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Do I need to buy a new TV to enjoy
the HDTV programs?
What does "down-convert" mean? What does "up-convert" mean?
     
If your current TV is not “HD Ready” and only able to
receive analog signals, you will need to buy a HDTV set top box (receiver) in order to continue to receive the digital signals. However, due to the display limitation of analog TV, you will not able to enjoy the full benefit that digital broadcast can bring you.
Down-convert takes place when a digital broadcast signal
exceeds the display capabilities of the your television and
the broadcast signal is reduced to match the television's
limited display capabilities. For example, if a channel
broadcasts a digital program using 1080 lines (1080i format) while the your television is only able to display 576 lines, the 1080i signal is reduced or down-converted to only 576 lines, resulting in inferior picture quality.
Up-convert takes place when a digital television's display
capabilities exceed the digital broadcast signal and the
broadcast signal is increased to match the TV's display
program using 576 lines (576i or 576p) and the digital
television is able to display 1080 lines, the signal is increased or up-converted to match the TV, resulting in hazy picture quality
.
Why Digital TV is better than Analog TV?
 
  Consistent quality of TV picture >      
Analog Signal Digital Signal
If signal is weak,picture is weal,lots of static
As long as tv is receiving a signal,picture is
perfect
 
  No more ghosting >
Multi-path reflections between buildings will be handled properly by COFDM technique
Analog TV Digital TV  
 
 
  High Definition TV possible >
Analog TV (Standard Definition)   Digital TV (High Definition)  
           720 horizontal X 576 vertical
           Aspect ratio 4:3
           Stereo Sound
           1920 horizontal X 1080 vertical
           Aspect ratio 16:9
           Multi sound channels (Dolby 5.1)
 
  Multi-Casting >
It allows the user to switch between SD Programs or HD Program with Multi-sound channels.
 
What is the difference between MPEG 2 and MPEG 4?
 
MPEG 2 MPEG 4

The MPEG2 content is created from various resources such as moving video, graphic,
text, it is then composited into a plane of pixels, these are encoded as if they all were
moving video pixels.

At the consume side, decoding is a straightforward operation.

MPEG2 is a static presentation engine: if one broadcaster is retransmitting another
broadcaster coverage of an event, the latter logo cannot be removed. You can add
graphic and textual elements to the final presentation, but your cannot delete them.

The MPEG4 is dynamic

Suited for interactive multi-media delivery systems at any bandwidth.
(from DMB-TH to HDTV)

MPEG4 is object-based, construct mul.

User can interact with objects in the scene: to change color of a car to see how it look,
to tag a player on the field and watch all their moves, or personalize enhancements to
an enhanced video program.

MPEG4 opens up new revenue otimedia scenes whick revolutionize the possibilities of
interactive mediapportunities through the intergration of back office systems including
transaction / e-commerce systems.
 
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