[MEncoder-users] mencoder does not inverse telecine properly; inccorect ofps framerate

[Matt Kinni]

Hello, I have a telecined ntsc dvd that plays at 30000/1001 fps and is 6481.056 seconds long.

Mencoder's -vf pullup,softskip filters work perfectly, however I'm unable to maintain an
audio/video sync when changing the out fps to 24000/1001.

For example:

24000/1001 fps * 6481.056 seconds = 155,390 frames that should be produced by mencoder.

However,
"mencoder dvd.vob -vf pullup,softskip -ofps 24000/1001 -nosound -ovc raw -of rawvideo -o
/dev/null"
only produces 155,332 frames, which is 2.2 seconds too short (and audio/video sync fails)!

If I keep the framerate the same as the source, it produces the correct amount of frames:

30000/1001 fps * 6481.056 s = 194237 frames
"mencoder dvd.vob -vf pullup,softskip,harddup -ofps 30000/1001 -nosound -ovc raw -of
rawvideo -o /dev/null"
does indeed produce exactly 194,237 frames, the same as the source, and the audio/video
sync is ok.

The point with inverse telecining is that not only do progressive frames look nicer, but
discarding all the extra frames allows for a smaller encode.  It seams that mencoder can
inverse telecine perfectly, it just can't change the source framerate from 29.97 to the
desired 23.976.  Is there something I'm doing wrong?

Thanks for your time

-- 
Matthew Kinni
Cal Poly State University
2640 Canyon Circle
San Luis Obispo, CA 93410
Cell: 925-817-0934
OpenPGP: 0x2351657A