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View Full Version : convertfps making output video not "smooth"

eekeek
5th December 2006, 21:12
Video source WMV and fps = 25 (according to VirtualDub)


Clip = DirectShowSource("c:\InputVideo.wmv", fps=25, convertfps=true)

Original_Width = Width(Clip)
Original_Height = Height(Clip)

Clip = Crop(Clip, 0, 44, 0, -44)
Clip = Lanczos4Resize(Clip, Original_Width, Original_Height)

return Clip


When convertfps disabled, the video playback is smooth but sound is out of sync, but when convertfps enabled, video playback isn't as smooth as original but sound is in sync.

Anything I can do to make it better?
Fizick
5th December 2006, 22:32
Avisynth (Directshowsource) version?
eekeek
5th December 2006, 22:37
Oh sorry,

VirtualDub 1.6.17 (VirtualDub-1.6.17.zip)
AviSynth 2.5 (AviSynth_160906.exe)
foxyshadis
6th December 2006, 00:19
Look in the documentation for advanced topics, variable framerate video. I think it's hybrid.htm, maybe vfr.htm.
IanB
7th December 2006, 03:02
The more recent version of the ASF splitter used by direct show are returning bullshit stop times for each frame, typically start time + 1ms, instead of the start time of the next frame - 1, which was common when the functionality was implemented.

This effects how the convertFPS function works for VFR material. It cause the wrong frame to be repeated when undoing the VFR.

A rewrite of the convertFPS code has been scheduled. (just don't know when it will happen)