new feature? left and right black border

[denfert]

hello,
Is it poosible to implement this functionnality.
my TV for exemple does not show 16 pixels and the right and left of the movie so i can crop this one.

with :
Crop(16,0,704,576)
BilinearResize(448,432)
AddBorders(16,72,16,72)

is it possible to choose the size of the border

Thanks

regards

[DDogg]

Yes, go to the frameserver tab, check the "edit as part of video encoding" and hand edit the avs. Before continuing, save it, find the avs in windows explorer, and view it in mplayer 6.4 to make sure you got it right. So long as you see a pic instead of a red error line you should be good to go. Don't worry if playback is slow or jerky. If you make a mistake go back and correct it. When happy just click on ok and the process will continue.

[denfert]

thanks

yes i know i done it.

It should be interesting to automatize (ou automate) this fonction. :)

[gerti67]

Hi denfert,

just saw a little mistake - i think.
If you want to cut of 16 pixels from each side of the movie then it must read like this:

=> Crop(16,0,688,576)
...

to keep the correct aspect ratio.

if you only want to crop of 16 pixels in total (8 pixels from each side) then this should be correct:

=> Crop(8,0,704,576)
=> BilinearResize(464,432)
=> AddBorders(8,72,8,72)

Greetings,
gerti67

[mkanar]

So you can't see the entire screen, so you want to just cut off that data and replace it with black?

Wouldn't it make more sense to simply make the picture just slightly smaller, then adding black borders so that you can see the entire video?

=> BilinearResize(464,464) <= multiples of 16 of course
=> AddBorders(8,8,8,8)

This will keep both the proper aspect ratio and the entire video picture while making it visible on both your television today and your television in the future (but simply with some small borders)

Also, remember that the SVCD standard is 480x480, so make certain that the resized size plus (left+right and top+bottom) borders equals 480 pixels. Sure, maybe your DVD/SVCD player works with non-compliant resolutions, but you wouldn't want to encode lots of discs, have your player break and then purchase a new one only to find that all of your old discs won't work on it. This is why I haven't ever even considered printing a disc at 48KHz.

MKanar

[gerti67]

Hi mkanar,

the problem with your method is, this is only correct for NTSC and you will get an anamorphic NTSC SVCD with it. PAL SVCD standard is 480x576, and for a 16:9 anamorphic movie to correctly show on 4:3 TV set after conversion you have to do the following:

=> BilinearResize(480,432)
=> AddBorders(0,72,0,72) <-- 432+72+72=576 to keep correct aspect ratio for PAL SVCD

your method would be like this for PAL:

480/576 = aspect ratio 0.83:1 so it must be 464x556 because 464/556=0.83 to keep correct aspect ratio.

=> BilinearResize(464,556)
=> AddBorders(8,10,8,10) <-- just fill up to 480x576 again to keep aspect ratio

The problem with it is that you add borders to top and bottom that are not necessary and you create an anamorphic SVCD. This will not happen when using the other method above. ;)

Greetings,
gerti67

[mkanar]

DOH!

"Stupid American, only sees things from his own perspective."

I can't believe I didn't catch onto that. :)

Hey, can your televisions display an NTSC signal if you attach an NTSC device?

Well, I guess my point (my american perspective? ;) ) to the true subject matter of this thread is this: Keep aspect ratio is obviously very important. So, while keeping the aspect ratio, he can either crop the frame and add appropriate borders (your method) or shrink the entire picture, giving him black borders on the top and bottom. Actually, come to think of it, I'm totally wrong because his television is obviously displaying video at the wrong aspect ratio. Well, I would encode to the spec and live with the minor loss of picture and scewed aspect ratio. But, that's just me.

I'll shut the he11 up now. :)

[gerti67]

Hello mkanar,

"Stupid American, only sees things from his own perspective." You said that. ;)

Hey, can your televisions display an NTSC signal if you attach an NTSC device? Not the regular ones - you have to buy a multi-system TV set that can play both standards or you have to buy a DVD player (or videotape recorder) that reads NTSC source and gives out a PAL signal.

...shrink the entire picture, giving him black borders on the top and bottom... yeah, but as i already said, when resizing a 720x480(576) anamorphic DVD source to a 480x480(576) - adding some little borders or not - you create an anamorphic SVCD that will show wrong on a 4:3 TV set (for this reason dvd2svcd adds borders of 60(72) lines to it - that's the point with it. ;)

...because his television is obviously displaying video at the wrong aspect ratio... No, it isn't - it's quite usual for older TV sets to do a little overscan so that some pixels on the edges get "lost" - the point is that denfert might think that this method will save some bitrate because of the black borders on the edges and he is right with it i think - but the catch in it is that you now have a lot of encoded SVCD with little black borders on the left and the right and these borders could show when you have to buy a new TV set that shows the whole resolution of 720x480(576). This can get really annoying, i think. ;)

Hope, i didn't make things more confusing,
gerti67

[Kedirekin]

One additional suggestion...

If you want to end up with 16 pixels 'cropped' on the sides, you should initially crop 24 pixels. After resize from 720 to 480, the 24 pixels will end up being 16 pixels.

For example:
Crop(24,0,672,576)
BilinearResize(448,432)
AddBorders(16,72,16,72)

[gerti67]

Hi Kedirekin,

yeah, you're right - didn't took it into the calculations. :o I usually don't crop my movies because most of the time i'm converting 2.35:1 or 1.85:1 DVDs and so there are not so many macroblocks affected as with a 4:3 full size conversion.

Thanx for the input,
gerti67

[Hodr]

I have been hanging around reading the forums for a long time, however I dont do too much svcd encoding on my own (slow system takes years to encode, and when I do I always seem to have some small problem with the final product).

Anyways, I hear lots of talk about the cropping, that its good for fullscreen ntsc films etc. but it's not exactly obvious how much should be cropped for what types of films in what situation.

Would it be to terribly hard to add a cropping section that asks what film type, then gives suggestions for the type of cropping / resizing should be used, and when selected will automadically implement it?

I know asking for added features is kinda rude, especially when you are like myself (don't use the product as often as most). But it would seem to be a good function that wouldn't be too hard to code, wouldn't be likely to introduce any bugs, and would save some people alot of time while improving the quality of their encodes.