01-07-2007, 01:21 AM

Im an amatuer video enthusiast and I've been using Final Cut Pro on my powermac G5 for some time now. For a long time i've had the most frustrating audio sync problem. Sometimes capture is ok but most of the time i'll capture a tape and go to play it back in the viewer to find that the audio is out of sync with the video by 1/2 to 1 second and its driving me nuts. I've been re-capturing tapes several times before I get a capture that is in sync. Ive had enough of it and I would realy appreciate some help from anyone who knows what is wrong and how to fix it.

Thanks

01-07-2007, 02:11 AM

I am not an expert on FCP in fact I don't even use it but I found this, regarding audio sync issues with FCP:

Getting Audio Clips Back In Sync in Final Cut Pro

24 audio items can be attached to a single video item in the timeline in Final Cut Pro or exist in a merged clip. With this being true, there are also some very complex sync relationships that can occur if you slip multiple audio items in relation to a given clip.

Three Ways To Get A Clip Back Into Sync:

- Move the clip back into sync by changing its location within the sequence.

- Slip the item back into sync (the location stays the same, but the portion of the item that is used is changed by slide-trimming.

- Mark the entire clip (even all out of sync items) as being in sync, therefore redefining the clips sync relationship.

Then I found this:

A note on audio sample rates

As much as we'd like it to be intuitive and human, FCP really is kind of a stupid machine. It can only do exactly what we tell it. It does not evaluate the data we give it, it simply re-produces that data according to how we have told it the data should be evaluated. If you tell FCP that the audio on your DV tape was recorded at 48k, when it was really recorded at 32k, it will process the audio at the wrong rate. Incorrect audio settings are the main source of out-of-sync audio and video on the timeline.

If your audio goes slowly out of sync with the picture as the playhead moves down the timeline, your settings were probably wrong at some point. It is important that you inform FCP at what rate the audio was recorded and that you keep these sample rates consistent across the application. This means that 48k audio recorded on your DV tape should be set at 48k in the capture settings and sequence settings. Not all cameras record at 48k; the venerable Sony VX1000 only records at 32k, for instance. If using this camera, you must set up your project accordingly. If you need a different preset from those provided, simply Duplicate the DV NTSC 48K Superwhite preset, select the copy, hit edit and change whatever you need to. Be sure to name it something other than Copy, since it no longer IS a copy. Consult the FCP User Manual for more details on what the rest of the settings imply.

I'm posting this in the event that it may shed some light on your audio syncing problems and hopefully lead to a solution.

01-07-2007, 06:33 AM

i dont think its a sample rate thing because when i play the scratch disk video files in quicktime they are also out of sync. perhaps i should try another camera incase it's just my camera.

01-07-2007, 05:00 PM

You would be advised to head the warning; "Incorrect audio settings are the main source of out-of-sync audio and video on the timeline". Check the settings for your camera, and then check the setup for your camera in FCP. When I've seen this question asked, this is often the problem.

The other possibility is the camera really does have a flaky problem with FCP when downloading your video.

If you have an uninterrupted segment that is very long, like a half hour then maybe you can gain more information. Here is my idea.

If the sound is out of sync by say one second at the begining and also out of sync by one second at the end, then I'd guess the camera download is just off.

if the sound is out of sync more at the end of the tape than the beginning, then I'd guess your settings are off between the camera and FCP.

I've never had this problem, but if the out of sync timing is consistent, then just shift the audio to compensate. I've done that for fireworks, as sound travels slower than light and the sounds record later than the explosion one sees.

This question may be better asked on the Apple FCP forum. You need to mention your camera model too.

01-07-2007, 05:10 PM

Originally Posted by Quantum Flux

i dont think its a sample rate thing because when i play the scratch disk video files in quicktime they are also out of sync. perhaps i should try another camera incase it's just my camera.

The fact that it is out of sync in your capture scratch quick time files leads me to believe that it is indeed a settings problem. As other people asked is it the same amount of slip through-out the clip or does it get worse and worse as the clip goes on.

I have also seen that the computer can not keep up with both at the same time on longer captures because its too processor intensive, what is the clock speed of your G5? If its one of the single core slower models then you may want to limit your capture to 20 minute intervals.

04-24-2012, 07:47 PM

Hi, this is probably a bit late, but my audio and video suddenly went out of sync as well and I was going nuts trying to find out why suddenly, after editing with Final Cut Express for a year, that everything went out of whack. I called Apple, went to a few stores, consulted a Final Cut instructor and nobody had a clue. Finally, I figured it out. I have Adobe SoundBooth installed on my Mac and I never used SoundBooth before. So one day I opened it up and it somehow hijacked my computer's sound output. So everything on Final Cut was going through SoundBooth and that's what caused the delay. To fix the problem, go to your system requirements, click sound, click output, and then make sure "Internal Speakers" is selected. Immediately after I did this, my audio was back in sync and now I'm back in business. Hope this helps!