View Full Version : Convert Framerate WITHOUT interpolation
YaBoyShredderson
22nd February 2021, 21:20
im using staxrip to convert some variable framerate footage from my phone to constant framerate prores to be edited, but i cant work out how to change the framerate without interpolation? all i want to do is convert the framerate without changing the runtime. if i convert using x264/5 and change the frame rate in those settings, it just speeds up/slows down the footage. with prores, there is no framerate setting, so i have to use avs. I click on framerate, click on convertFPS and then select what i want it to be, but it interpolates to that framerate, i realised when i read the readme in the files for staxrip. how do i get to change the framerate without interpolation? handbrake can do it, but not to prores.
poisondeathray
22nd February 2021, 21:25
ChangeFPS will duplicate or drop frames to achieve the desired framerate without changing the run time (rounded to nearest frame because you can't have fractional frames)
(ie.. the interpolation is duplicating frames instead of blending frames)
Sometimes the source filter can be used to do this as well (e.g. ffvideosource, fpsnum, fpsden)
YaBoyShredderson
22nd February 2021, 21:36
ChangeFPS will duplicate or drop frames to achieve the desired framerate without changing the run time (rounded to nearest frame because you can't have fractional frames)
(ie.. the interpolation is duplicating frames instead of blending frames)
Sometimes the source filter can be used to do this as well (e.g. ffvideosource, fpsnum, fpsden)
I have no idea how to use avs in staxrip, what do i need to put into the avs window to get the desired result? There is no change fps option.
StainlessS
22nd February 2021, 22:07
It kinda depends a bit upon your script, and target rate.
ChangeFPS(25.0) # 25 FPS, with default special un-named implicit Last clip as source, implied assign result to special Last clip
ChangeFPS(24000,1001) # 23.976 FPS (numerator,denominator)
# ...
src.ChangeFPS(25.0) # 25 FPS, with named source clip, implied assign result to special Last clip
src.ChangeFPS(24000,1001) # 23.976 FPS (numerator,denominator)
# ...
dst = src.ChangeFPS(25.0) # 25 FPS, with named source clip, and assign to dest clip
dst = src.ChangeFPS(24000,1001) # 23.976 FPS (numerator,denominator)
ChangeFPS() on Wiki
http://avisynth.nl/index.php/FPS
Wiki Main Page:- http://avisynth.nl/index.php/Main_Page
YaBoyShredderson
22nd February 2021, 22:14
It kinda depends a bit upon your script, and target rate.
ChangeFPS(25.0) # 25 FPS, with default special un-named implicit Last clip as source, implied assign result to special Last clip
ChangeFPS(24000,1001) # 23.976 FPS (numerator,denominator)
# ...
src.ChangeFPS(25.0) # 25 FPS, with named source clip, implied assign result to special Last clip
src.ChangeFPS(24000,1001) # 23.976 FPS (numerator,denominator)
# ...
dst = src.ChangeFPS(25.0) # 25 FPS, with named source clip, and assign to dest clip
dst = src.ChangeFPS(24000,1001) # 23.976 FPS (numerator,denominator)
ChangeFPS() on Wiki
http://avisynth.nl/index.php/FPS
Wiki Main Page:- http://avisynth.nl/index.php/Main_Page
Im using staxrip, which uses avisynth. I dont know how to write dcripts or anything like that. I only click and add the stuff i want in the box that says avs box.
StainlessS
22nd February 2021, 22:19
Well as I still have less idea than you about what you are doing [ie what framerate are you aiming at],
try either the first or 2nd optional lines given [altering for your target rate], if whole number of FPS, then 1st one, else 2nd.
EDIT:
If 29.97, then
ChangeFPS(30000,1001) # 29.97 is not the exact number, numerator,denominator provides as near as possible.
EDIT: or if 59.94 then
ChangeFPS(60000,1001) # 59.94 [59.94005994005994005994005994005994005994005994005994005994 ... 005994 ... ]
YaBoyShredderson
22nd February 2021, 22:30
Well as I still have less idea than you about what you are doing [ie what framerate are you aiming at],
try either the first or 2nd optional lines given [altering for your target rate], if whole number of FPS, then 1st one, else 2nd.
EDIT:
If 29.97, then
ChangeFPS(30000,1001) # 29.97 is not the exact number, numerator,denominator provides as near as possible.
I think i worked it out. I tested with 24000/1001 source converted to 60000/1001, and i went into vlc and checked frame by frame, and it appears to be doing a 3:2 pulldown, which means its not interpolating like before. I wouldnt do this conversion in real life, but it was an easy test. Thanks.
StainlessS
22nd February 2021, 22:32
Oh good, as an afterthought I added that too [59.94].
Glad you got it sorted.
EDIT: You can put
Info
at the end to see what the result is.
vBulletin® v3.8.11, Copyright ©2000-2026, vBulletin Solutions Inc.