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View Full Version : avisynth dropping frames during vdub encode?


srhlefty
17th May 2003, 06:10
Hi, I've been using avisynth scripts to frameserve mpeg-2 files into virtualdub and subsequently convert them to avi's. However, after examining the number of frames virtualdub claims the mpeg-2 has, and comparing it with the number of frames virtualdub claims the output avi has, I find a discrepency of about 30 frames. Normally for one file this is no big deal--but I am eventually appending about 10 of these files together, which at 60fps (I'm deinterlacing the source) has been causing the audio to desync with the video to a noticable degree.

What is the nature of this problem, and can it be solved? The source is 720x480 NTSC interlaced, which I am deinterlacing and resizing with the following script:

loadplugin("C:\Program Files\GordianKnot\MPEG2DEC.dll")
mpeg2source(".\d2v_mpa\05162003-01.MPG.d2v")
BicubicResize(640,480,0,0.75)
Bob

The avs is then opened in virtualdub, the appropriate audio file selected and delayed accordingly, and video compression set to divx.
As of this writing I was not able to access avisynth.org, so I apologize if a similar question has been asked already.

I would appriciate any input. Thanks for your time!

--UPDATE: it seems as though it drops exactly 31 frames from the end every time. Ring any bells?

Steve

sh0dan
17th May 2003, 09:38
1) Be sure to use DVD2AVI 1.76.
2) Use mpeg2dec3.
3) Bob BEFORE resize.

srhlefty
17th May 2003, 19:16
-I'm already using DVD2AVI 1.76 (command line version)
-I downloaded mpeg2dec3.dll and included it in my avs files, but upon loading it in virtualdub I get an error saying it is not an Avisynth 1.0 plugin. Yet I have already installed Avisynth 2--maybe I installed it wrong?
-Changed my avs files to bob before resize.


Steve

TelemachusMH
17th May 2003, 19:34
You have to use AviSynth 2.5x to use mpeg2dec3.dll. It doesn't work wiht AviSynth 2.0x. You will get that error if you try using it with the 2.0x versions.

TelemachusMH

srhlefty
17th May 2003, 20:02
You're right, I was using avisynth 2.08. I downloaded 2.5.1 beta, and everything now works. The number of frames now matches in the original and output avi--Thanks guys!

Just a random trivia, I have been using a single batch file to convert many mmv files all the way to avs scripts, thereby eliminating Sony's MovieShaker from the picture entirely.

Once again, many thanks.

Steve