Samsung DIRECTV SIR-TS160 - Manual (Page 12)

Chapter 1: Technical overview
Resolution and interlacing
Two of the elements that determine the quality of a TV picture are resolution and
interlacing.
• Resolution: For TV equipment and broadcasts, resolution is defined by the
number of horizontal lines displayed to make up each frame of a video
image. The more lines of resolution used to draw each frame of video,
the more detailed and sharp the picture will be. Standard TV resolution
uses 480 horizontal lines to make up each frame of video. HDTV uses
either 720 lines, or 1080 lines to make each video frame.
• Interlacing: When TVs display video, they display a new video frame at a rate
that is faster than your eye can see (from 24 to 60 frames per second,
depending on the TV and broadcast). Interlacing refers to whether
each of those frames contains all of the lines of video for each frame
or every other line. Interlaced signals take every other line from 2
frames of video (each lasting 1/60th of a second), and combine them
into one frame lasting 1/30th of a second. In this way, interlacing tricks
your eye into thinking it is seeing twice the resolution that is actually
being displayed.
In non-interlaced video, (referred to as progressive scan video), video
frames are displayed every 1/60th of a second containing all of the
lines of video information for each frame.
The specifications for video resolutions are usually stated by giving the number of
horizontal lines, followed by either the letter i, for interlaced video, or p for
progressive scan video. Most standard TV broadcasts are 480i (480 lines of interlaced
video resolution). Some DVDs and non-HDTV digital TV broadcasts use 480p. The
ATSC specification for HDTV broadcasts and equipment requires either 1080i or
720p. While there is some debate as to whether it is better to have more lines that
are interlaced (1080i), or fewer lines that are progressively scanned (720p), it is
generally accepted that 1080i is the highest quality video format.
Video output options
The DIRECTV ® High-Definition Receiver is able to receive broadcasts in any of the
resolutions mentioned above. It can also display programs on TVs capable of
displaying any of those resolutions.
To set up your DIRECTV HD Receiver to handle the combinations of incoming video
formats and TV display capabilities, you simply set the Resolution switch on the back
panel to match the highest resolution your TV is capable of displaying. (If you’re not
sure about your TV’s resolution, see your TV’s manual for this specification.) The
DIRECTV HD Receiver will then do the appropriate conversion from input signal
format to display format.
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