properly troubleshoot and test. But now I have some time and want to try and get this figured out if someone can point me in the right direction.

Does anyone have a good workflow with the same setup? (5dMK2 / Zoom H4 / NeoScene / Sony Vegas)

Thanks in advance,

I had a similar problem, although I used a Fostex FR2LE. This happened during the course of over an hour of recording live theatrical events. I compared the HDV files to the rendered NeoScene files - the HDV files synced up perfectly to the separate audio files, and the NeoScene rendered files did not. Seemed to be a Cineform problem, and I never figured it out. My long-term solution was to switch to a Final Cut/Compressor solution using the ProRes codec.

I would be interested in seeing this resolved, though.

I am using a 5D Mark 2, Fostex FR2LE and Sony Vegas (with Neo HD instead of NeoScene) and am having the same drifting sync problem. I think the problem is just that the Fostex doesn't run at the same rate as the 5D. I would assume that that would be the case with the Zoom as well.

No, I don't think it's the 5D - I had the same problems with both a Canon HV20 and HV30. It seems to be Cineform - would love to here David from Cineform chime in here.

i had the same problems. Thaz y i'm looking to sync the audio from the H4n directly to the 5D/7D. However that AGC cant be defeated still unless magic lantern is used.

I took the audio track (recorded into an A1) and reduced the speed by .01 in the properties, and that seemed to do it. I have another one I'm doing in a few days so I'll post about that if I think about it.

Two digital recorders, in this case your H4 or FR2 and the camera will each be running on their 'internal clocks'. They will drift somewhat as they are not 'locked' by either a video sync reference or a digital audio 'word clock' that would be used in a professional post production workflow.
However as the 5D2 can only run for about 13 minutes in HD mode, you aren't dealing with really longterm drift issues.

I also use NeoScene, putting the files into Premiere Pro CS4 to edit. NeoScene converted audio is at 44.1k, as the original camera records, however I record the separate audio at 48k and use 48k projects in CS4. The 44.1k audio is therefore being sample rate converted by CS4. All my work however is undertaken at the 29.97 that NeoScene produces.

I put a 'guide audio mix' back into the camera from the audio recorder I use (thanks to Magic Lantern) and am therefore able to see the drift that has occured when both are on the CS4 timeline.
This drift, from both my Edirol R44 and Zoom H2 recorders is not excessive and can be corrected easily, particularly if you use the centre point of the camera 'clip' as a sync point.
I think therefore that NeoScene is not the culprit in your drift problem.
David
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