Xena Bina
Level 1 (4 points)
Video

Q: fcpx audio and video sync & lag problems

Despite both my audio (WAV 48 kHz) and my video (.mov 48 kHz) having the same sample rate, when I match them together in the time line the audio drifts off.

Screen Shot 2016-08-31 at 16.34.43.pngScreen Shot 2016-08-31 at 16.34.57.png

 

I synched the clips myself (the automatic option is terrible), but as the clip does on the the clips drift further and further apart.

The audio clip was at 44.1 kHz, but I changed that in an external program because fcpx doesn't let me change anything!! There is no "modify settings" as was explained in another forum, and the only thing that I can change in the boxes about is the roles.

 

I have been trying to figure this out for a few days now, and my deadline is coming up. Please help me figure out how to fix the lagging!!

Thank you.

iMac (21.5-inch, Late 2012), OS X El Capitan (10.11.6)

Posted on Aug 31, 2016 1:43 PM

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Xena Bina

Q: fcpx audio and video sync & lag problems

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  • by Tom Wolsky,

    Tom Wolsky Tom Wolsky Aug 31, 2016 1:47 PM in response to Xena Bina
    Level 10 (118,081 points)
    Apple TV
    Aug 31, 2016 1:47 PM in response to Xena Bina

    Can you show the same thing for the original file? Is there supposed to be a different in duration of about 10 minutes?

  • by Xena Bina,

    Xena Bina Xena Bina Aug 31, 2016 1:51 PM in response to Tom Wolsky
    Level 1 (4 points)
    Video
    Aug 31, 2016 1:51 PM in response to Tom Wolsky

    Those are the original files as imported into fcpx. The audio was recording for the whole performance, but the video was split up into 3 pieces.

  • by Tom Wolsky,

    Tom Wolsky Tom Wolsky Aug 31, 2016 1:56 PM in response to Xena Bina
    Level 10 (118,081 points)
    Apple TV
    Aug 31, 2016 1:56 PM in response to Xena Bina

    What are the similar details for the original file that you converted? What converted it? How?

     

    Now sure what you mean by the video was split into three pieces. That one piece of video is almost three hours long. This is some DSLR camera? What camera recorded that?

     

    You synced it manually. How'd you do that exactly?

  • by Xena Bina,

    Xena Bina Xena Bina Aug 31, 2016 2:37 PM in response to Tom Wolsky
    Level 1 (4 points)
    Video
    Aug 31, 2016 2:37 PM in response to Tom Wolsky

    That's right, I did end up clipping the audio to transfer it to another timeline.

    The original audio is only 30 minutes long. The video clips were cut on the spot in in respect to the length of each performer's performance.

     

    I converted the original audio using MediaHuman Audio Converter from a .wav 44.1 kHz to .wav 48 kHz

    I recorded the audio on a Zoom H2

    The video was recorded on a Nikon D5100, 1080p24fps

    *There is another video with a roaming camera that shot short clips on a Nikon D750, shot at 1080p25fps.

     

    **A longer backstory, I put the Zoom, 5100 & 750 clips all together in one timeline which allowed the 5100 and the zoom to sync, but it left the 750 to drift. I cut the portion of the timeline that I wanted to put it in the longer video (leaving out the 750 footage), and this is when the zoom audio started to drift from the nikon d5100 footage which I can no longer fix.

    Was that followable?

     

    I'm confused as to why there is a difference in each timeline? Why is there no consistency? Why can't I change the settings in the clip?

     

    I'm happy to export clips to you if that will help to explain what is going on.

     

    I synced the clips by finding the applause in the audio of both zoom & 5100. Then I pushed the chips a few frames forwards and back to make them match correctly.

  • by Tom Wolsky,

    Tom Wolsky Tom Wolsky Aug 31, 2016 2:48 PM in response to Xena Bina
    Level 10 (118,081 points)
    Apple TV
    Aug 31, 2016 2:48 PM in response to Xena Bina

    Certainly is very confusing. No, you can just change sample rates and frame rats and such. You have to convert the files.

     

    The differences are the differences in the frame rates of the clips and the frame rate of project.

     

    Are you trying to making a multicam edit? In which case it would be best to make a multicam clip using the 23.98 clip and the converted audio. Adjust the audio in the multicam editor if you need to. They try to sync up the 25fps camera, which might be tricky.

     

    The Zoom can be set to 48K can't it?

  • by Xena Bina,

    Xena Bina Xena Bina Aug 31, 2016 3:09 PM in response to Tom Wolsky
    Level 1 (4 points)
    Video
    Aug 31, 2016 3:09 PM in response to Tom Wolsky

    Yes. I was starting organize the clips as a multi-cam edit before cutting the parts that I liked to add to the larger narrative.

    I find it difficult to figure out how to change settings. How do I change the frame rate of the project?

     

    The audio is already at 48k, but I don't quite understand what you mean by your suggestion. How do I adjust the audio in the multicam editor? And how am I supposed to sync the clips? I find a point where everything matches, but then they drift apart.

  • by Tom Wolsky,

    Tom Wolsky Tom Wolsky Aug 31, 2016 3:14 PM in response to Xena Bina
    Level 10 (118,081 points)
    Apple TV
    Aug 31, 2016 3:14 PM in response to Xena Bina

    YYou set the frame rate of a project when you make the project. You can't change the frame rate if there are clips in the project.

     

    IF the media is correct there should be no drift. Mixing frame rates will effect that.

  • by Xena Bina,

    Xena Bina Xena Bina Aug 31, 2016 3:18 PM in response to Tom Wolsky
    Level 1 (4 points)
    Video
    Aug 31, 2016 3:18 PM in response to Tom Wolsky

    Okay, so the easiest thing right now is to start a new project.

    I will try that.

    Thank you.

  • by Tom Wolsky,

    Tom Wolsky Tom Wolsky Aug 31, 2016 3:21 PM in response to Xena Bina
    Level 10 (118,081 points)
    Apple TV
    Aug 31, 2016 3:21 PM in response to Xena Bina

    Build the multicam clip first with the correct frame rate,