When does HDTV stop being HD

On Nov 29, 8:16 am, NadCixelsyd wrote:

Is the pixel count and aspect ration embedded in the DVD data? Could
a DVD be 720P if it weren't for a capacity problem in which a movie
took up 4 DVD's? Does a DVD do some form of data compression or is it
raw output (like an audio CD)?

I've been told tDVDs are compressed, unlike laserdisc, which was the
original disappointment of an otaku I knew.

On Nov 29, 5:16 am, NadCixelsyd wrote:
On Nov 27, 1:50 am, Kimba W Lion kimbawlion wrote:

NadCixelsyd wrote:
Most DVD's sold in the past 8 years are 960x540 pixels.

DVDs are 720x480 or 720x576.

960x540 is what you get from one of the hi-def discs if you don't
meet the
copy protection requirements.

My statement was based on an experiment that I did (which may have
been flawed) and some assumptions that I made(which may have been
wrong).

My 5-year old PC plays DVD's and has a snapshot feature in which
one
can capture one frame of the film in a Jpeg file. So I took about
20
DVD's, some old, some new, and took a frame from each film. All of
the JPG files generated were either 720 or 960 pixels wide. It
appeared that the older DVD's were 720 pixels, but I could not find
any definitive pattern. The pixel height was anywhere from 305 to
540
depending on the aspect ratio of the film.

Is the pixel count and aspect ration embedded in the DVD data?
Could
a DVD be 720P if it weren't for a capacity problem in which a movie
took up 4 DVD's? Does a DVD do some form of data compression or is
it
raw output (like an audio CD)?

Your PC converts what it gets

DVDs are either down converted from an HD master or were taken
directly an SD digital tape machine most often a Digital Betacam. the
active pixel count is 720x483 based in a 525 line system. Europe uses
a 625 line system. These can become NTSC or PAL when the components
are run through an encoder but that is not used for DVD. Video is
MPEG2.

Laserdisc was an analog composite FM recording. I believe the carrier
frequencies for NTSC Laser were the same PAL SMPTE C broadcast 1"
videotape. Audio initially was 2 FM carriers but later discs added
digital audio (I think. Its been a LONG time).

GG

In article NadCixelsyd writes:


My statement was based on an experiment that I did (which may have
been flawed) and some assumptions that I made(which may have been
wrong).

My 5-year old PC plays DVD's and has a snapshot feature in which one
can capture one frame of the film in a Jpeg file. So I took about 20
DVD's, some old, some new, and took a frame from each film. All of
the JPG files generated were either 720 or 960 pixels wide.

Because they were 720 x 480. Some of them were widescreen, which told
the display to stretch them by 4/3 to get 960 pixels width.

It
appeared that the older DVD's were 720 pixels, but I could not find
any definitive pattern. The pixel height was anywhere from 305 to 540
depending on the aspect ratio of the film.

Is the pixel count and aspect ration embedded in the DVD data? Could
a DVD be 720P if it weren't for a capacity problem in which a movie
took up 4 DVD's? Does a DVD do some form of data compression or is it
raw output (like an audio CD)?

A DVD could not be 720p. It is not one of the allowed resolutions.

See: http://www.dvddemystified.com/dvdfaq.html#3.4


Alan