12 fps to 25 fps

[cd090580]

Hi,

I have an flv file but it was only coded with 12 fps

Now, I'd like to convert it to 25 fps. I know it won't be better but it's just to burn it to a dvd-rw and try it on tv.

Now, what's the best way => use avisynth and convert to 25 fps (so which one to use AssumeFPS, ConvertFPS,...) ???

Virtualdub ? What filters ?

Or let the encoder do the frame rate conversion ????

Thanks.

[Alex_ander]

Of those 3 (Convert, Change and Assume) ConvertFPS(25) is suitable. It will insert blended frames (created from original adjacent ones). Assume is not for this case (it would speed-up video twice) and Change would insert repeated frames (worse for motion reproduction than blending).
Maybe a simple script is possible for inserting interlaced (rather than blended) frames.
There are better tools for interpolating missing frames like MotionPerfect (commercial) or MVTools for AviSynth (http://www.avisynth.org.ru/mvtools/mvtools.html; not easy to use).

[cd090580]

Thanks.

Convert fps works.
I've tried with MVTools but it seems not to work.

here is my script:

video=AVISource("C:\Documents and Settings\***.avi",false)
audio = mpasource("C:\Documents and Settings\***.mp3")
audiodub(video,audio)
LanczosResize(704,432,0,0,480,270)
AddBorders(8,72,8,72)
Deblock()
# Conversion 12 fps => 25 fps
backward_vec = MVAnalyse(isb = true, truemotion=true, pel=2, idx=1)
# we use explicit idx for more fast processing
forward_vec = MVAnalyse(isb = false, truemotion=true, pel=2, idx=1)
cropped = crop(4,4,-4,-4) # by half of block size 8
backward_vec2 = cropped.MVAnalyse(isb = true, truemotion=true, pel=2, idx=2)
forward_vec2 = cropped.MVAnalyse(isb = false, truemotion=true, pel=2, idx=2)
MVFlowFps2(backward_vec,forward_vec,backward_vec2,forward_vec2,num=50,idx=1,idx2=2)

It crash on the last line with "System Exception - Access Violation"

[Alex_ander]

I have no experience with this tool, but it was made by trusted authors and hopefully should work after some parameter adjustment.
From what I can notice, num=50 is the output framerate; unlikely it will work for 12fps input. Maybe it also doesn't work with audio dubbed source, etc. I'd first try to repeat the author's example (25 to50).

[Cornucopia]

IIWY, I'd double the fps to 24, then speed it up to 25, as that's the way most 24fps is done in PAL-land, so it would kinda look like a "normal" film convert (would have to speed the audio up that extra 4% also).

You could interpolate/blend the in-between frames, or you could just duplicate the frames (from the preceding frame), or you could get medieval on its buttocks and do a morph/warp from frame to frame to frame to frame (take a very long time, though ).

Scott

[cd090580]

I've retried with MVTools, I did an error on last line.

Now when I try to open it with Vdub or play it in WMP 11 it display an new error: "System Exception - Invalid instruction at 0x0" ??????

[Alex_ander]

Here's an example of my working conversion 12.5=>25 using the author's template (mvtools.dll auto-loaded from 'plugins' folder):

source=DirectShowSource("E:\Transfers\Video\Who\Pe te_Townshend_-_2007.06.02_ITA__I_Can_t_Reach_You_.wmv",fps=12.5, convertfps=true)
# assume progressive PAL 12.5fps source
backward_vec = source.MVAnalyse(isb = true, truemotion=true, pel=2, idx=1)
# we use explicit idx for more fast processing
forward_vec = source.MVAnalyse(isb = false, truemotion=true, pel=2, idx=1)
return source.MVFlowFps(backward_vec, forward_vec, num=25, den=1, ml=100, idx=1) # get 25 fps

Works great, no complaints.