Trouble Syncing P2 24p footage with 29.97 audio

[Jeff Brown]

Are you sure both frame rates are the same? Because typically, video will actually be 23.98 FPS. If your audio is true 24.00 FPS (which it could be), there’s your problem. I’d fix it by re-timing the audio in Audition or similar app.

-Jeff

[Arlo Ihrig]

Hi Jeff,

Thanks for your reply.

Here’s the meta data for the video and the audio files. I don’t fully understand the 29.97 pulldown to 24P (though I’ve been watching to videos to try to understand it better), and I’m not sure how this effects the timecode exactly(obviously it does somehow), if the result is that are both supposed to be 24fps in the end.

Type: P2 Movie
File Size: 1.5 GB
Image Size: 1280 x 1080
Frame Rate: 29.97 (24p)
Source Audio Format: 48000 Hz – 16 bit – Mono
Project Audio Format: 48000 Hz – 32 bit floating point – Mono
Total Duration: 00:01:48:20
Average Data Rate: 13.7 MB / second
Pixel Aspect Ratio: 1.5

Type: Windows WAVE audio file
File Size: 15.3 MB
Source Audio Format: 48000 Hz – 24 bit – Mono
Project Audio Format: 48000 Hz – 32 bit floating point – Mono
Total Duration: 00:01:51:05328
Average Data Rate: 140 KB / second
Sound Dev: 744T S#461007017005
sSPEED=023.976-ND
sTAKE=1
sUBITS=$01151201
sSWVER=2.67
sPROJECT=
sSCENE=15-2
sFILENAME=15-2T001_2.WAV
sTAPE=120115
sTRK2=Track B
sNOTE=

[Arlo Ihrig]

I have a little bit of an update:

I figured out a work around based on someone’s suggestion – I found the difference in samples using the audio display, and found that if I sync my clips using timecode, then nudge everything by +2200 samples the audio matches nicely – but I don’t like having to do this.

This is a real pain in the butt and I’ve now spent my whole weekend trying to get this to work. I’m really hoping Adobe will have some insight into this and either a fix/suggestion or something. Its added a couple steps to my workflow – and I’m just working on the dialog with 4 channels – glad I don’t have more.

[Jeff Brown]

Is it possible to genlock the video and audio systems? They have to be connected/synchronized somehow, or you will most likely have drift (as you found).

-Jeff

[Arlo Ihrig]

Well, the footage has already been shot, so I’m trying to do clean-up at this point. It does seem there is a small discrepancy in the length of the external audio, by several samples, maybe 2200/48000ths smaller.

This is really driving me nuts, but I guess I don’t have anything else but manually adjust them all to be somewhere in the middle to hide the drift. It probably won’t be noticeable to anyone but me.

But I have to think Adobe would know something about this, and I haven’t heard back from them on this.

[Jon Frost]

Arlo:

Looks like your clips are really shot in 29.97 not 24p which would be 23.976.
Your audio was recorded at 23.976.

Rerecord your audio in Audition at 29.97. Make sure your Sequence Preset is set for 29.97.

You can use PluralEyes for syncing the audio to video, though you have to futz around with the settings depending on the quality of your camera audio (scratch track only) and your SD744T. I normally use Level Audio, Try Very Hard and Multiprocessing.

Jon Frost