ntsc ivtc (29.97 to 23.97) without reencoding?

[pdx]

is this possible in virtualdub? frame decimation doesn't seem to have the ability to do a semi-ivtc (dropping every fifth frame or so) as it doesn't accept decimals in the drop every nth frame option. i'm also concerned about not dropping keyframes (the video in question is divx-encoded).

anybody tried this before? if vdub cannot solve this, is there a utility that could do this (and preferrably with a sensibility not to drop keyframes)?

thx in advance.

[pdx]

...yes, the origin of the video is FILM (24fps) which therefore should be encoded at 23.97. 29.97fps encoding of films-based materials is rather a waste of space and also causes jerky playback (at least for me).

[hakko504]

Not without re-encoding. Sorry.

[midiguy]

It is possible, but I don't think there is currently any way to do it. I am thinking that it would work by possibly implementing an IVTC filter (such as decomb) into a decoder (such as FFDSHOW), and allow you to do on-the-fly IVTC. you would probably need a lot of horse power though...

... unlessssss, it can somehow scan your movie before hand and save the frames you need (or dumped) in a log file, and then load that log file in FFDSHOW, so then all it does is play the frames listed in the log file..

but prolly not...