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Old 18th June 2010, 08:06   #10  |  Link
Motenai Yoda
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Join Date: Jan 2010
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~#these are my personal considerations
mdegrain or mvdegrain shoud be used with the correct aspect ratio (aka par 1:1) and should be used as one of the last filters (if after of resize) or used after an upsample of only one side to achieve the correct ar (if before of resize).
Quote:
Originally Posted by fizick
> The reason for which I disturb you is a discussion that I am having
> with some rippers. The discussion is reassumed in my following
> affirmations:
>
> 1. The motion must be analyzed on the image the more similar to the
> final one.
>
Probably yes. But remember I do not understand what do you want to do
> 2. VOBs are anamorfic; MVtools work with PAR 1:1, therefore the same
> quantity of motion is otherwise valued, depending on its direction;
> MVtools don't give precise results when used with anamorfic images.
>
Yes, PAR is 1:1 in MVTools.
> 3. An analysis of motion must be done on the final cropped image, so
> that not to include pixels not contained into the final active image.
>
Yes. You may even crop a little more to scip block near borders.
> 4. Null speed in front of very fast movements (or scene changes) is
> not an anomaly, but a limit of MVtools. This situation can rise up
> after the crop, but only because the useless part of the pixels (black
> borders) has been eliminated.
>
Probably you know about thSCD1 and thSCD2 parameters.
> 5. It seems that you have said (the source is not verifiable) that the
> analysis of a native VOB is the fastest method to perform the analysis
> with MVtools; in base to my measurements, an analysis done after the
> filters ColorMatrix(), Spline16Resize(640,256,0,78,0,-78) and
> Limiter(16,235,16,240) is faster than 35%.
>
> Some rippers affirm that the analysis of movement is more efficient
> and fast on VOBs, in contrast with my point of view that I have just
> reassumed you.
>
I never said this. MVTools do not use any direct information from VOB. Question is not-correct. You may resize to 2048x1526 for example and you will got extra slow MVTools processing.
> I would like to know your opinion in the hope that your patience and
> gentleness are superior to my ability to explain me in a language that
> I know bad.
>
I do not speak English well too. I understand your message but I do not
understand your goal.
> Last but not least: I would like your permission to publish this
> letter on that public board, together with your possible answer.
>
no problem with it. But my answers is almost empty
fft3d contrariwise imho should be used before resize for better precision, or next to resize.

DCT, RemoveGrain, undot at the end to improve their increase of compressibility (depending of the rest of script).

Last edited by Motenai Yoda; 18th June 2010 at 08:16.
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