AssumeFPS when encoding mpeg-2 video

oso2k6 · 29th May 2009, 00:20

Hi, i have an old audio i want to add to a new video of better quality, the new video is film 24fps and the audio is in sync with the older video that is at 23.976fps. I know that assumefps only changes the duration of the video without altering the number of frames, but can this cause jerkiness or stutter if i use assumefps(23.976) to change my video from 24fps to 23.976? or is the framerate variation so low that can't be noticed? I plan to export this to dvd later. Thanks in advance.

midnightsun · 29th May 2009, 10:31

IF this new video is really 24fps and the audio was sync'ed to the old video which contained the same frames but at a rate of 24/1.001fps, then assumefps will do what you want it to. It basically spreads the exact same frames over a different time span (1.001 times longer in this case), with no duplicates, drops or blends.

PS you should really use assumefps(24000,1001) instead of assumefps(23.976)

oso2k6 · 29th May 2009, 11:16

Hi, thanks for your answer, i already encoded the video with HC using assumefps(24000,1001) and then applied pulldown to 29.97 and everything is perfect. So then i can conclude that using assumefps to slightly change the framerate like in this case from 24fps to 23.976fps is harmless?

midnightsun · 29th May 2009, 12:07

good to hear your result turns out to be as you intended it to be!
Yes, you can say it's harmless in that it doesn't mess with your video other than change its running time (in your case in a very negligible way, 0.1%)

29th May 2009, 00:20	#1 \| Link
oso2k6 Registered User Join Date: Feb 2006 Posts: 14	AssumeFPS when encoding mpeg-2 video Hi, i have an old audio i want to add to a new video of better quality, the new video is film 24fps and the audio is in sync with the older video that is at 23.976fps. I know that assumefps only changes the duration of the video without altering the number of frames, but can this cause jerkiness or stutter if i use assumefps(23.976) to change my video from 24fps to 23.976? or is the framerate variation so low that can't be noticed? I plan to export this to dvd later. Thanks in advance.

29th May 2009, 10:31	#2 \| Link
midnightsun Registered User Join Date: May 2004 Posts: 67	IF this new video is really 24fps and the audio was sync'ed to the old video which contained the same frames but at a rate of 24/1.001fps, then assumefps will do what you want it to. It basically spreads the exact same frames over a different time span (1.001 times longer in this case), with no duplicates, drops or blends. PS you should really use assumefps(24000,1001) instead of assumefps(23.976) __________________ Sorry I had to go see about a girl

29th May 2009, 12:07	#4 \| Link
midnightsun Registered User Join Date: May 2004 Posts: 67	good to hear your result turns out to be as you intended it to be! Yes, you can say it's harmless in that it doesn't mess with your video other than change its running time (in your case in a very negligible way, 0.1%) __________________ Sorry I had to go see about a girl

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29th May 2009, 11:16	#3 \| Link
oso2k6 Registered User Join Date: Feb 2006 Posts: 14	Hi, thanks for your answer, i already encoded the video with HC using assumefps(24000,1001) and then applied pulldown to 29.97 and everything is perfect. So then i can conclude that using assumefps to slightly change the framerate like in this case from 24fps to 23.976fps is harmless?