Questions about DVD-movie format

[Flux]

DVD-movies vertical resolution is 576 pixels for PAL and 480 pixels for NTSC

But what about horizontal resolution when stretching or zooming to common 16:9 TVs? Does resolution differ if HTPC does the stretching instead TV? I mean target resolution because source resolution is always 720 pixels. Some say it's 1024 (missing pixels are interpolated) for PAL but some say it's still 720.

Why anamorphic DVD-movies larger than 16:9 aspect ratio have been also letterboxed? For example 2.35:1 anamorphic movie in PAL case has only 435 vertical pixels for image and rest are black.

[The Geek]

But what about horizontal resolution when stretching or zooming to common 16:9 TVs? Does resolution differ if HTPC does the stretching instead TV? I mean target resolution because source resolution is always 720 pixels. Some say it's 1024 (missing pixels are interpolated) for PAL but some say it's still 720.

The TV always stretches the image horizontally. The pixels are just wider than they are high.
On LCD/Plasma TVs, which have square pixels, it will be interpolated (like 1024x576 for 16:9).

Why anamorphic DVD-movies larger than 16:9 aspect ratio have been also letterboxed? For example 2.35:1 anamorphic movie in PAL case has only 435 vertical pixels for image and rest are black.

Because only 4:3 and 16:9 is defined for TV. So, Cinemascope is letterboxed within the 16:9 frame.
To be precise, even 1.85:1 movies are letterboxed in that 16:9 frame, as 16:9 doesn't exist in theaters. The 1.85:1 is a bit wider than 16:9, and has tiny black bars at the top and bottom of the 16:9 image.

The Geek

[Mug Funky]

the horizontal resolution (at least for CRT TVs) is meaningless. on a DVD it's either 720, 704 or 352 pixels, but this says nothing of aspect ratio.

if you're thinking square pixels, then you figure it out from vertical resolution * AR, so for PAL 4:3, you get 576*(4/3) = 768, and for NTSC you get 640.

what comes out of a HTPC really depends on the setup - it could just be outputting 720, or it could be outputting something else. with a CRT television there's not going to be much gain above 720 unless you have an extremely good TV (not even the special-for-monitoring ones show much difference).

[movmasty]

Originally posted by Mug Funky
the horizontal resolution (at least for CRT TVs) is meaningless. on a DVD it's either 720, 704 or 352 pixels, but this says nothing of aspect ratio.

if you're thinking square pixels, then you figure it out from vertical resolution * AR, so for PAL 4:3, you get 576*(4/3) = 768, and for NTSC you get 640.

what comes out of a HTPC really depends on the setup - it could just be outputting 720, or it could be outputting something else. with a CRT television there's not going to be much gain above 720 unless you have an extremely good TV (not even the special-for-monitoring ones show much difference).
Not exactly, there is not a resolution but there is a bandwidth,

thus you can say that BOTH NTSC and PAL have something similar to 640 pixels of horizontal resolution, but very hard to find tv sets that really carry 640 dots(that with 3 colours will be 1920).

Maybe hq widescreen tv sets have 704 dots on the screen, but quality will increase very slightly over 640.

[zilog jones]

But what about when using RGB signals on a CRT TV, and not PAL or NTSC?

[movmasty]

Originally posted by zilog jones
But what about when using RGB signals on a CRT TV, and not PAL or NTSC?
tv out converts rgb to pal or ntsc

[mpucoder]

Whether it's component (RGB, RGBS, RGBHV, or YPrPb), Y/C (S-video), composite, or digital (SDI or PDI) it is still either PAL or NTSC. These standards define the timing and resolution. (SDTV - of course HDTV is different, but can be conveyed in all the above forms)