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-   -   SansGrip Filters: Sampler (http://www.digitalfaq.com/archives/avisynth/1883-sansgrip-filters-sampler.html)

muaddib 12-22-2002 09:25 PM

Re: New version 0.2a
 
Quote:

Originally Posted by SansGrip
With the current formula all you need is Sampler(). By length=1sec what I mean is length=frame_rate, which is the same thing.

Yes, I know that... but what about that discussion of the length been related to the GOP or the Framerate?

SansGrip 12-22-2002 09:45 PM

Re: New version 0.2a
 
Quote:

Originally Posted by muaddib
Yes, I know that... but what about that discussion of the length been related to the GOP or the Framerate?

Right now the sample length is the same as the GOP length, and I think it'll probably stay that way. But since Sampler has no way of knowing what the GOP length is, I decided to make the default sample length be equal to the frame rate, which right now is the same as the GOP length.

If we ever change the GOP length and decide to change the sample length along with it, then we'll have to start specifying the sample length explicitly to Sampler.

Hope that made sense :).

muaddib 12-22-2002 09:59 PM

Re: New version 0.2a
 
Quote:

Originally Posted by SansGrip
I decided to make the default sample length be equal to the frame rate, which right now is the same as the GOP length.

It's not true if your source is interlaced. I'm doing an NTSC Interlaced @ 29.970fps right now. Should I leave sampler's default, or should I set the length to 30? What will be better for the prediction? Or will it make any accuracy difference?

Quote:

Originally Posted by SansGrip
If we ever change the GOP length and decide to change the sample length along with it, then we'll have to start specifying the sample length explicitly to Sampler.

Hope that made sense :).

It sure did. :)

kwag 12-22-2002 10:05 PM

Re: New version 0.2a
 
Quote:

Originally Posted by muaddib
It's not true if your source is interlaced. I'm doing an NTSC Interlaced @ 29.970fps right now. Should I leave sampler's default, or should I set the length to 30? What will be better for the prediction? Or will it make any accuracy difference?

It shouldn't make a difference because the formula is based on the size of the GOP, which is 24 frames, no matter what frame rate you encode.

Edit: Man!, KVCD.Net is beginning to drive me nuts :lol: . I can't even go get a beer, and when I come back, I find 2 or 3 new posts 8O . I haven't even been able to visit the spanish forum today 8O . Switching over there now, brb :D

-kwag

SansGrip 12-22-2002 10:06 PM

Re: New version 0.2a
 
Quote:

Originally Posted by muaddib
It's not true if your source is interlaced. I'm doing an NTSC Interlaced @ 29.970fps right now. Should I leave sampler's default, or should I set the length to 30? What will be better for the prediction?

If the source is interlaced Sampler will use a sample length of 30, so you'll need to manually set it to 24. Right now the theory is that the sample length should always match the GOP length.

Edit: What I should have said is that Sampler will always use a sample length of 1 second by default unless you override it by specifying a length. If you know that your frame rate is not 24 (which is the value we're using right now for the formula) then you'll need to specify length=24 when you run Sampler.

muaddib 12-22-2002 10:15 PM

Re: New version 0.2a
 
Quote:

Originally Posted by SansGrip
If the source is interlaced Sampler will use a sample length of 30, so you'll need to manually set it to 24. Right now the theory is that the sample length should always match the GOP length.

oops! :oops:
That's what I mean... "Should I leave sampler's default, or should I set the length to 24?"
I just have to stop drinking... :mrgreen:

muaddib 12-22-2002 10:24 PM

Re: New version 0.2a
 
Quote:

Originally Posted by kwag
It shouldn't make a difference because the formula is based on the size of the GOP, which is 24 frames, no matter what frame rate you encode.

I got it... :D
So, if my source is 30fps, I have to set Sampler to 24 manually. Right?

note: wouldn't be better if the default was fixed to 24?

muaddib 12-23-2002 12:44 AM

Re: New version 0.2a
 
Quote:

Originally Posted by jorel
@muaddib,vou contar contigo meu amigo,help me!

Hi jorel,
Do you still need some help, or did you find your way... :?: :wink:

jorel 12-23-2002 12:58 AM

Re: New version 0.2a
 
Quote:

Originally Posted by muaddib
Quote:

Originally Posted by jorel
@muaddib,vou contar contigo meu amigo,help me!

Hi jorel,
Do you still need some help, or did you find your way... :?: :wink:

yes, need tons of help my friend, i'm really flying,
but reading (cross-eyed) and try to understand! 8O 8O :?

SansGrip 12-23-2002 01:00 AM

Re: New version 0.2a
 
Quote:

Originally Posted by muaddib
So, if my source is 30fps, I have to set Sampler to 24 manually. Right?

Yep. Sampler(length=24)

Quote:

note: wouldn't be better if the default was fixed to 24?
I was going to do that, but I really don't want to have to do a new release every time the GOP size changes. Setting a default of 24 seems rather arbitrary since perhaps others will use it apart from the KVCD crowd, so I decided that the best defaults would be samples=minutes and length=1sec. I'd rather have two defaults that are computed and useful than one default computed and the other fixed at a certain value that's useful only to us.

That was my reasoning at the time, anyway ;).

muaddib 12-23-2002 08:43 AM

Re: New version 0.2a
 
Quote:

Originally Posted by SansGrip
Setting a default of 24 seems rather arbitrary since perhaps others will use it apart from the KVCD crowd, so I decided that the best defaults would be samples=minutes and length=1sec.

It's great!
Anyway it's a lot simpler than the old way.
But you know... how about just type "S" do to the job? :mrgreen:

SansGrip 12-23-2002 09:53 AM

Re: New version 0.2a
 
Quote:

Originally Posted by muaddib
But you know... how about just type "S" do to the job? :mrgreen:

heheh yes, in theory you could: just a line with an S on it. Wouldn't be too readable though ;).

Jellygoose 12-24-2002 07:41 AM

Ok I think I got it. With the new GOP I just use "Sampler ()" ... right?
Well what's the formula then we're talking about?

SansGrip 12-24-2002 10:40 AM

Quote:

Originally Posted by Jellygoose
Ok I think I got it. With the new GOP I just use "Sampler ()" ... right?

Yep, if your source frame rate is 23.976.

Quote:

Well what's the formula then we're talking about?
I use one that's different from the canonical version, so I'd better let kwag answer this ;).

Jellygoose 12-27-2002 09:23 AM

:D No, my Framerate is 25 fps... what's the script then?

SansGrip 12-27-2002 03:10 PM

Quote:

Originally Posted by Jellygoose
:D No, my Framerate is 25 fps... what's the script then?

As the "length of sample" parameter, if none is provided, Sampler will use the movie's frame rate rounded to the nearest integer. This means that when run with no arguments on a 23.976fps 92-minute movie, Sampler will produce 92 samples each 24 frames long. On a 25fps 105-minute movie, Sampler will produce 105 samples each 25 frames long.

With the current prediction method, however, our sample length should match the GOP length we're using. At the moment our GOP length is 24 for all templates, so we want to tell Sampler to make samples with a length of 24 frames, regardless of the frame rate we're using.

To accomplish this, simply supply the "length" parameter to Sampler in this way:

Sampler(length=24)

This is of course only necessary when your frame rate is not the same as the GOP length being used.

deltaboy 12-29-2002 09:46 PM

and what scale factor are we using now in the Predictor?

0.85 is my cup o tea...

SansGrip 12-29-2002 09:50 PM

Quote:

Originally Posted by deltaboy
and what scale factor are we using now in the Predictor?

0.85 is my cup o tea...

We're currently using 1.0 in the manual formula, so that should equate to 0% in KVCDP. Let us know if you get bad results with that...

kwag 12-29-2002 09:50 PM

Quote:

Originally Posted by deltaboy
and what scale factor are we using now in the Predictor?

0.85 is my cup o tea...

With the new GOP 1-12-2-1-24, use a factor of 1.0. :wink:

-kwag

kwag 12-29-2002 09:51 PM

Cross post :mrgreen:


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