Currently Being ModeratedMay 12, 2013 9:08 AM (in response to Matt13)
No need to "Optimize" an AIFF file. I'd not do that.
Be sure that your MP3 originals are at the video standard 40kHz sample rate. A mis-match of sample rates is the most common cause of audio drifting out of sync.
Currently Being ModeratedMay 12, 2013 9:56 AM (in response to BenB)
… are at the video standard 40kHz sample rate. …
48kHz ..... typo?
Currently Being ModeratedMay 12, 2013 10:06 AM (in response to Karsten Schlüter)
Yeah, 48, not 40, forgot I wasn't in Bizzaro World today. LOL Type-o
Currently Being ModeratedMay 12, 2013 5:50 PM (in response to BenB)
Ah gotcha. I just did some research and the recorder I'm using (Sony ICD- PX312) records at 44.1khz. There's no way to change that setting apparently according to Sony's page for that recorder. So, I guess my next question would be, the recorder only records to MP3... then I convert it to AIFF. I noticed the AIFF settings were also 44.1. I can convert it to AIFF 48khz though. Would that do the trick or would the original absolutely have to be 48khz.
I'm asking here because when I sync the files and play them back in FCPX, it plays fine. Everything is synced. It's only falling slightly out of sync after export, which takes some time obviously.
Any other thoughts or will trial and error be my only recorse at this point (or get recorders that record at 48khz)?
Currently Being ModeratedMay 13, 2013 1:52 PM (in response to Matt13)
Highlight the project in the Project Library, go to the Info section of the Inspector, bottom right is a button with the icon of a wrench. Click that. Change the audio of the Project to 44.1.
Currently Being ModeratedMay 14, 2013 10:51 AM (in response to Matt13)
Well I've tried all the potential solutions outlined here (and others I found in other discussions)... converting to 48khz had no affect on the outcome. Changing the project to 44.1 also had no change in the outcome. Even though, in any case, I get the audio synced up in the timeline, whenever I export the video file, it drifts ever so slightly out of sync after I export it to a master file. I've tried syncing audio and creating compound clips with the video's audio, all to no avial.
I'm going to get a Zoom H1 which records in 48khz (WAV) and do a 'clap' test an hour and a half long and see if I have different results. From what I'm reading, if the original audio file is recorded to 48khz, everything should sync up and export just fine. Is this true in anyone's experiences here? I'd also be interested in knowing anybody elses successful workflows (and coinciding equipment being used) with separate audio and video files.
My goal is to leave UHF over-the-air audio caputure in the past.
Currently Being ModeratedMay 14, 2013 11:03 AM (in response to Matt13)
A mis-match of sample rates is the most common cause of audio drifting out of sync.
Wireless has nothing to do with it, and is how I record everything.
You should also create a new Project from scratch, force it to 48kHz, then start dropping your media in it.
Just be sure everything has the same audio sample rate, audio files, video files, project settings, etc.
Currently Being ModeratedMay 14, 2013 11:13 AM (in response to BenB)
Yup... that's what I'm reading (mis-matched audio source files). That's why I'm hoping a device that records to 48khz solves my problems. Like I said, even after converting a 44.1khz mp3 to a 48khz AIFF, it still drifts out of sync after about 20 minutes of playback, after export (synced up fine in the timeline via adjusting the retiming of the audio file-- the videos I'm creating are up to 90 minutes long). After 90 minutes, it's probably not even more than two tenths of a second off, but just enough to hear an obvious out-of-sync echo. Again, only in the exported video file. Everything's fine in the timeline.
The video I'm capturing is from a Canon XA-10 (AVCHD), which I import and 'Optimize' in FCPX. The resulting files are Pro Res and by default are 48khz. All my projects I edit in 48khz, full HD.
My goal is to sync the standalone audio and the video-captured shotgun audio, which again, I'm accomplishing in the timeline by adjusting the retiming bar for the standalone audio, but having fall slightly out of sync when exporting to a master file. My hope is a device that records natively in 48khz will solve this issue (not an mp3 44.1 file... which is where my current dillema lays).