Digital TV
Flat panel displays (LCDs, plasma display panels,
plasma low-profile, and liquid crystal on silicon) and video projectors
receive, decode, and display digital video streams from a variety
of sources. Frame buffering video is required when supporting
multiple input video formats. LOGIC’s video products line simplifies the task of manipulating and
buffering video and greatly reduces development time and cost.
The heart of the LCD HDTV is its image processing
and timing control block (shown in Figure 1). The image processing
block typically includes functions such as scan rate converter,
frame rate converter, color decoder, motion detection, scalar,
and de-interlacing. Resolution, brightness, contrast and clarity
impact define the visual experience. It is critical for TVs to
support multiple ATSC DTV formats, NTSC and PAL decoding, composite
and S-Video inputs and 2D adaptive filtering. As HDTV rolls forward,
supporting full HD at 1080i resolution with 3D adaptive filtering
will be the standard.
Figure 1. Typical LCD TV Interface Block Diagram
Digital set-top boxes (DSTBs) receive and decode
television broadcasts from satellite, cable, and/or terrestrial
sources. Integrated digital televisions (DTVs) have built-in digital
tuners, demodulators, and source decoders – making set top
boxes redundant.
Traditional DSTBs are designed to receive standard
definition (SD) Moving Pictures Experts Group-2 (MPEG-2) video
format broadcasts. However, many of today’s DSTBs are high-definition
(HD)-ready. In fact, selected cable television service providers,
networks, and local terrestrial TV stations are concurrently transmitting
both SD and HD content. Over time, MPEG-4 will displace the MPEG-2
format for both SD and HD.
High-end DSTBs may also offer personal video
recorder (PVR) and/or a DVD recorder functions. Microcontrollers
in DSTBs or integrated DTVs can perform a number of functions
for these systems, including control panel management and on-screen
display (OSD).
Related links:
- Video Synchronization
- Frame Store
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