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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: neutrino on November 12, 2024, 08:26:44 PM

Title: Audio sync issues with Final Cut Pro ??
Post by: neutrino on November 12, 2024, 08:26:44 PM
I have a video recording I'm trying to sync external audio to without success. I'm using Final Cut Pro. The video is from 1993 and was recorded on 8mm video and recently transferred via Canopus ADVC100 to my MAC. I transfer the 8mm video at 1440 x 1080p at 29.97i. The original camera audio was recorded without an external audio microphone so the audio is totally blown out and distorted. I have good analog external audio recorded with a Sony D5 transferred as a WAV at 48khz. Any of the DAT's I have from back then sync right up with the video but does anyone have a way I can get this analog source to sync? I have tried to do it manually with FCP by lining up the WAV forms but it almost immediately looses sync.
Title: Re: Audio sync issues with Final Cut Pro ??
Post by: jefflester on November 12, 2024, 09:06:18 PM
Sounds like the D5 (or the playback deck, or both if not the same deck) is off speed, so you'll have shrink or stretch it to get it to match. Just like folks trying to matrix two audio files like a SBD cassette and an AUD cassette.
Title: Re: Audio sync issues with Final Cut Pro ??
Post by: neutrino on November 12, 2024, 10:36:41 PM
Im assuming there is no automated way to do that within FCP. Anyone know of any automated way to do that with any program? I’m guessing I would have to export both audio files into another program to get them to match and then bring the WAV files back into FCP.
Title: Re: Audio sync issues with Final Cut Pro ??
Post by: nulldogmas on November 13, 2024, 12:22:45 AM
Im assuming there is no automated way to do that within FCP. Anyone know of any automated way to do that with any program? I’m guessing I would have to export both audio files into another program to get them to match and then bring the WAV files back into FCP.

Yes, that's exactly how to do it. It's pretty easy in Audacity: Get both tracks aligned at their start, drop a marker in each at the same moment near the end of the track (something short and loud like a snare hit is good), select everything from the start to that marker in the each track, and copy the timestamp of the marker in the blown-out track into Change Speed and Pitch > New Length in the track you want to get to align with it.
Title: Re: Audio sync issues with Final Cut Pro ??
Post by: guitard on November 13, 2024, 09:00:03 AM
Sounds like the D5 (or the playback deck, or both if not the same deck) is off speed, so you'll have shrink or stretch it to get it to match. Just like folks trying to matrix two audio files like a SBD cassette and an AUD cassette.

One small caveat.

If it truly is just a matter of consistent off-speed drift throughout the recording, then shrink/stretch will work great.  But a lot of times with these old analog recordings, there are other problems like: a little drop out somewhere, or only part of the tape drifts, or the whole tape drifts - but not at the same speed throughout.  I could name a few other pitfalls that await those entering this rabbit hole!  But I think you get the idea.  8)
Title: Re: Audio sync issues with Final Cut Pro ??
Post by: RyanJ on November 13, 2024, 08:19:11 PM
I read through this thread and just want to make sure you are using the option of selecting both the audio and video file you would like to sync, right click and press 'synchronize clips.' Inside the parameters before it syncs is a box that says 'synchronize with audio.' This should work.

If you are using this and you're still having issues. There are definitely dropped frames somewhere in the video recording. Which could make it very problematic for a shift. Which seems like a big pain in order to sync video and external audio.
Title: Re: Audio sync issues with Final Cut Pro ??
Post by: neutrino on November 13, 2024, 11:19:07 PM
I read through this thread and just want to make sure you are using the option of selecting both the audio and video file you would like to sync, right click and press 'synchronize clips.' Inside the parameters before it syncs is a box that says 'synchronize with audio.' This should work.

If you are using this and you're still having issues. There are definitely dropped frames somewhere in the video recording. Which could make it very problematic for a shift. Which seems like a big pain in order to sync video and external audio.

I did this exactly and still had no sync. All the videos I synced with DAT audio synced right up, by not the first time I tried it from an analog external audio source.