filter for virtualdub: framerate

[benderman]

For 1CD-ripps I try to reduce al unneccessary parts to the minimum but want to keep the full length. For intro/outro it would be usefull to do a fake framerate reduction so that only every second framechange is shown while the real framerate still is as the original. If I didn't explain it correct maybe this will help:

I take this video:

frame1 frame2 frame3 frame4 frame5 frame6 frame7 frame8 ...

and get this:

frame1 frame1 frame3 frame3 frame5 frame5 frame7 frame7 ...

Specially for scrolling outro-text it would only use a little more than half the bitrate. I think there is a method if I use avisynth, but is there any filter for virtualdub?

[khp]

You can use the decimate filter to throw away every other frame.
Don't know if there is a frame doubleing filter also, and Donald Grafts page is down atm so I can't check it right now.

Another clever trick is to do a fake frame size reduction.
First chop the pictue down to a resolution X*32 or so, and then use the resize filter to extend it back to the original resolution. This will add some huge black borders, which of course compress very well.

[benderman]

Yes, I allready chopped an added black borders or simply used a still picture instead of the whole endcredits, but I think the framerate-thing could give better results on some videos. Still searching ...