"Enhanced for 16:9 TV" DVDs
 

I notice some DVDs say this and I can see that it's better filling the 16:9
screen but not sure how it's doing it. Is this a standard that means the
same on all dvds ?

I was watching Pirates of the Caribbean last night. The initial screen
looked like most 2:35 to 1 pictures do - real skinny horizontally - even on
a 16:9 tv; the movie menu was sort of full screen and then when movie
started it went to an appropriate 16:9 aspect that almost filled the screen
and had small horizontal black bars top & bottom. The picture looked pretty
good and I didn't notice any signs of stretching. I assume it must be
zoomed and / or clipped somewhere.

I'm not complaining, just trying to understand the procedure and if it
means the same thing on all dvds.

Walt

"Walt Mather" wrote in message
...
I notice some DVDs say this and I can see that it's better filling the
16:9
screen but not sure how it's doing it. Is this a standard that means the
same on all dvds ?

Sort of a standard, you will also see it referred to as Anamorphic, Enhanced
for widescreens, Widescreen Version, etc.. It means the full 480 lines are
used and the picture is squeezed horizontally to fit in the 4:3 format,
instead of using a letterbox format with only 320 or so lines. If you have a
progressive DVD player, this is as good as it gets on DVD as you will be
able to see 480p. If you view it on a 4:3 TV, you will either see the
squeezed picture or you will tell your DVD player that you have a 4:3 TV and
it will convert it to letter box for you, throwing away 1/3 of the lines.


I was watching Pirates of the Caribbean last night. The initial screen
looked like most 2:35 to 1 pictures do - real skinny horizontally - even
on
a 16:9 tv; the movie menu was sort of full screen and then when movie
started it went to an appropriate 16:9 aspect that almost filled the
screen
and had small horizontal black bars top & bottom. The picture looked
pretty
good and I didn't notice any signs of stretching. I assume it must be
zoomed and / or clipped somewhere.

To remain true to the cinematic aspect ratio, you will see some black bars
for anything greater than 1.78:1 (16:9). If they fill the screen some
stretching and/or clipping would be needed if the movie was produced at
2:35:1.


Brad Houser

"Walt Mather" wrote in message
...
I notice some DVDs say this and I can see that it's better filling the
16:9
screen but not sure how it's doing it. Is this a standard that means the
same on all dvds ?

I was watching Pirates of the Caribbean last night. The initial screen
looked like most 2:35 to 1 pictures do - real skinny horizontally - even
on
a 16:9 tv; the movie menu was sort of full screen and then when movie
started it went to an appropriate 16:9 aspect that almost filled the
screen
and had small horizontal black bars top & bottom. The picture looked
pretty
good and I didn't notice any signs of stretching. I assume it must be
zoomed and / or clipped somewhere.

I'm not complaining, just trying to understand the procedure and if it
means the same thing on all dvds.

A normal DVD is designed for a 4:3 display. It is either cropped (pan and
scan) to get 4:3, or it is letterboxed. If it is letterboxed, then out of
its 480 vertical resolution, some lines are simply filled with black. Thus
for a 2.35:1 movie, only about 272 lines are used to encode the actual image
of the movie. For a 1.85:1 film, it uses about 346 lines. The lines above
and below this are wasted. They are stored on the DVD and displayed on the
TV, but all they contain is black.

An "enhanced for 16:9" anamorphic DVD is designed for a 16:9 aspect ratio.
That is, it uses the same 480 pixels high (and same 720 samples across each
line) as a regular DVD (necessary to be playable in a normal DVD player) but
assumes the width will be 1.78 times its height, rather than 1.33 times. The
way they actually do it is squeeze the image when it is recorded onto the
DVD, so that if it were shown on a 4:3 display everything would look too
tall and narrow.

This is the same process as used to make "anamorphic" 2.35:1 movies - if you
look at the original piece of film, the image is much narrower than 2.35:1
and looks squeezed. The original camera lens squeezes the image to make it
narrower on film than in real life, and the lens in the projector widens the
image to its final aspect ratio when projected. In the case of anamorphic
DVDs, it's done electronically via a linear 4:3 to 16:9 stretch mode (either
in the DVD player or in your TV).

16:9 (1.78:1) is of course still not as wide as either 1.85:1 or 2.35:1, so
there are still some wasted black bars at the top and bottom, but they are
smaller. For a 1.85:1 movie, a 16:9 anamorphic DVD will use about 461 lines
for actual picture content, so only very few are wasted, and for a 2.35:1
movie, about 363 lines. (But if you have a CRT display, it may appear to
waste even fewer lines since your set may overscan most or all of the wasted
black lines off the screen. Of course, this means you're missing some
picture information to the sides as well...)

Some owners of 4:3 TVs can also benefit from (and properly show) 16:9
anamorphic DVDs: if your TV has a "16:9 compression mode", or whatever it
may be called, it can adjust the electron beam so that it draws the 480
scanlines in a shorter (compressed) vertical distance. This gives you a 16:9
picture region on your 4:3 set that can still display the full 480 lines of
vertical resolution. Of course if you have a 4:3 HDTV, you can also view
16:9 DVDs at their full vertical resolution.

Thanks Brad and Matthew for great explanations. I understand it a whole lot
better now.
Walt


"Matthew Vaughan" wrote in message
...
"Walt Mather" wrote in message
...
I notice some DVDs say this and I can see that it's better filling the
16:9
screen but not sure how it's doing it. Is this a standard that means
the
same on all dvds ?

I was watching Pirates of the Caribbean last night. The initial screen
looked like most 2:35 to 1 pictures do - real skinny horizontally - even
on
a 16:9 tv; the movie menu was sort of full screen and then when movie
started it went to an appropriate 16:9 aspect that almost filled the
screen
and had small horizontal black bars top & bottom. The picture looked
pretty
good and I didn't notice any signs of stretching. I assume it must be
zoomed and / or clipped somewhere.

I'm not complaining, just trying to understand the procedure and if it
means the same thing on all dvds.

A normal DVD is designed for a 4:3 display. It is either cropped (pan and
scan) to get 4:3, or it is letterboxed. If it is letterboxed, then out of
its 480 vertical resolution, some lines are simply filled with black. Thus
for a 2.35:1 movie, only about 272 lines are used to encode the actual
image
of the movie. For a 1.85:1 film, it uses about 346 lines. The lines above
and below this are wasted. They are stored on the DVD and displayed on the
TV, but all they contain is black.

An "enhanced for 16:9" anamorphic DVD is designed for a 16:9 aspect ratio.
That is, it uses the same 480 pixels high (and same 720 samples across
each
line) as a regular DVD (necessary to be playable in a normal DVD player)
but
assumes the width will be 1.78 times its height, rather than 1.33 times.
The
way they actually do it is squeeze the image when it is recorded onto the
DVD, so that if it were shown on a 4:3 display everything would look too
tall and narrow.

This is the same process as used to make "anamorphic" 2.35:1 movies - if
you
look at the original piece of film, the image is much narrower than 2.35:1
and looks squeezed. The original camera lens squeezes the image to make it
narrower on film than in real life, and the lens in the projector widens
the
image to its final aspect ratio when projected. In the case of anamorphic
DVDs, it's done electronically via a linear 4:3 to 16:9 stretch mode
(either
in the DVD player or in your TV).

16:9 (1.78:1) is of course still not as wide as either 1.85:1 or 2.35:1,
so
there are still some wasted black bars at the top and bottom, but they are
smaller. For a 1.85:1 movie, a 16:9 anamorphic DVD will use about 461
lines
for actual picture content, so only very few are wasted, and for a 2.35:1
movie, about 363 lines. (But if you have a CRT display, it may appear to
waste even fewer lines since your set may overscan most or all of the
wasted
black lines off the screen. Of course, this means you're missing some
picture information to the sides as well...)

Some owners of 4:3 TVs can also benefit from (and properly show) 16:9
anamorphic DVDs: if your TV has a "16:9 compression mode", or whatever it
may be called, it can adjust the electron beam so that it draws the 480
scanlines in a shorter (compressed) vertical distance. This gives you a
16:9
picture region on your 4:3 set that can still display the full 480 lines
of
vertical resolution. Of course if you have a 4:3 HDTV, you can also view
16:9 DVDs at their full vertical resolution.

"Walt Mather" wrote in message
...

: I notice some DVDs say this and I can see that it's better filling the
16:9
: screen but not sure how it's doing it. Is this a standard that means
the
: same on all dvds ?

====================
It does NOT mean that it filles a 16:9 screen.
It merely means it has more resolution on a 16:9 screen.

Anamorphic Enhancement for 16:9 TVs has NOTHING to do with changing the
aspect ratio.
=======================
:
: I was watching Pirates of the Caribbean last night. The initial
screen
: looked like most 2:35 to 1 pictures do - real skinny horizontally -
even on
: a 16:9 tv; the movie menu was sort of full screen and then when movie
: started it went to an appropriate 16:9 aspect that almost filled the
screen
: and had small horizontal black bars top & bottom. The picture looked
pretty
: good and I didn't notice any signs of stretching. I assume it must be
: zoomed and / or clipped somewhere.
:
: I'm not complaining, just trying to understand the procedure and if
it
: means the same thing on all dvds.
:
: Walt
:
:

On Tue, 02 Mar 2004 17:59:08 GMT, "Matthew Vaughan"
wrote:


An "enhanced for 16:9" anamorphic DVD is designed for a 16:9 aspect ratio.
That is, it uses the same 480 pixels high (and same 720 samples across each
line) as a regular DVD (necessary to be playable in a normal DVD player) but
assumes the width will be 1.78 times its height, rather than 1.33 times.


Just curious

Echostar and Bell express-vu use 480x480 4:2:0 format for transmitting
broadcast mpeg dvb destined for a 4x3 screen

I've heard that each pixel is "4x3 rectangular " and the mpeg decoder
recognizes this format

is this related to anamorphic compression, or is this another
technique?

wrote in message
...
On Tue, 02 Mar 2004 17:59:08 GMT, "Matthew Vaughan"
wrote:

An "enhanced for 16:9" anamorphic DVD is designed for a 16:9 aspect
ratio.
That is, it uses the same 480 pixels high (and same 720 samples across
each
line) as a regular DVD (necessary to be playable in a normal DVD player)
but
assumes the width will be 1.78 times its height, rather than 1.33 times.


Just curious

Echostar and Bell express-vu use 480x480 4:2:0 format for transmitting
broadcast mpeg dvb destined for a 4x3 screen

I've heard that each pixel is "4x3 rectangular " and the mpeg decoder
recognizes this format

is this related to anamorphic compression, or is this another
technique?

It's all basically the same idea. Normal DVD is 480x720, which means that
those "pixels" aren't square, either (would need to be 480x640). The data
storage/transmission format doesn't need to assume square pixels, it's just
a way of storing data in a virtual grid. That data is then "projected"
however necessary for display. Yes, if you were to read that data and assume
the pixels were square, none of these formats would come out looking right.
Some would be stretched, some squeezed, but none would result in the correct
aspect ratio or proportions.

wrote

Echostar and Bell express-vu use 480x480 4:2:0 format for transmitting
broadcast mpeg dvb destined for a 4x3 screen

No, they use 544 x 480. Even more oddball, I guess, but still
non-square pixels.

On Thu, 04 Mar 2004 06:11:53 GMT, Karyudo
wrote:

wrote

Echostar and Bell express-vu use 480x480 4:2:0 format for transmitting
broadcast mpeg dvb destined for a 4x3 screen

No, they use 544 x 480. Even more oddball, I guess, but still
non-square pixels.

No they do not

see MPEG-2 Sample Shots in http://www.coolstf.com/mpeg/index.html#ts

"Dish Network uses 480x480 resolution"

On Fri, 05 Mar 2004 12:08:02 -0500, wrote:

On Thu, 04 Mar 2004 06:11:53 GMT, Karyudo
wrote:

wrote

Echostar and Bell express-vu use 480x480 4:2:0 format for transmitting
broadcast mpeg dvb destined for a 4x3 screen

No, they use 544 x 480. Even more oddball, I guess, but still
non-square pixels.

No they do not

see MPEG-2 Sample Shots in http://www.coolstf.com/mpeg/index.html#ts

"Dish Network uses 480x480 resolution"


Hmm... interesting. But I have actually captured some Dish stuff via
DVB recently, and it's 544 x 480. So either we're both right (we could
both be missing some key point), or your information is outdated.