digitalFAQ.com Forum - AVISynth+ deinterlacing out of sync?

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Greenieman

11-09-2025 09:13 AM

AVISynth+ deinterlacing out of sync?

I've been trying to figure out how to use AVISynth for a while now, but my main problem this whole time was that audio wasn't synced up. My workflow is capturing with AmarecTV with Lagarith Lossless Codec, deinterlacing with AVISynth, and capturing and rendering with VirtualDub64.

The script I'm using:

Code:

SetFilterMTMode("QTGMC", 2)

AVISource("nuttybuddy.avi")

ConvertToYV12()

AssumeTFF()

QTGMC(preset="Slower", Edithreads=7)

BilinearResize(720,540)

Prefetch(26)

The audio is in sync for a bit, but then goes out of sync later on. How can I fix this issue, or any others that may be in the script?

Aya_Rei

11-09-2025 09:34 AM

Is the audio in sync for the raw file?

Hm, maybe try to QTGMC code Hushpower gave in this thread

Code:

QTGMC(Preset="Fast", FPSDivisor=1, EdiThreads=2) #FPSDivisor default is 1 gives double framerate; 2 gives orig FR

Greenieman

11-09-2025 09:44 AM

Yes, in the interlaced version it is, also that didn't seem to change it. Also, I'm not sure if this is it, but the video is being rendered at ~58-60 fps, but the video says it's 59.365 fps? I thought it was supposed to be 59.94 fps.

mts1	11-09-2025 04:55 PM

Greenieman, how did you know the original file was properly synced?
Did you use VirtualDub to play it back?

Greenieman

11-09-2025 11:14 PM

The original interlaced video was synced and I checked by looking through the video and it always stayed in sync with the audio, the issue starts when I watch the AVISynth preview, and after, when I export using VirtualDub, it is out of sync the same way the AVISynth preview was.

mts1	11-10-2025 07:51 AM

Could you elaborate, what exactly does it mean "checked by looking through the video"?

Greenieman

11-11-2025 10:11 PM

The original interlaced video that I got from AmarecTV before trying to deinterlace it with AVISynth, has it's audio in sync the whole time, no matter where in the video, it is in sync. But the deinterlaced version of the footage from AVISynth starts in sync, but gradually becomes out of sync.

mts1	11-12-2025 02:20 PM

Quote:

Originally Posted by Greenieman (Post 105268)

Greenieman, how about you try script with just one line:

Code:

AVISource("nuttybuddy.avi")

If the result will be out of sync, then your original capture file is out of sync.

vwestlife

11-12-2025 03:14 PM

Use MediaInfo to make sure the original file is 29.97 or 59.94 fixed frame rate, not variable frame rate. If it is variable frame rate, then you probably dropped frames during the capture.

Greenieman

12-20-2025 09:19 PM

I apologise for the wait, I've been busy, but yeah it says nothing about variable framerate from Mediainfo for the original interlaced file. Also, are you THE vwestlife?

lordsmurf

12-21-2025 08:46 AM

Quote:

Originally Posted by mts1 (Post 105279)

Greenieman, how about you try script with just one line:

Code:

AVISource("nuttybuddy.avi")

If the result will be out of sync, then your original capture file is out of sync.

Yes, do this. :thumb:

Quote:

Originally Posted by Greenieman (Post 105687)

Also, are you THE vwestlife?

Yep.

Greenieman

12-27-2025 01:40 PM

I think it's still dropping frames, just in the interlaced version it's less noticable. I haven't tried capturing with VirtualDub yet so I might try that.

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