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

703-907-7441bmarkwalter@ce.org