[avisynth] how to double frame rate?

[marcorocchini]

Hi cats,

I have a source (gopro) @ 25fps progressive.
But I need an avisynth output of 50fps.

How I can double frame rate? thanks

[Cornucopia]

AssumeFPS()

[KarMa]

AssumeFPS(50) # Will double the frame rate, cut your video duration in half, and make your video twice as fast

Or you can use something like MSU Frame Rate Conversion, which can create frames by using existing frames for reference. It's not perfect and will create artifacts with low quality sources, high quality sources usually work well. There are also other better interpolaters out there but this one is a decent free one.

#Example
AviSource("video.avi")
ConvertToYV12().MSU_FRC(2, "slow") #The video needs to be YV12 for the filter to work

http://compression.ru/video/frame_rate_conversion/index_en_msu.html

[marcorocchini]

and if I use yadif(1,1) there is big problem?

[_Al_]

It was shot as 25fps with corresponding shutter speed, so changefps() seems to be appropriate in this case , I'd use that. Just doubling frame rate (and not interpolating frames) but not changing time as assumefps() would do. But it only makes sense if there is 50p needed, like mixing 50p footage, or 50p for Blu-Ray etc.
Changefps(50)

[KarMa]

I was looking for something that would just duplicate frames so thanks for mentioning changefps().

[jagabo]

Also SelectEvery(1, 0,0).