Convolution3d Compressibility Check

[JohnMK]

Any ideas on how I can compare the compressibility of convolution3d'd movies vs. non-convolution3d'd? I'd like to do this in GordianKnot using as much of its built-in features as possible. Suggestions please?

Thank you. :)

[iago]

@JohnMK

To use/test convolution3d, you have to edit your avs script and load convolution3d.dll first. You can use "trim" in your avs script to select a short part of the movie and run your tests with and without convolution3d (just like you would do with any other external filter).

regards,
iago


just for example (all the paths and parameters should be changed of course ;)):

script1
-------
LoadPlugin("C:\PROGRA~1\GORDIA~1\mpeg2dec.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\convolution3d.dll")
mpeg2source("D:\MOVIE\MOVIE.d2v")
Trim(15000,18000)
crop(2,5,716,467)
convolution3d(0,4,4,4,4,3,0)
LanczosResize(640,352)


script2
-------
LoadPlugin("C:\PROGRA~1\GORDIA~1\mpeg2dec.dll")
#LoadPlugin("C:\PROGRA~1\GORDIA~1\convolution3d.dll")
mpeg2source("D:\MOVIE\MOVIE.d2v")
Trim(15000,18000)
crop(2,5,716,467)
#convolution3d(0,4,4,4,4,3,0)
LanczosResize(640,352)


If you gonna use constant quantizers, file sizes will give you an idea about compressibility.

If you wanna test using two-pass, run debugview and then analyze/compare the quantizers.

[JohnMK]

I'm aware of that. What I'm unaware of is how to make it easy to use, considering I'm very used to the standard 'Now' compress check in Gordian Knot. I found a LastCompCheck.avs file in C:\program files\GordianKnot. If I edit that and add in my convolution3d parameters, how can I have it use that for the compress check, and not overwrite it with a new one?

[sh0dan]

Try asking in the G-knot forum instead, since it's more a question of Gknot functionality.

[JohnMK]

In your script I see you're cropping by and resulting in odd numbers prior to resize! :-o I thought that was forbidden?

Point taken about comparing file sizes with constant quantizers. I'll see what I come up with. I just wish there were an easier, built-in way (GordianKnot).

[iago]

Originally posted by JohnMK
In your script I see you're cropping by and resulting in odd numbers prior to resize! :-o I thought that was forbidden?@JohnMK

No man, it's not forbidden! ;) Unless the resizing method or the filter(s) you use require cropping to be done by multiples of 2, 4, 16, etc.

regards,
iago

P.S.: If you have a "normal film - DVD" source, I wouldn't suggest using values higher than convolution3d(0/1,6,6,6,6,3,0) unless your source is quite noisy.

[Acaila]

@iago:

When you crop in odd numbers:
- The worst that can happen is you get artifacts.
- Even if all filters can handle it perfectly they will still interpolate information (which is also not a good thing).

To avoid both, always crop in even numbers.

[sh0dan]

Horizontally that is true, but vertically it shouldn't matter. If filters doesn't support it, they should throw an error, otherwise they're buggy!

[ohliuv]

@JohnMK

for compressibility test with divx5 check this thread (http://forum.doom9.org/showthread.php?s=&threadid=34610)

200/(average quant) will give you approximate %

[soujir0u]

Hiya, just add this line to the bottoms of your avs:

SelectRangeEvery(280,14)

And encode the avs with Vdub or something. Then, open GordianKnot and press the Load button on the Bits/Pixel*Frame box and load your stats file. Oh, and I think this method only works for Divx3.11 and XviD.