Frame Convertion

[mdorani]

how do i convert a movie which is 29fps to like 25fps and keep the sound and picture in sync?

[Wilbert]

Is your movie interlaced or telecined?

Video and audio must be done separately:

http://forum.doom9.org/search.php?s=&action=showresults&searchid=631237&sortby=lastpost&sortorder=descending

http://www.avisynth.org/index.php?page=SmoothDeinterlaceFunctions

http://www.geocities.com/xesdeeni2001/StandardsConversion/index.html#NTSCVideoDVD2PALDVD

[mdorani]

i got no idea

[Wilbert]

I suggest you learn the basic first, because it's a difficult proces. More info:

http://www.doom9.org/ivtc-tut.htm

[Doobie]

Originally posted by mdorani
how do i convert a movie which is 29fps to like 25fps and keep the sound and picture in sync?

What movie are you trying to para... I mean, what movie are you backing up in a country that allows backing up of movies? From what format, to what format, and with what software?

[pomo]

hmm.. I'm just a noob but I think this would be the proper way:

first of all, is your source truly 29.9xx fps? (beacuse if there was just used pulldown you can force 23.xxfps when converting from vob to avi (which will undo the pulldown or something like that). I usually do that in Xmpeg.) if it is true 29.9xx fps, I guess you do the following (esle you can skip the second step):

- save video and audio to different files
- convert video from 29.9xxfps NTSC to 23.xxfps NTSC Film (using IVTC or something like that)
- don't forget to slightly vertically stretch video (as PAL has more horizontal lines), e.g. from 720x480 to 720x576 (or whatever it is in your case)
- change framerate of video to 25fps (the way virtual dub does it. it doesn't change any pictures but just lets it play about 1fps faster).

ok, that way we have now correct video but audio is out of sync.
now you need to stretch (well, shorten) audio by making it play faster so its sync again with the video. (you have to calculate how much you have to speed up audio).
after that (or maybe it can be done in one pass) you also need to adjust the pitch of the audio (orelse you'll have a slight chipmunk effekt in sound).

I know this is very vague and I never did that but as far as I remember you can use Cooledit to do those sound-adjustments.

when audio and video is done just convert it into your format of choice (which I guess is mpeg2 on DVD orelse all this conversion wouldn't make sense to me).

If I am totally wrong please correct me. (and I guess there are certain things I totally screwed up and just said it the wrong way).