Broadcast Television Archiving

1
Broadcast Television Archiving

• Rod Hewitt
• rod_at_coolstf.com

2
Current System

• Analog input-based
• Encodes to MPEG-2 Program Stream files
• Initially DLT tape based
• Now uses removable 3.5 inch drives
• Operational since 2000

3
Current System

• Records up to twenty channels on five PCs
• Content from around the world
• More than half of these channels have EPG
• US and Canadian channels have captions
• Operates at a house in suburban MD

4
Current System Issues

• Analog based
• Recodes video that comes in digital
• Caption data is lost in recordings (kept as text)
• Expensive to expand
• A big chunk stops working in February 2009!

5
Digital Future

• The future of broadcasting is digital
• One big lesson learned
• Needs to be geographically redundant
• and therefore inexpensively implemented
• and inexpensive to run long term

6
MPEG-2 Transport Stream

• The worldwide standard for broadcast DTV
• A single analog channel is replaced with a
  digital multiplex
• The multiplex can contain one or more programs
• Encoded with different codecs
• With multiple audio and data streams

7
Digital Archiving

• Splits programs from MPEG-2 transport streams
• One tuner required per multiplex
• Multiplex may contain a number of useful programs
  or just one
• Transparent across the worlds DTV standards
• Works with terrestrial, satellite and cable

8
Digital Archiving

• Splits files based on EPG or a timer
• EPG from in or outside the multiplex
• Extracts captions in North America
• Extracts subtitles in some European countries
• Generates thumbnail pictures of video
• Automatically moves data onto empty drives
• XML index to each event recorded

9
Hardware is cheap!

• For two channel terrestrial
• PC - 400
• Monitor - 150
• Two off-air DVB-T or ATSC cards - 200
• UPS - 200
• Antenna - 50
• Around 1000 per system

10
Storage is cheap!

• 1 TB SATA drives are now typically 179
• With MPEG-2 SD, thats 23 days
• or 46 days with H.264 SD
• and 6 days MPEG-2 HD
• About 8 per channel per MPEG-2 SD day
• Two MPEG-2 SD per year for less than 7000

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Digital Archiving Examples

• Multiplexes from around the world

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European Satellite
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UK Terrestrial
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France Terrestrial
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Finland Terrestrial
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Germany Cable
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Mali Cable
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Dallas,TX Terrestrial
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Columbus, NC Cable
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Brazil Terrestrial
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Broadcast Television Archiving

• Rod Hewitt
• rod_at_coolstf.com