Video/Audio timelines not lining up (Audio at 30fps)

cortex bug
1

I got a weird one for you. A production shot video at 23.976, recorded audio at 30fps. Cameras were not jammed so video TC does not match audio TC. Manually syncing audio to video for one of the first clips (to hopefully get an offset). I find the slate clap, click A1 to select matching audio WAV file. Find the spike in the audio, hit D.

So now Cortex has found the sync point in both the audio and video. However, the timeline at the bottom is woefully off. The fields for Picture Sync and Sound Sync have correct timecodes, but the timeline at the bottom (blue bar for video, waveform for audio) has the video/audio lined up almost 90 seconds apart.

Also, the Preview window shows the wrong audio TC compared to the actual audio TC.

Really weird to describe in text. So here’s a screenshot. This is in Cortex 1.5.2 b5004.

I used Wave Agent and converted one audio file from 30fps to 23.976fps and experienced no trouble.

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2

I haven’t been able to reproduce this yet. I tried 23.976 picture with 30 fps audio and a very large offset between the two. There must be something I’m missing…

3

I just made another project and got the same results. Let me send you the files I have via FTP and you can test. Total material is about 5GB.

Edit: files are uploaded

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4

OK, I can confirm that I see the issue with the files you sent. Will update here when we have a fix.

5

Seems to be some combination of the timecode rate being different and the offset being so large and in the ‘negative’ direction (as inferred by Cortex’s fuzzy timecode math).

As you found changing the source audio timecode rate to 23.976 fixes it.

But instead changing the timecode start time from 14:53:36:04 to 12:53:36:04 also fixes it…

6

should be fixed in v1.5.3 beta b5081

7

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