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View Full Version : Can't get original GH2 audio in sync in Vegas



potatolaces
01-21-2013, 04:30 PM
Hi! What's happening?

So, I've got this very annoying problem and I don't know what the cause is. This problem is getting me in trouble because I'm trying to make a music video. Let me explain:

Everytime I import a file from my GH2 into Sony Vegas, the original audio doesn't seem to sync up with the original video it is attached to.
Example: I recorded myself clapping my hands. When I match the video and audio with the first clap, it seems fine. But then, when I clap for the second time, the video/audio is out of sync AGAIN! When I try to sync up the video with the second clap, it doesn't sync up with the first clap anymore. This happens with every clap. It becomes really slightly out of sync. This is really confusing because my timeline settings are matching with my footage settings.

When I watch the original footage in WMP, it IS in sync.

What can this problem be?

I really need help!

potatolaces
01-22-2013, 02:49 AM
Nobody?

David Jimerson
01-22-2013, 12:06 PM
Which version of Vegas?

TheDingo
01-22-2013, 12:28 PM
How long are the video and audio tracks?

Depending on which recorder I use for audio, I can be out as much as 18 frames over an hour of GH2 video. ( I have one recorder that is almost a perfect match to my GH2, where the sync will be out only 1-2 frames every hour )

troelskirk
01-22-2013, 12:46 PM
Do you zoom in a LOT on the timeline when matching the two claps? The sound of the clap can be between two frames of 1/24th sec, so it will look slightly out of sync when enlarged. I have never experienced sync trouble with my GH2's internal mic sound in Vegas Pro 11 at least... My Tascam recorder will drift ever so slightly...

TheDingo
01-22-2013, 02:22 PM
Do you zoom in a LOT on the timeline when matching the two claps?

I don't shoot like most people do. For interview work I will slate the camera and recorder at the start and then let the camera and recorder run for a VERY long time ( sometimes hours ) and then slate again at the end.

In Sony Vegas I CTRL + DRAG the audio clip to match the exact timing of the front and tail slates, and then use the G ( group command ) to lock the video and audio tracks together. Then I export the video track with the new adjusted audio track as one of my processed video files. I visually correct gamma, white point, black point, contrast, saturation. Then I process the audio with EQ, compression, noise-reduction, and adjust to get perfect sync. And once all of this is done I export using the Cineform 10-bit 4:2:2 CODEC as one of my main files to do the actual edit with. ( I want all of the correction BS out of the way when I edit )

I will sometimes shoot Indie work the same way, except that every take is slated so it's easy to find each take by the slate's audio spike.

troelskirk
01-22-2013, 10:35 PM
The question was not about external sound recorder sync, but the camera's built-in mic sound... I agree on clapping or slating every take with an external recorder though... good idea with an end slate on long takes!

TheDingo
01-23-2013, 06:26 AM
The question was not about external sound recorder sync, but the camera's built-in mic sound...

Then I guess I'm a little confused on what the problem is that you are referring to?

There is the known issue where all DSLR cameras record the audio track 1-2 frames ahead of the image: DSLR Audio: Do YOU know where YOUR sync is? (http://provideocoalition.com/awilt/story/dslr_audio_do_you_know_where_your_sync_is)

And this is an easy manual fix in most editors, where you have to manually sync the audio to be frame accurate, which is easier to do if you let the camera run and slate every take within one long video recording.