DTVCC Distribution at PBS

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DTVCC Distributionat PBS

• Gregory Forbes
• Transmission System Engineer
• Public Broadcasting Service
• DTV Caption Summit 3/14/01

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Program Distribution Today

• Ku transponder on GE-3 (36MHz)
• Two transport streams - SDTV multicast and HD
  loop
• Demux/decode and reencode equipment not necessary

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DTVCC CLOSED-LOOP TEST AT PBS 3/13/01
ProCap Caption Server
Time Code
Evertz 8075 DTV Caption Encoder
Digital Vision Bitlink HDTV Encoder
Sencore 987 8VSB Modulator
SMPTE 333, using RS-232 port
ASI
RF
HD SDI
Analog Composite Video (with 608 captions)
Sony DTR-HD1 ATSC Decoder
SDI
Baseband Video with derived 708 captions
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PROPOSED HDTV DISTRIBUTION
ProCap Caption Server
Time Code
Evertz 8075 DTV Caption Encoder
Digital Vision Bitlink HDTV Encoder
SMPTE 333, using RS-232 port
U/L ON GE-3
19.39Mbps
HD SDI
Analog Composite Video (with 608 captions)
SDI
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PROPOSED 4-Ch. SDTV DISTRIBUTION DIGITAL VISION
ENCODING
Evertz 8075 DTV Caption Encoder
Digital Vision Bitlink SDTV Config.
SMPTE 333, using RS-232 port
SDI (259M)
608 Byte stripping
SDI (259M)
U/L ON GE-3
19.39Mbps
608 Byte stripping
SDI (259M)
608 Byte stripping
SDI (259M)
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PROPOSED SDTV DISTRIBUTION SA POWERVU ENCODING
Evertz 8075 DTV Caption Encoder
Scientific-Atlanta SD Encoder 1
SA PowerVu Mux
RS-232 (future)
SDI
Evertz 8075 DTV Caption Encoder
Scientific-Atlanta SD Encoder 2
RS-232 (future)
SDI
U/L ON GE-3
19.39Mbps
Evertz 8075 DTV Caption Encoder
Scientific-Atlanta SD Encoder 3
RS-232 (future)
SDI
Evertz 8075 DTV Caption Encoder
Scientific-Atlanta SD Encoder 4
RS-232 (future)
SDI
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Distribution Tomorrow

• Options for two or three transport streams
• Multiplex into one 36MHz TP (8PSK for 3 TS)
• Encapsulate into 45Mbps DS-3, use 2 or 3 TPs
• Multiplex 2 transport streams into 1 DS-3
• Local encoding, PSIP, switching and bug insertion