High Definition Television (HDTV) Ching-Kai Huang Wing Ho Leung Feng Guo 11/6/2015 Overview Technology advancements History Why HDTV? Current TV standards HDTV specifications Timeline Application Current status Hardware requirement Conclusion 11/6/2015
Download ReportTranscript High Definition Television (HDTV) Ching-Kai Huang Wing Ho Leung Feng Guo 11/6/2015 Overview Technology advancements History Why HDTV? Current TV standards HDTV specifications Timeline Application Current status Hardware requirement Conclusion 11/6/2015
High Definition Television (HDTV) Ching-Kai Huang Wing Ho Leung Feng Guo 11/6/2015 Overview Technology advancements History Why HDTV? Current TV standards HDTV specifications Timeline Application Current status Hardware requirement Conclusion 11/6/2015 Technology advancements Video cassette recorders (VCR) laser discs (LD) digital versatile discs (DVD) compact discs (CD) digital audio tapes (DAT) high definition television (HDTV) 11/6/2015 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 11/6/2015 Why HDTV? Higher-resolution picture Wider picture Digital surround sound. Additional data Easy to interface with computers 11/6/2015 Current TV Standards NTSC: National Television Systems Committee PAL: Phase Alternation Line SECAM: Séquential Couleur Avec Mèmoire TV Standards NTSC PAL Regions U.S. Channel Bandwidth 6MHz Asia, Europe, France South America 8MHz 8MHz Aspect ratio 4:3 11/6/2015 4:3 SECAM 4:3 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 11/6/2015 Scanning Methods Progressive Scanning vs Interlaced Scanning SCANNING METHOD PROGRESSIVE SCANNING Screen redraw on Whole screen each pass Resolution 11/6/2015 INTERLACED SCANNING Half screen Up to 720 horizontal Up to 1080 horizontal lines lines 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 11/6/2015 Components of HDTV systems analog carrier + digital signals video signals Demodulator digital signals Demultiplexer audio signals 11/6/2015 Image Decoder Decoded video signals Audio Decoder Decoded audio signals Display Processor Display format 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 11/6/2015 Application High definition TV for consumer Medical Purposes Video-on-demand Internet surfing Distance Learning 11/6/2015 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 11/6/2015 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 11/6/2015 Comparison Current TV HDTV 11/6/2015 Comparison (current TV) 11/6/2015 Comparison (HDTV) 11/6/2015 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 11/6/2015 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/ 11/6/2015 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 11/6/2015 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 11/6/2015 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. 11/6/2015