Doom9's Forum - View Single Post - Average plug-in : weighted average of any number of clips; fast (500 FPS on 2 clips)

mg262 · 28th September 2005, 13:10

Average, 21 October 2005

Usage is

Average(clip, weight, clip, weight, clip, weight, ... ) #YV12 clips

For example, a simple average of clips alpha and beta is given by

Average(alpha, 0.5, beta, 0.5)

And for three clips

Average(alpha, 1.0/3, beta, 1.0/3, gamma, 1.0/3)

In action:

It uses (unoptimised) iSSE if present and otherwise falls back to C. On 720x576 source, the iSSE implementation runs at 500 FPS (2 clips), 270 FPS (4 clips) and 190 FPS (6 clips) on my Pentium 4/2400. (Measured, of course, by AVSTimer.)

It is probably best to make sure the weights sum to one; the plug-in will work fine if they don't but the average may not make sense. Audio is always taken from the first clip.

This can be used as a temporal average by using arguments like:

Alpha.trim(1, 0) #next
Alpha
Alpha.trim(0, -1) + Alpha #previous

With a little script work, this can be combined with the scene detection built into Cel Background to avoid averaging over scene boundaries; I'll explain how if one of the scripters out there is interested.

This release was brought to you by the Association for the Prevention of Cruelty to TemporalSoften.

Edit: iSSE added -- read next posts.

28th September 2005, 13:10	#1 \| Link
mg262 Clouded Join Date: Jul 2003 Location: Cambridge, UK Posts: 1,148	Average plug-in : weighted average of any number of clips; fast (500 FPS on 2 clips) Average, 21 October 2005 Usage is Average(clip, weight, clip, weight, clip, weight, ... ) #YV12 clips For example, a simple average of clips alpha and beta is given by Average(alpha, 0.5, beta, 0.5) And for three clips Average(alpha, 1.0/3, beta, 1.0/3, gamma, 1.0/3) In action: It uses (unoptimised) iSSE if present and otherwise falls back to C. On 720x576 source, the iSSE implementation runs at 500 FPS (2 clips), 270 FPS (4 clips) and 190 FPS (6 clips) on my Pentium 4/2400. (Measured, of course, by AVSTimer.) It is probably best to make sure the weights sum to one; the plug-in will work fine if they don't but the average may not make sense. Audio is always taken from the first clip. This can be used as a temporal average by using arguments like: Alpha.trim(1, 0) #next Alpha Alpha.trim(0, -1) + Alpha #previous With a little script work, this can be combined with the scene detection built into Cel Background to avoid averaging over scene boundaries; I'll explain how if one of the scripters out there is interested. This release was brought to you by the Association for the Prevention of Cruelty to TemporalSoften. Edit: iSSE added -- read next posts. Last edited by mg262; 21st October 2005 at 17:09.