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Copy Generation Management System - Analog. Brian Markwalter Director of Engineering Consumer Electronics Association. CGMS-A History. Initially introduced as an international standard for conveying copy protection states over an analog video interface through vertical blanking interval data - PowerPoint PPT Presentation
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Copy Generation Management Copy Generation Management System - AnalogSystem - Analog
Brian MarkwalterDirector of Engineering
Consumer Electronics Association
CGMS-A HistoryCGMS-A History
• Initially introduced as an international standard for conveying copy protection states over an analog video interface through vertical blanking interval data
• Standardized in IEC 61880 for 525i (480i) as VBI data on line 20
• Also specified on line 41 for 520p in IEC 61880-2, and in EIA-J (without bit meanings)
CGMS-A in US CGMS-A in US StandardsStandards
• Standardized in EIA/CEA-608-B for 525i (480i) on line 21.
• Standardized for component video interface through EIA/CEA-805:– Line 41, 480p– Line 24, 720p– Line 19, 1080i
CGMS-A in EIA-608-BCGMS-A in EIA-608-B
• Contained in 7 bit field• Two bits (b4, b3) are CGMS-A• Two bits (b2, b1) are Analog
Protection System (APS) bits• One bit (b0) is Analog Source Bit
(ASB), signals source is pre-recorded material
• Others reserved
CGMS-A Bits in EIA 608CGMS-A Bits in EIA 608
CGMS-A bits Meaning
0 , 0 Copying is permitted without restriction
0 , 1 Condition not to be used (“No more copies” in EIA-805)
1 , 0 One generation of copies may be made
1 , 1 No copying is permitted
Where CGMS-A Is UsedWhere CGMS-A Is Used
• Required by DVD CCA license for certain applications
• Some DVD recorders respond to CGMS-A on analog inputs
• D-VHS recorders respond to CGMS-A on analog inputs
CGMS-A AttributesCGMS-A Attributes
• A mature technology already implemented on a voluntary basis in many CE devices
• Requires minimal signal processing• Operates in-the-clear• Leverages VBI capability and
protection
Brian MarkwalterCEA