Sansgrip Filters: More Info on Legal Clip

LadyMiles · #1 11-22-2002, 03:33 AM

What "problems" do the pixels cause to the television that are out of the color range ?

SansGrip · #2 11-22-2002, 09:23 AM

Quote:

Originally Posted by LadyMiles

What "problems" do the pixels cause to the television that are out of the color range ?

That's just the way I've read about it: "problems", never anything more explicit. I don't imagine it does anything destructive, perhaps just messes up colour representation or something.

The more important benefit of using LegalClip, though, is that by clipping out-of-range colours in your Avisynth script you're not forcing the encoder to spend bits describing pixels that may not even appear on the TV set.

LadyMiles · #3 11-22-2002, 01:52 PM

Thanks SansGrip.
I was just wondering if it helped with blocky dark colors or bad gradients. So the tv scale in dvd2avi doesn't do well in making sure colors are legal

SansGrip · #4 11-22-2002, 04:47 PM

Quote:

Originally Posted by LadyMiles

I was just wondering if it helped with blocky dark colors or bad gradients.

Probably not.

Quote:

Originally Posted by LadyMiles

So the tv scale in dvd2avi doesn't do well in making sure colors are legal

Actually if you use mpeg2dec, that DVD2AVI setting is ignored. It's only relevant if you use DVD2AVI's built-in YV12->RGB conversion.

SansGrip · #5 11-23-2002, 02:39 PM

Here's a new version of LegalClip (and the source code).

The only difference is I rewrote the main loop in assembler and added SSE-optimized code for CPUs that support it (Intel Pentium III and better, AMD Athlon and better).

In other words, it's much much faster

.

Note that the SSE code will only be used if the width of the clip is a multiple of four.

kwag · #6 11-23-2002, 03:20 PM

Ahh!, I guess the automatic mirroring is working

I just checked www.kvcd.net/sansgrip/avisynth and your new "Legal" filter showed up. BTW: You bought a book on "Assembly Language Programming" a couple of days ago, because you mentioned that you had to learn assembly language. Two days later you crank out a new filter with

assembly code

Let me know what they fed you, so I can change my diet, and see if my brain can asimilate at least 10% of your speed learning

I need that bad

Great work SansGrip

-kwag

SansGrip · #7 11-23-2002, 05:53 PM

Quote:

Originally Posted by kwag

Ahh!, I guess the automatic mirroring is working

Cool -- I need to start including both addresses in the docs.

Quote:

Originally Posted by kwag

BTW: You bought a book on "Assembly Language Programming" a couple of days ago, because you mentioned that you had to learn assembly language. Two days later you crank out a new filter with

assembly code

Well it's not quite as impressive as it sounds. I did sort of learn assembler for the Motorola 680x0 chips about ten years ago, and while the Intel architecture is quite different it's conceptually the same.

Also, LegalClip is very, very, very simple. The C code inner loop is basically

Code:

if(luma_pixel < 16)
   luma_pixel = 16;
else if(luma_pixel > 235)
   luma_pixel = 235;
if(chroma_pixel < 16)
   chroma_pixel = 16;
else if(chroma_pixel > 240)
   chroma_pixel = 240;

That's about the easiest thing to convert into assembler I can think of, which is why I started with this filter

.

Quote:

Originally Posted by kwag

Let me know what they fed you, so I can change my diet

Maybe all that genetically modified food isn't such a bad thing...

vico1 · #8 11-24-2002, 07:21 AM

@SansGrip or Kwag,
where would be a good place to put Legal Clip in the script...in relation
to the placement of the other plugins? (Fluxsmooth,Blockbuster)

I found those two plugins do a great job on the movie "The Matrix"
that I`m working with now.
I`ve decided to drop NoMoSmooth when working with these plugins, as it
seemed to darken the scenes a little too much, in an already dark movie.

SansGrip, these plugins are great!..

***************************************
They can put a man on the moon,
but they still can`t put a tin pan in a microwave.......UNKNOWN

urban tec · #9 11-24-2002, 08:40 AM

Hi vico1
check this link, there is a copy of the script Kwag is using, you willsee that Legal clip is used in two places.
http://www.kvcd.net/forum/viewtopic....1604&start=105

vico1 · #10 11-24-2002, 01:07 PM

Thanks tec,
I kinda` thought I`d seen it answered before....forgot where.
(mental note).....use the search..

***************************************
They can put a man on the moon,
but they still can`t put a tin pan in a microwave.......UNKNOWN