Avisynth: Changes for MA Script for 528x480/576 Resolution?

audioslave · #1 07-07-2003, 05:59 PM

Hi kwag and all,
From what I understand the MA script is optimized for resolutions from 528x480/576 and up? What changes do I have to make to the script if I plan encodes at 352x240/288 or 480x480/576? Maybe a stupid question...

kwag · #2 07-07-2003, 06:03 PM

Hi audioslave,

The only change needed should be the value for switching between blurring and Temporal filtering.
Look at the line: ScriptClip("nf = YDifferenceToNext()"+chr(13)+ "nf >= 2 ? \
And change the >= 2 to >=4
That should basically take care of 352x240(28

.
For 480x, I think that a value of 3 should be pretty close to ideal.
Give it a try

-kwag

audioslave · #3 07-07-2003, 06:09 PM

@kwag,
Thank you for your fast reply as always! What parameter am I tampering with if I'm changing the value you described? I mean, what does it do?

kwag · #4 07-07-2003, 06:14 PM

The value you are tampering with is the value to compare the returned value from the function "YDifferenceToNext()".
The less activity, the lower the value and vice versa. So it's really a "treshold" trigger point to switch between the blurring line "unfilter( -(fmin(round(nf)*2, 100)), -(fmin(round(nf)*2, 100)) )" and the Temporal line "TemporalSoften( fmin( round(2/nf), 6), round(1/nf) , round(3/nf) ,1, 1)"

-kwag

audioslave · #5 07-07-2003, 06:21 PM

Thanks again! I was just curious. So what will happen if I use the value for 528x480/576 if I'm encoding 352x240/288 for example?

kwag · #6 07-07-2003, 08:12 PM

Quote:

Originally Posted by audioslave

Thanks again! I was just curious. So what will happen if I use the value for 528x480/576 if I'm encoding 352x240/288 for example?

The value returned by "YDifferenceToNext()" will be different for different resolutions, so you'll be switching filters at non-optimal activity values. You can easily see the value of "nf" variable (the treshold variable) if you insert this line at the end of your script:

Code:

ScriptClip("Subtitle(String(nf),1,30)")

This way you can tune the treshold point by loading your script in Vdub, and sliding to different parts of your movie. Try it

-kwag

vico1 · #7 07-08-2003, 12:37 AM

So for fine tuning using a 1/2 DVD Rez, (352x480 ntsc) a value of >=3 or 4 sounds
about right, depending on the movie?

*******************************
The Devil`s always.....in the Details!

Fiz · #8 07-08-2003, 08:13 AM

Kwag,

Is it possible to use a formula to derive this threshold based on the width of the clip?

I have tried the following code and it assigns the threshold based on the current width of the clip.

Code:

DifferenceThreshold = (Width<=352) ? 4 : (Width<=480) ? 3 : 2

ScriptClip("nf = YDifferenceToNext()"+chr(13)+ "nf >= DifferenceThreshold ? \ 
unfilter( -(fmin(round(nf)*2, 100)), -(fmin(round(nf)*2, 100)) ) : \ 
TemporalSoften( fmin( round(2/nf), 6), round(1/nf) , round(3/nf) , 1, 1) ")

The reason I do "<=" is that the overscan parameter of GripCrop will reduce the width so it may be less than 352 etc until GripBorders runs. I used your example (below) to view the value:

Code:

ScriptClip("Subtitle(String(DifferenceThreshold),1,30)")

and I can see the value changing for each resolution I choose. This way the script can be automated further or do you think this would impact performance?

Cheers,

Fiz.

kwag · #9 07-08-2003, 10:28 AM

Quote:

Originally Posted by Fiz

Kwag,

Is it possible to use a formula to derive this threshold based on the width of the clip?

Yes

Quote:

I have tried the following code and it assigns the threshold based on the current width of the clip.

Code:

DifferenceThreshold = (Width<=352) ? 4 : (Width<=480) ? 3 : 2

ScriptClip("nf = YDifferenceToNext()"+chr(13)+ "nf >= DifferenceThreshold ? \ 
unfilter( -(fmin(round(nf)*2, 100)), -(fmin(round(nf)*2, 100)) ) : \ 
TemporalSoften( fmin( round(2/nf), 6), round(1/nf) , round(3/nf) , 1, 1) ")

The reason I do "<=" is that the overscan parameter of GripCrop will reduce the width so it may be less than 352 etc until GripBorders runs. I used your example (below) to view the value:

That's's correct, and it must be done that way to consider overscan blocks

Quote:

Code:

ScriptClip("Subtitle(String(DifferenceThreshold),1,30)")

and I can see the value changing for each resolution I choose. This way the script can be automated further or do you think this would impact performance?

Cheers,

Fiz.

Hi Fiz,

You just reminded me of what I did a long time ago to automate Blockbuster noise levels, depending on resolution

Your lines are perfect, and just made it to the current script

I'm updating it right now

Thanks,
-kwag

Fiz · #10 07-08-2003, 10:53 AM

Quote:

Originally Posted by kwag

Your lines are perfect, and just made it to the current script
I'm updating it right now

Cool

kwag · #11 07-08-2003, 10:59 AM

Hi Fiz,

Script posted

I only changed the variable name "DifferenceThreshold" to "SwitchThreshold", because it seemed more appropiate for the description

I just tried it on a one minute clip, and there are no speed penalties with or without the changes

Probably because it's just comparing constants

-kwag

Fiz · #12 07-08-2003, 11:12 AM

Thanks kwag, being the novice I am I've learnt so much from this forum, not to mention the high quality encodes I'm churning out these days! I'm just glad to be part of it!

TLTw · #13 07-28-2003, 05:29 PM

Code:

DifferenceThreshold = (Width<=352) ? 4 : (Width<=480) ? 3 : 2

if i understand that right if its <=352 it assigns a 4 if <=480 a 3 and all else is assigned a 2 ?

kwag · #14 07-28-2003, 05:41 PM

Quote:

Originally Posted by TLTw

if i understand that right if its <=352 it assigns a 4 if <=480 a 3 and all else is assigned a 2 ?

Yep

-kwag

DKruskie · #15 07-28-2003, 07:12 PM

I have been using the current MA script with 352x240 resolution since it came out and it looks great on my tv. I didnt know I had to change any values for 352x240

David