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HDTV.ppt

  1. 12/11/2022 High Definition Television (HDTV) Ching-Kai Huang Wing Ho Leung Feng Guo
  2. 12/11/2022 Overview  Technology advancements  History  Why HDTV?  Current TV standards  HDTV specifications  Timeline  Application  Current status  Hardware requirement  Conclusion
  3. 12/11/2022 Technology advancements Video cassette recorders (VCR) laser discs (LD) digital versatile discs (DVD) compact discs (CD) digital audio tapes (DAT) high definition television (HDTV)
  4. 12/11/2022 History First began in 60’s at NHK, the Japan Broadcasting Corporation. Many different formats were developed in US In Feb 1993, FCC suggested to form an alliance that would eventually create the best possible system In May 1993, Grand Alliance formed
  5. 12/11/2022 Why HDTV? Higher-resolution picture Wider picture Digital surround sound. Additional data Easy to interface with computers
  6. 12/11/2022 Current TV Standards TV Standards NTSC PAL SECAM Regions U.S. Asia, Europe, South America France Channel Bandwidth 6MHz 8MHz 8MHz Aspect ratio 4:3 4:3 4:3 NTSC: National Television Systems Committee PAL: Phase Alternation Line SECAM: Séquential Couleur Avec Mèmoire
  7. 12/11/2022 HDTV and NTSC Specifications HDTV USA NTSC Aspect ratio 16:9 4:3 Largest frame rate 60 frames/sec 30 frames/sec Vertical refresh rate 60 Hz 60 Hz Highest resolution 1080 lines 525 lines
  8. 12/11/2022 Scanning Methods SCANNING METHOD PROGRESSIVE SCANNING INTERLACED SCANNING Screen redraw on each pass Whole screen Half screen Resolution Up to 720 horizontal lines Up to 1080 horizontal lines  Progressive Scanning vs Interlaced Scanning
  9. 12/11/2022 Additional Specs of HDTV  System outlined in the ATSC standard is based on the MPEG-2 Main Profile  Video formats span the range of Main Level to High Level  Audio Compression is based on the Dolby AC-3 system with sampling rate 48kHz and perceptually coded  5.1 Channels of surround-sound audio  Transport subsystem based on MPEG-2 Transport Stream  Packets consist of 188 bytes  RF subsystem is 8 VSB
  10. 12/11/2022 Components of HDTV systems Display Processor Audio Decoder Image Decoder Demodulator Demultiplexer Decoded video signals Decoded audio signals Display format video signals audio signals digital signals analog carrier + digital signals
  11. 12/11/2022 Timeline of HDTV  November 1998: HDTV transmissions begin at 27 stations in the top 10 markets  May 1999: network affiliates in the top 10 markets must show at least 50% digital programming  November 1999: digital broadcasts in the next 20 largest markets  May 2002: remaining commercial stations must convert  2003: public stations must convert to digital broadcasts  2004: stations must simulcast at least 75% of their analog programming on HDTV  2005: stations must simulcast 100% of their analog programming  2006: stations relinquish their current analog spectrum  NTSC TV sets will no longer be able to pick up broadcast signals
  12. 12/11/2022 Application High definition TV for consumer Medical Purposes Video-on-demand Internet surfing Distance Learning
  13. 12/11/2022 Current Status 18 digital TV formats are approved by FCC More than 27 digital channels being broadcast by ABC, CBS, FOX, NBC DirecTV has one HDTV channel Unity Motion is broadcasting three HDTV channels
  14. 12/11/2022 Hardware Requirement Digital Decoder – converts digital signals to analog – allow current TV set to work Digital-Ready TV set – Wide-screen format – progressive scanning HDTV set – Wide-screen format – can receive 18 digital input format
  15. 12/11/2022 Comparison Current TV HDTV
  16. 12/11/2022 Comparison (current TV)
  17. 12/11/2022 Comparison (HDTV)
  18. 12/11/2022 Conclusion The history, standard, application of HDTV have been introduced HDTV has higher resolution, uses progressive scanning and wider screen leading to better perspective on the scene HDTV has a promising future and is believed to replace NTSC in near future
  19. 12/11/2022 References  http://nbcin.kxas.com/hdtv-faq.html  http://www.cato.org/pubs/regulation/reg16n4b.html  http://www.current.org/atvnhk.html  http://sinfonia.net/mike/hdtv/  http://www.hdvision.com/FAQs/970121.0004.html  http://www.zenith.com/main/cool/hdtv.html  http://carmen.artsci.washington.edu/jeb/jebart2.htm  http://web-star.com/hdtv/faq.html  http://web-star.com/hdtv/perspective.html  http://www.kipinet.com/av/av_mar96/feat_hdtv.html  http://bock.bushwick.com/hdtv_ppt/  http://www.cnet.com/Content/Gadgets/Special/HDTV/
  20. 12/11/2022 Q:Analog bandwidth of HDTV signals?  HDTV image size of 1050 by 600 at 30 frames per sec, the bandwidth required to carry that image quality using the analog transmission system is 18MHz. However, it will require more bandwidth to transmit it in digital format.  With the MPEG-2 compression, the bit rate is compressed from more than 1 Gbps to about 20 Mbps, which transmit digitally only require bandwidth 6MHz
  21. 12/11/2022 Q:Aspect ratio of movies vs HDTV?  Aspect ratio of HDTV is 16:9. However, aspect ratio of movies has many different formats: “Movies are always shot so they can be displayed in several aspect ratios at different types of movie theaters, from the shoebox-sized foreign movie houses to the ultra big screen Star Wars jobs.” ----- Franco Vitaliano http://www.vxm.com/21R.107.html
  22. 12/11/2022 Q:Copyright protection for HDTV?  We do not find any group which mention about copyright protection for HDTV.  Currently, broadcast stations sometimes put their logo on the right bottom corner of their analog broadcast programs. We think that this method can still be used as one way for protecting copyright for HDTV.

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