CBS Hi Def football problems

On CBS Hi def football games there is usally pixelation when the camera
moves rapidly and often with rapid subject movement. This does not occur
with other CBS hi def broadcasts and is not seen on any other broadcaster's
hi def football transmission, for example ESPN. Is this something peculiar
to CBS or the local affiliate that rebroadcasts the signal? Changing
resolution in the receiver, 720 or 1080, makes no difference. Unfortunatley
the local dork broadcasters for ABC and FOX do not rebroadcast the hi-def
signal or allow satellite reception.

"bmoag" wrote in message
. com...
: On CBS Hi def football games there is usally pixelation when the
camera
: moves rapidly and often with rapid subject movement. This does not
occur
: with other CBS hi def broadcasts and is not seen on any other
broadcaster's
: hi def football transmission, for example ESPN. Is this something
peculiar
: to CBS or the local affiliate that rebroadcasts the signal? Changing
: resolution in the receiver, 720 or 1080, makes no difference.
Unfortunatley
: the local dork broadcasters for ABC and FOX do not rebroadcast the
hi-def
: signal or allow satellite reception.
:
:
:
I know that Fox, ABC and ESPN all use 720p while CBS and NBC use
1080i. That might be the difference, although here in DFW ( I don't
know where you are) I can't tell any difference, using my OTA STB,
between the two. Any artifiacts that I see, I assume are "comming
down the pike" because it's live, not recorded.

More than likely your TV...especially if lcd/plasma. They do not handle
rapid motion well.
And your tv will only display one hd format...regardless of what you select
at the receiver.

"bmoag" wrote in message
. com...
On CBS Hi def football games there is usally pixelation when the camera
moves rapidly and often with rapid subject movement. This does not occur
with other CBS hi def broadcasts and is not seen on any other
broadcaster's hi def football transmission, for example ESPN. Is this
something peculiar to CBS or the local affiliate that rebroadcasts the
signal? Changing resolution in the receiver, 720 or 1080, makes no
difference. Unfortunatley the local dork broadcasters for ABC and FOX do
not rebroadcast the hi-def signal or allow satellite reception.

"bmoag" wrote in message .com...

On CBS Hi def football games there is usally pixelation when the camera
moves rapidly and often with rapid subject movement. This does not occur
with other CBS hi def broadcasts and is not seen on any other broadcaster's
hi def football transmission, for example ESPN. Is this something peculiar
to CBS or the local affiliate that rebroadcasts the signal? Changing
resolution in the receiver, 720 or 1080, makes no difference. Unfortunatley
the local dork broadcasters for ABC and FOX do not rebroadcast the hi-def
signal or allow satellite reception.

As I understand it, there are two possible sources for pixelization.
One is when the broadcaster does a poor job of MPEG2 compression.
What I've noticed is that the problem is very common in live
broadcasts such as sports, and much rarer when showing film-like
sources such as prime time dramas. When they rely on automatic
conversion in real time, you don't get the quality that is possible if
something is prepared in advance.

The other possible source is when the network sends a good feed but
the local station is enamored of multicasting, and has to convert the
image to a slower bit rate.

In article ,
(Paul Kienitz) writes:
"bmoag" wrote in message .com...

On CBS Hi def football games there is usally pixelation when the camera
moves rapidly and often with rapid subject movement. This does not occur
with other CBS hi def broadcasts and is not seen on any other broadcaster's
hi def football transmission, for example ESPN. Is this something peculiar
to CBS or the local affiliate that rebroadcasts the signal? Changing
resolution in the receiver, 720 or 1080, makes no difference. Unfortunatley
the local dork broadcasters for ABC and FOX do not rebroadcast the hi-def
signal or allow satellite reception.

As I understand it, there are two possible sources for pixelization.
One is when the broadcaster does a poor job of MPEG2 compression.
What I've noticed is that the problem is very common in live
broadcasts such as sports, and much rarer when showing film-like
sources such as prime time dramas. When they rely on automatic
conversion in real time, you don't get the quality that is possible if
something is prepared in advance.

MPEG2 encoding for film does so with a 24fps source, and there is ALOT
of redundancy when converting to 60i. This allows for significantly
more apparent compression than with a real live scene, which would have
effectively full 60i temporal detail. Of course, true 24fps MPEG
encoding instead of 60i encoding of 24fps would be better, but full
60i encoding (e.g. for live sports) is significantly more challenging.
There is actually MORE TEMPORAL detail in a live 60i broadcast than
for 24fps film material (many fields are low overhead repeats.)

So, live encoding is closer to the 'edge' for pixelization or other
gross scale MPEG compression artifacts than 24fps.

There is also the opportunity for non-realtime compression for film
material, but I suspect that the innate redundancy of film material
is the biggest difference. I doubt that offline compression is done
very often for movies anyway. (AFAIK, CBS doesn't really do a full
ATSC encode for its stations, and that is done at the TV station
itself. SO, there isn't really an opportunity for non-realtime
ATSC encoding.)

John

It's either your set or your local station or cable provider. CBS
football games in LA are amazingly clear.

Bill

"bmoag" wrote in message
. com...
On CBS Hi def football games there is usally pixelation when the camera
moves rapidly and often with rapid subject movement. This does not occur
with other CBS hi def broadcasts and is not seen on any other
broadcaster's
hi def football transmission, for example ESPN. Is this something
peculiar
to CBS or the local affiliate that rebroadcasts the signal? Changing
resolution in the receiver, 720 or 1080, makes no difference.
Unfortunatley
the local dork broadcasters for ABC and FOX do not rebroadcast the
hi-def
signal or allow satellite reception.

And your tv will only display one hd format...regardless of what you select
at the receiver.
--------
Not true. Many TVs display 480p/720p/1089i without conversion.

(John S. Dyson) wrote in message ...

There is also the opportunity for non-realtime compression for film
material, but I suspect that the innate redundancy of film material
is the biggest difference.

You're probably right.

Abe wrote:
And your tv will only display one hd format...regardless of what you select
at the receiver.

--------
Not true. Many TVs display 480p/720p/1089i without conversion.


Care to cite some examples?

Matthew

--
Thermodynamics and/or Golf for dummies: There is a game
You can't win
You can't break even
You can't get out of the game

"Matthew L. Martin" wrote in message ...
Abe wrote:
And your tv will only display one hd format...regardless of what you select
at the receiver.

--------
Not true. Many TVs display 480p/720p/1089i without conversion.


Care to cite some examples?


Princeton AF3.0HD.


MH.