laserfan
6th December 2007, 21:49
Under what circumstances might Avisynth/VDub/Xvid duplicate frames in its output, from a progressive (VC-1) 2.40:1 source?
If I load this .avs into VDub
DirectShowSource("movie.grf", fps=23.976, framecount=206236, audio=false)
Crop(0,140,0,-140)
Lanczos4Resize(1280,534)
and then Save As an .avi compressed w/Xvid HDTV profile (no Vdub filters at all), the beginning of the movie (the Warner logo "spin") has some duplicated frames which results in jerkiness. Oddly, I can't find this problem anywhere else in the avi--it's only at the very beginning!!?? Also, the duplicated frames appear at the expense of the original frames i.e. the frame it should have compressed is now missing, and the total frames in the movie stays the same, 206236, so when I re-mux the audio it's always perfectly in-sync.
When I do a frame-by-frame step-thru of this script w/Vdub, the output always looks like it's going to work fine, but then I do a Save As and the very same frames are duplicated every time.
Note that originally I made an Xvid without the Crop line above, and just Resized to 1280,720 and no frames were duped--it came out perfect. Any ideas?
If I load this .avs into VDub
DirectShowSource("movie.grf", fps=23.976, framecount=206236, audio=false)
Crop(0,140,0,-140)
Lanczos4Resize(1280,534)
and then Save As an .avi compressed w/Xvid HDTV profile (no Vdub filters at all), the beginning of the movie (the Warner logo "spin") has some duplicated frames which results in jerkiness. Oddly, I can't find this problem anywhere else in the avi--it's only at the very beginning!!?? Also, the duplicated frames appear at the expense of the original frames i.e. the frame it should have compressed is now missing, and the total frames in the movie stays the same, 206236, so when I re-mux the audio it's always perfectly in-sync.
When I do a frame-by-frame step-thru of this script w/Vdub, the output always looks like it's going to work fine, but then I do a Save As and the very same frames are duplicated every time.
Note that originally I made an Xvid without the Crop line above, and just Resized to 1280,720 and no frames were duped--it came out perfect. Any ideas?