LanczosResize usage?

[snowbeach]

Have a question regarding the usage of Lanczos.

I want to encode to MPEG-2 and my question is how to resize correctly? I am confused about the LanczosResize in my .avs script, if it is correct... Thanks in advance for clearing this up, at least for me.

LanczosResize(720,368,0,48,720,368) #<- is this line correct, esp. 0,48?
AddBorders(0,48,0,64)

[AmiRage]

This line doesn't make sense as your resize target size and your crop target size are exactly the same: 720,368.

[snowbeach]

Thanks for the very fast answer! I have a NTSC source. Should it be then?

LanczosResize(720,480,0,48,720,368) #<- is this line correct, esp. 0,48?
AddBorders(0,48,0,64)

or

LanczosResize(720,368,0,48,720,480) #<- is this line correct, esp. 0,48?
AddBorders(0,48,0,64)

or should I use

crop(0,48,720,368)
LanczosResize(720,368)
AddBorders(0,48,0,64)

[Wilbert]

crop(0,48,720,368) # new res: 720x368
LanczosResize(720,368) # new res: 720x368 (thus nothing happens)
AddBorders(0,48,0,64)

# new res: 720x480
So you are basically cropping and adding the borders again. If you are doing a dvd -> dvd conversion, you don't need to do anything. What do you want to do?

[snowbeach]

I am doing a DVD->DVD conversion. The fact, why I am cropping and adding borders again was the thought to increase (maybe) the picture quality of the video during encoding, in other words not to waste bitrates on the black areas. That is why I crop (in macroblocks). What do you think?

[bewley]

If you just want to add borders, give Letterbox a try.

A simple Letterbox(48,64) would do the same thing as the crop. To save more bits, you could try doing Letterbox(48,64,16,16)... Besides the top and bottom borders, this will add borders to the far right and left hand sides of the film which usually "hide" within the TV.

Good Luck,

- bewley

[snowbeach]

I read somewhere else that if I want to keep my DVDs for a long time, I should not do any cropping or adding black borders. Because in the future, when I get an HDTV these borders would show up, so I would not be using my HDTV to its full potential. It would look just as it does when I play it on my PC.