Quantcast KDVD: Resizing, Croping and Removegrain - digitalFAQ.com Forums [Archives]
  #1  
01-12-2005, 04:43 PM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts
Hi all, I'll need some opinions/help on this issue...

I'm trying to author a KDVD with LOTR3 and HarryPotter3. That means almost 6 hours of video that I'll fit with 2 audio streams and subtitles .
I tried a 704x576 resolution, but I had to filter and use a Q above 32, so I forgot it . To keep in DVD standard I went to 352x576.
I usually just use MATempSoftenUnfilter. But in this case, as I expected at this res to have bits to spare, i used:
LanczosResize(...)
RemoveGrain()
Deen()
to avoid blurriness. With these settings, Q=21 .

Reading the documentation of RemoveGrain:
Quote:
1. As already mentioned, RemoveGrain cannot change border pixels. To get rid of these, cropping should be done after RemoveGrain...
5. If grain is too crude, RemoveGrain can only partially remove it or cannot remove it at all. Because in such a case the source is quite poor anyway, it is a good idea to shrink. Then also the grain gets smaller and RemoveGrain may be able to erase it. In general, downsizing should be done before RemoveGrain while upsizing should be done after RemoveGrain....
But in my script I was cropping in Lanczos, before RemoveGrain...

So I decided to try this script:
LanczosResize("just resizing")
RemoveGrain()
Crop(...)
Deen()

But the tool I usually employ (MovieStacker) does calculate cropping first and resizing... so didn't help me.
I remembered of this link http://www.uwasa.fi/~f76998/video/conversion/ that Inc posted once, and figured out my numbers, with the help of Mencalc tool (also by Inc). I ended up with:
My source is anamorph 720x576, with active pixel area 720x432. My script:
Code:
LanczosResize(360,432)
RemoveGrain()
Crop(4, 56, 352, 320)
Deen()
AddBorders(0, 128, 0, 128)
LetterBox(0, 0, 8, 8)
Are these calculations right?. Following "uwasa" page resizing was 360x576, but in Mencalc, when converting 16:9 to 4:3, it changed the resizing to 360x432, and it made more sense to me (but I didn't found documentation on why this change).
With this way I lose some pixels (just 2-4) in both sides, but aspect ratio is similar to just Lanczos cropping and resizing.

Is this the correct way to follow RemoveGrain docs recomendation?. Does it worth?. Related to the output, still didn't look at it carefully, in a fast sught looked quite similar.
The samples encoded with resize-crop were 2-3% bigger: I don't know if this means more details or more "dirt" (or both! ).

Your comments/help will be of interest.
Reply With Quote
Someday, 12:01 PM
admin's Avatar
Site Staff / Ad Manager
 
Join Date: Dec 2002
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
01-12-2005, 05:00 PM
Dialhot Dialhot is offline
Free Member
 
Join Date: May 2003
Posts: 10,463
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Is this the correct way to follow RemoveGrain docs recomendation?.
Reading the doc is generally a good way . Now, to be honnest :
- Removegrain does not treat border pixels but how much pixels ? one ? two ? four maybe ? These pixels will be cut off by your screen (even with an overscan of 16 pixels). And even if they are displayer, you will see an artifact taht is in the very egde of the picture ? Eyes are focused on the action, that is the middle of the screen.

- same about order of operation : this is purely theorical and does not take in account that you have other filters atferwards in the script. Whatever is let on the picture by a Removegrain.Resize or Resize.Removegrain, it will be removed by the deen IMHO.
Reply With Quote
Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
Avisynth: RemoveGrain maurus Avisynth Scripting 3 05-16-2005 06:27 AM
Avisynth: RemoveGrain + RemoveDirt Dialhot Avisynth Scripting 29 09-20-2004 04:16 AM
Resizing for kdvd? Jimblob Video Encoding and Conversion 2 06-15-2004 07:00 AM
KDVD questions: Resizing and aspect ratios ? silverspoonjackass Video Encoding and Conversion 3 06-05-2004 02:03 PM
KDVD: Saving the Step Of Resizing? Jellygoose Video Encoding and Conversion 10 10-01-2003 09:14 AM

Thread Tools



 
All times are GMT -5. The time now is 12:04 PM  —  vBulletin © Jelsoft Enterprises Ltd