tv overscan area

[cow]

I read masking these hidden areas w/ black can enhance compression. But how much, on a 480x480 SVCD, can be masked without being visible on most TVs?

[ronnylov]

You can resize the picture area to 448x448 and then add black borders back to 480x480 again. The overscan area is around 10 % but it varies. But it's not the end of the world if you can see some pixels of the black border. Be sure to do it macroblock (16x16 pixel blocks) optimized to save bitrate.

I can recommend the program FitCD made by shh for this task.
http://mitglied.lycos.de/fitcd/

This is from the readme:

"Info:
======
This is a tool that helps you calculate the exact image-size and
bitrates of a SVCD.
It includes a resizing calculator for optimal (macro)block-usage in
MPEGs. You can also export a sample script for use with avisynth."

Be sure to read the readme, it has some nice tips.

[poopity poop]

I've had much experience adding borders to make the entire picture show on the TV. What the previous person said was basically true but I would suggest this:

4:3 AR
bicubicresize(472,476,.....)
addborders(4,2,4,2)

16:9 AR
bicubicresize(472,354,.....)
addborders(4,63,4,63)

When resized to a TV resolution the black borders will be almost doubled producing about 8 pixels on either side assuring that you will not see them but will get the maximum viewing from the TV.

I think those are the resolutions I'm not at my own comptuer right now. But basically you want about4-5 pixels on the right and left and about 2-3 pixels on the top and bottom added to your stream. But with widescreen you don't have to worry about the top and bottom just make sure the aspect ratio of the actual picture maintains original AR. i.e. 472/480= 0.9833, 640* 0.9833*(9/16)=354 ---472x354 when borders are added to 480x480 THEN resized to 640x480, the picture will maintain AR

[poopity poop]

the macroblock as I understood it was 8x8.
But at any rate, what I described above is only to make sure you see more of the movie and not cut off too much due to the natural cropping of a TV, and not enhancing compression....my bad

[poopity poop]

what is a macro block vs a block. I'm assuming if you look realy close that is the size of a block that you see on a wall or something will little to no detail right?
If you have a weird AR let's say 23x17 for ease of picturing. Can mpeg-2 only produce a macroblock(16x16) in the top left hand corner? Or can it shift that block anywhere it wants? Let's say if there was detail on one side vs the other could it shift the macroblock? If it can then why does it actually matter weither or not your resolution is a multiple of 16(DivX, Mpeg-1,Mpeg-2, whatever)?

[poopity poop]

Well I was a master of nandub( guess I still am). I know avisynth very well and CCE. Conversions from any format to any format, and lots of other advanced topics. But...most of you know all that also. Everyone has their specialty and there is always someone who knows more :). I sopose my main specialty is noise reduction and vdub filters.

The only real reason people know me is because I made Kenshin on DALnet in High Quality and was serving them myself via my OC3 at school. So everyone could get any episode they wanted in nandub HQ. Since then I delved into SVCD encoding and pretty much masterd that except for the hard core stuff( as you can see:) ).

But.. unfortunatly I do not know how codec compression works. and beleive me I will look at those sites, read, and understand everything they have to offer. Thanks for those sites.

[ronnylov]

Four days ago I received my new Pioneer DVR-A04 DVD-writer and now I'm trying to do this for DVD instead of SVCD. Well it seems that both 704x576 and 720x576 are valid DVD-resolutions.

But FitCD say that 704x576 is a macroblock optimized resolution when adding borders to 720x576. But how can this be true? The left black border isn't 16 pixels wide, only 8 pixels...

So I decided to use 704x576 pixels DVD-resolution (including black borders) and rezise the picture area to 672x544 (after cropping the original to 712x576). This seems to work fine and would save some bits in the encoding. Perhaps I could use 640x544 also, haven't tried it yet.

Is there any drawbacks using the width 704 instead of 720 of the full frame when making DVDs? For me it seems that this is a better resolution than 720x576 if you want an optimized encoding.

Sorry if this is posted in the wrong forum... But it's the same subject so I quess it's not that wrong?