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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
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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 • 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 Standards • 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-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
Where 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 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 Markwalter CEA 703-907-7441 bmarkwalter@ce.org