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 for 525i (480i) as VBI data on line 20 Also specified on line 41 for 520p in IEC , 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

CGMS-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 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