Screen Size

[jimbo79]

can any one help please.
for pal vcd's 352x288 is for 4:3 screen size.

can some one tell me the size for 16:9 please,
this concerns capture size when ripping wide screen DVD's.

thanks.jim.

[Dr Mordrid]

I would think 352x198. (352/16=22 ; 22*9=198)

Dr. Mordrid

[jimbo79]

screen size

Thanks Doc will try that,But if you lower the hight dont you have to widen the screen?
Does just changing one dimension change the overall picture area?
this is wierd to try and work out as I can't seem to work out a common denominator between 4:3 ratio and try to change it to 16:9.
I will try you size and see what happens...
thanks Jim.
PS. I'm in uk so on PAL...

[zeb7]

The way i worked it out was from the DVD spec's
The DVD spec's for Anamorphic DVD conversion (by the player)
Decode the mpeg2 frame (2 fields) = 720x576
Squash to 720x432
add black boarders of 72 pixels to top and bottom

So as VCD is 1 field 288 pixels
it should be 216 pixels with black boarders of 36 pixels to top and bottom.

[Dr Mordrid]

Ahhh...you're in PAL LAND...that makes it different. I was thinking in NTSC. I'd go with 216 in that case.

Dr. Mordrid

[jimbo79]

thanks guys for your support, will try said setting and choose something I'm happy with... Jim..

[Technoid]

One thing to think about is the fact that many "16/9" movies is still 720*576 (pal)!

The mpeg is encoded with the 16/9 flag and the DVD adjusts the picture acordingly....

The Ghostbusters movie for instance is 1024*768....

Flaskmpeg on thge other hand messes everything upp by always thinking that a dvd can only be 720*576 max....

[zeb7]

If the Ghostbusters DVD that you're talking about is 1024*768 then its the first HD-DVD on the market before HD-DVD has been launched.

[AlgoRhythm]

Actually Technoid is accurate with his comment about 1024x768...

An anamorphic DVD uses the full resolution of the DVD, and doesn't encode any black bars at the top and bottom.

IOW, if you watch an anamorphic DVD on a 4:3 set without it scaling it properly, it would look vertically stretched and fill the whole screen instead of being in letterbox format.

An anamorphic DVD at 720x576 intended for 16:9 playback would have to be displayed on a 1024x768 (on a 4:3 set, that is) screen to display full resolution at the proper aspect ratio.

And here's why:
The 576 pixels of vertical resolution are intended to fit in 3/4 of the screen (with the blank space in the remaining 1/8s at the top and bottom.), to be 16:9. So, if 576 is 3/4 of the screen vertically, 768 would be the appropriate height of the screen. Since it's 4:3, it would be 1024x768. (Yes, it would be upscaled horizontally...)

Of course, all of this assumes that you're watching it on a screen capable of it. (Like a computer monitor) I never watch DVDs on anything less.


AlgoRhythm

[dZeus]

Originally posted by AlgoRhythm
Actually Technoid is accurate with his comment about 1024x768...

An anamorphic DVD uses the full resolution of the DVD, and doesn't encode any black bars at the top and bottom.

IOW, if you watch an anamorphic DVD on a 4:3 set without it scaling it properly, it would look vertically stretched and fill the whole screen instead of being in letterbox format.

An anamorphic DVD at 720x576 intended for 16:9 playback would have to be displayed on a 1024x768 (on a 4:3 set, that is) screen to display full resolution at the proper aspect ratio.

And here's why:
The 576 pixels of vertical resolution are intended to fit in 3/4 of the screen (with the blank space in the remaining 1/8s at the top and bottom.), to be 16:9. So, if 576 is 3/4 of the screen vertically, 768 would be the appropriate height of the screen. Since it's 4:3, it would be 1024x768. (Yes, it would be upscaled horizontally...)

Of course, all of this assumes that you're watching it on a screen capable of it. (Like a computer monitor) I never watch DVDs on anything less.
AlgoRhythm

That's not true. You want to scale the source as little as possible, and there's no need at all to scale it vertically. You won't have to make the window have a 16:9 aspect ratio, which results into a 1024x576 resolution, in stead of a 768x576 (used to display 4:3 DVD PAL content on a computer monitor without scaling).

On a 4:3 TV set the anomorphic image will be scaled down vertically to 432 lines in stead of 576, and then the remaining lines will be filled up with black bars (both top and bottom). Right now I would guess that Technoid is confused with the 1024x576 window that the software dvd player uses to display the anomorphic contents of the DVD... unless he proves me wrong

[Technoid]

Actualy I Demuxed the MP2 stream from the vob file and when I analyzed it I was somewhat confused to find it 1024*576 instead of the obviouse 720*576.

I do admit that I confused my Screen rezolution (1024*768) with the rezolution of the dvd file (1024*576).

But I have re "ripped" the mpg stream and confirmed the 1024*576 rezolution.

should i post a second or two ?

[AlgoRhythm]

dZeus,

I never said it would need to be scaled vertically. That was my whole point. If you use 1024x768, there is no reason to scale it vertically. However it _WILL_ be scaled horizontally, if you want to see the full vertical resolution. That's the whole point of anamorphic DVDs.

Of course if you have one of those cool Sony sets (Wega, is it?), it will actually use all the scan lines within 3/4 of the vertical scanning area of the set.


AlgoRhythm

[dZeus]

well, I re-read what you said in your first post, and I stand corrected... you're right. I got confused because I though we were talking about TV sets and playing it back windowed on the monitor. Of course, if you watch it on your monitor, you watch it fullscreen, and if you do, 1024x768 is indeed the most appropriate resolution for Anomorphic widescreen PAL DVDs since you indeed don't have to scale vertically if you do.

Though in fact this is absolutely the same as watching the stream in 1024x576 and adding black to top and bottom..

Fact remains that the videostream still is 720x576, and not 1024x768 (which made me misinterpreted your post... sorry )

[Flying dutchman]

Er, where the heck does the number 768 come from?
If you want to view a PAL image on a computer monitor with square pixels a 768-pixel _horizontal_ resolution would be appropriate, but it is entirely artificial. TV pixels aren't square...

As a matter of fact, PAL uses a line frequency of 15625 Hz, making up 25 frames/sec of 625 scanlines each (25*625=15625). Of these 625 scanlines only 576 are potentially visible (depending on the calibration of the TV), the rest is used for stuff like videotext.

[dZeus]

here we go again

And here's why:
The 576 pixels of vertical resolution are intended to fit in 3/4 of the screen (with the blank space in the remaining 1/8s at the top and bottom.), to be 16:9. So, if 576 is 3/4 of the screen vertically, 768 would be the appropriate height of the screen. Since it's 4:3, it would be 1024x768. (Yes, it would be upscaled horizontally...

so what he's saying (and he's correct) is that the decoded image with proper aspect ratio for anomorphic PAL DVDs is 1024x576, but if you convert that to a 4:3 resolution (as you watch it on a 4:3 computer monitor), you'll get 1024x768 if you don't want to scale the image vertically