Marantz HD6400W Manual Do Utilizador

While they may dif-

fer on the choice

of digital formats

(1080i, 720p, 480i,

etc.) the netw orks

broadcast plans

center mainly on

select primetime *

program viewing.

Because of the

production tech-

niques and equip-

ment upgrades

necessary for digi-

tal broadcasts the

telecasting of

sports or other

live  events will not

become available

until audience view -

ership can justify

costs.

Some initial net-

w ork plans for digi-

tal broadcasts:   

ABC- Wonderful

W orld of Disney  (in

720p format); to

phase in other

HDTV broadcasts

later.

CBS- proposed to

send five hours of

1080i programming

per week 

NBC- to begin

shooting The

Tonight Show with

Jay Leno  in HDTV

beginning in 1999;

also plans to show

other primetime

show s in HDTV 

Fox to distribute

some portion of its

schedule in 720p

HDTV.

 

 

*Outside of the

primetime slot for

netw ork digital

show s local sta-

tions can provide

different program-

ming on their digital

broadcast channel.

They are free to

convert current

NTSC programming

into digital SDTV or

even upgrade their

signal to true HDTV.

ABC, NBC and Fox

are advising affili-

ates to use 480p

for the majority of

its broadcast day,

while CBS recom-

mends its stations

use the 480i for-

mat.     

digital

1

nf

0

rmation

is approxi-

mately twice the vertical and horizontal resolu-
tion of today’s NTSC TV. Because of the extra 
width (16:9) format of HDTV the picture con-
tains about five times as much information (or 
pixels) as conventional TV. 
HDTV also includes 5.1 channels of Dolby 
Digital surround sound to be broadcast through 
two front speakers; one center speaker; two rear 
back speakers; and a separate bass channel or 
subwoofer signal.

• HDTV refers to the product/system with the fol-

lowing minimum performance specs:
- Resolution: vertical display resolution of 

720P, 1080I, or higher

- Aspect Ratio: capable of displaying 16:9 for-

mat images at the minimum resolution levels

- Audio: receives, reproduces, and/or outputs 

Dolby digital audio

- Receiver: receives all ATSC (Table 3) formats

• Standard Definition Television (SDTV) offers 

about the same picture resolution as today’s 
NTSC TV, but the picture quality is improved 
because of the lack of snow and ghosts that 
accompany normal NTSC over-the-air broad-
casting. 
Multiple channels are possible with SDTV since
the 6-MHz signal space allotted for digital 
broadcasts can be used for other types of less 
data filled format programming.

• Standard Definition Television (SDTV) refers to

the product/system with the following perfor-
mance attributes:
- Resolution: display resolution lower than that 

of HDTV

- Aspect Ratio: none specified
- Audio: produces useable audio
- Receiver: receives all ATSC (Table 3) formats

and produces a useable picture 

all other commercial stations must construct digital facilities by May 2002
(non-commercial stations, such as PBS affiliates, by May 2003)

(width to height)

(pixels across screen

width)

(Viewable Scan

Lines)

(transmitted per

video frame*) 

refer 

to the method in which the video 
from a picture telecast is scanned 
or displayed on the TV screen.
- Interlace scans or paints half 

the vertical lines for the picture 
on the screen every 1/60 of a 
second. Then the rest of the pic-
ture is filled in between the lines
of the first half on a followup 
scan. The speed of this process 
is so fast that it appears to the 
eye as being one complete pic-
ture. Due to the amount of infor-

mation contained in a 1080-line 
HD picture, interlace is needed 
to fit the format into the allotted 
6MHz channel space.   

- Progressive scans or paints the 

entire video picture one line 
after another. Used with today’s 
computer monitors this progres-
sive process can eliminate some 
of the picture artifacts found 
with interlace scan, but does 
require a larger bandwidth in 
order to deliver programs at the 
same frame rate.

8

Q: What are the goals of DTV? 
A: In the United States the commit-
ment for free and local digital
broadcasts is a main standard for the
new ATSC system. The reception
and interaction of local terrestrial
broadcasting for DTV programming
is to remain the same regardless of
the region or area of the country in
which you reside. 

Q: How long will the transition to
DTV take?

A: The move to digital program-
ming will shift from initial select
program offerings; to increased
simulcast availability; to the ulti-
mate return of analog NTSC broad-
cast channels to the federal govern-
ment in 2006. The NTSC and ATSC
systems will coexist for years to
come (with possible date extensions
provided for the return of NTSC
system channels if needed.)
Products such as the HD6400W
DPTV are uniquely positioned with

operation capability matched for
both the NTSC and ATSC systems. 

Q: What’s in the future for DTV? 
A: Because of the computer, multi-
media, and broadcast services
involved in setting ATSC and signal
compression standards, DTV picture
formats can be universally adopted
not only for TV broadcasts but also
for computer and other interrelated
web and network service purposes.   

Digital Television (DTV) is the umbrella term used to describe the new digital television system adopt-
ed by the FCC. DTV is an open standard with few specific format rules for the implementation of
HDTV/SDTV/and a host of potential data broadcast applications. Although there are certain guidelines
for frequency/bit rates/transmission power/etc. the FCC has taken the position that the marketplace
should decide or dictate what formats will best serve the public.    

The interlace scan process was first used with
NTSC broadcasts to conserve video bandwidth
space. With certain scenes or video material
the interlace process can cause image blurring
or other visual screen artifacts.

(Separate scans sent every 1/60 of a second) 

*60 frames per second
(fps) for live video; 24
and 30 fps for material
produced in film.

FOR BROADCAST