Really confused about resolutions....

[sam9s]

I am really confused about few things here please guide me on this....


1. What is the native resolution of a DVD......
2. What do we mean by TV resolution then....
3. Whats the difference between DVD resolution and a TV resolution.
4. If a dvd is suppose to play at its native resp (what ever it is) how does a
latest DVD played upscales it it say 1080p. What I am unable to understand is if a
DVD is suppose to play at say x resoulution what does the player do to upscale it, is it tecnically possible and does it make a difference. I do not have DVD player that upscales a DVD but I am planning to get one if its really is worth.
Also I dont understand one thing.......when I play my Matrix Reloaded DVD on my philips DVP5500 player my TV (Philips HD CRT@720p) playes it at 576p through component in. but when I play my x-Men II DVD it playes at 480p, what does this mean......why was x-men not played at 576p

I am really confused about this resolution business.....

[lordsmurf]

1. DVDs have several valid resolutions available. Most commercially-pressed discs use 720x480 NTSC (720x576 PAL), because they are from studio-quality source. Many home uses opt for 352x480 NTSC (352x576 PAL), because it's an excellent choice, allowing for 3-4 hours of good quality on a single DVD5. 704x480 and 352x240 are also valid.

2. TV has no resolution. There are digital equiv values, however, but they are dependent on the exact source (antenna, VHS, S-VHS, DV, cable, digital cable, satellite, etc).

3. Not a valid question. See previous.

4. The upscaling is basically fake. You add extra pixels of like color side-by-side. It simply makes it appear a little less soft when viewed on a mega-sized 50-60" plus screen. 480p is a standard movie DVD (23.976 fps, progressive, 720x480 Full D1, NTSC). The 576p is PAL.

More on resolutions:
http://digitalfaq.com/dvdguides/capture/understandsource.htm#analogsource

[davideck]

Since this is in the HDTV forum, I assume by "TV Resolution" you mean the native resolution of the display. There are several popular screen resolutions;

1024x768
1366x768
1280x720
1920x1080

etc.

For an analog input, the HDTV can digitize at a resolution suitable to optimize its own display. Some sets are really good at this. DVD Analog Component looks fantastic!

For a digital input, the HDTV needs to "interpolate" from the input resolution (DVD = 720x480) to the display resolution. This does not provide any extra detail and it is not a perfect process so it's usually best to interpolate only once.

If you interpolate (upscale) in the DVD player to 720p (1280x720) and your display is 1024x768, then the HDTV will have to re-interpolate the upscaled image. Why bother?

I do find that a resolution of 480p over HDMI can provide a slight advantage; the DVD player provides a digital progressive source in its native resolution and the HDTV provides the interpolation. YMMV.

It has also been my experience that capturing at 352 (Half_D1) for display on an HDTV will look softer compared to a 720 capture for almost any source.

[sam9s]

mmm some clearification here......thanks for the link lord..
David sorry for being such a noob but if I am not wrong the number 720x480 specify, the number of lines (horizontalxvertical) the display contains and so if the DVD's native res is 720x480 it means the DVD contains 720 horizontal and 480 verticle lines of information.(I am still not sure what PAL 576 means)
Now coming to the TV, my TV is capable of displaying 720p which means it can display a max of 1280x720. So here lies the confusion, if the TV diaplay is 1280x720 and DVD is 720x480, the TV would fit less number of lines to its display (having more lines) and this should actually detoriate the display............I know I might be making no sence here, but I need some of my basics clear...
Also if DVD native resolution is 720x480, why is the market flooded with HD TVs with 1080p (1920x1080), when HD-DVD/Blue ray are no where even near to be seen in the conventional market, and DVD offer much less. Upscaling part I suppose is a gimmick or a marketing stratagy to get the new bread of DVD playes selling.

[guns1inger]

DVD encoded for NTSC playback has 480 horizontal lines, 720 pixels wide. PAL has 576 lines, 720 pixels wide. Your 720p TV will upscale the 480 lies to fit the screen.

HD DVD or BluRay are encoded at 1920 pixels wide by 1080 lines, hence the push for HD TVs to support the full resolution.

[jagabo]

HD DVD or BluRay are encoded at 1920 pixels wide by 1080 lines, hence the push for HD TVs to support the full resolution.

And don't forget there's HD broadcast, cable, satellite, camcoders, video games, etc.

if the TV diaplay is 1280x720 and DVD is 720x480, the TV would fit less number of lines to its display (having more lines) and this should actually detoriate the display...

How else would you propose viewing the 720x480 image on your 1280x720 TV? In a 720x480 box in the middle of the screen? That would be sharper but the aspect ratio would be wrong and everybody else in the world would complain that their screen isn't filled.

[edDV]

mmm some clearification here......thanks for the link lord..
David sorry for being such a noob but if I am not wrong the number 720x480 specify, the number of lines (horizontalxvertical) the display contains and so if the DVD's native res is 720x480 it means the DVD contains 720 horizontal and 480 verticle lines of information.(I am still not sure what PAL 576 means)
Now coming to the TV, my TV is capable of displaying 720p which means it can display a max of 1280x720. So here lies the confusion, if the TV diaplay is 1280x720 and DVD is 720x480, the TV would fit less number of lines to its display (having more lines) and this should actually detoriate the display............I know I might be making no sence here, but I need some of my basics clear...
Also if DVD native resolution is 720x480, why is the market flooded with HD TVs with 1080p (1920x1080), when HD-DVD/Blue ray are no where even near to be seen in the conventional market, and DVD offer much less. Upscaling part I suppose is a gimmick or a marketing stratagy to get the new bread of DVD playes selling.

I think we need to better describe your TV. How do you know that your CRT HDTV is 1280x720p?

Most CRT HD sets can handle 1080i (540 lines per field), 480p and 576p. Some can scan 720p or 720 lines in one scan.

For a CRT, these "scan lines" are painted to the back of the CRT tube. The resolution you see from the front is often far less due to limitations of dot pitch and shadow mask density. A typical consumer HD CRT will resolve ~800x600, some better models may reach ~1024x768. The highest end models may reach 1440x1080. A Philips direct view tube would be at the lower end of that scale.

As said above, a DVD is encoded either 720x480 or 720x576. Your TV should be able to display either natively as 480p or 576p progressive and your tube should be capable of resolving all the pixels. That should be the ideal display method for a progressive movie. Analog component connections at 480/576p 59.94 or 50 frames per second will be essentially displayed directly. All is good.

If you were to use an upscaling progressive DVD player, the player would resample the 720x480/576 raster to 1280x720p. If your set is able to receive and scan 720p, the all 720 lines will be scanned to the back of your CRT. They may not all be visible from the front of the CRT as limited by the number of dots on your display. Most likely, you will see little or no improvement.

If you were to connect your DVD player as 480i or 576i to the TV, the TV would "upscale" vertical scan to 960-1080 interlace lines (480-540 per field) and scan twice for odd and even lines behind the tube. If the DVD was NTSC, this would degrade the picture unless the TV included cinema inverse telecine circuits to restore progressive frames. In most cases, 1080i upscale would produce a lower quality picture from a progressive movie.

This analysis would differ if the TV was a fixed pixel display such as a plasma or LCD. In those cases, a DVD playback is always upscaled to the fixed display resolution (~1024 to 1366x768 typ). The upscale usually takes place in the internal HDTV scaler.