ARRIS Enterprises, Inc. Confidential Information

Analog Copy Protection

Introduction

Analog Copy Protection (ACP) refers to the mechanisms for protecting media content against unauthorized copying via the analog video outputs. There are different ways to implement ACP; KreaTV supports CGMS-A and Macrovision. These two technologies can be enabled at the same time as they target different receivers.

Copy Generation Management System - Analog (CGMS-A)

CGMS-A embeds copy control information in the analog video signal, using the vertical blanking interval (VBI) to transmit a few bits of digital information. The copy protection is only enforced by CGMS-A-compatible devices that can interpret these control bits.

KreaTV enables CGMS-A on all STB models that fit an analog output connector. There is no need to include any license or IIP in the boot image configuration to activate CGMS-A support.

CGMS-A can signal four different copy protection policies:

Value	Reference	Remark
0	Copy Free	The content may be copied an unlimited number of times.
1	Copy No More	This content can be copied to a DVR, but cannot be copied or distributed any further.
2	Copy Once	A single copy can be made.
3	Copy Never	No copies may be made of the content.

By default, KreaTV forces CGMS-A to CopyNever; the ability to change this policy is a licensed feature. By adding the kreatv-license-allow-cgmsa-control IIP to the boot image configuration you can disable CGMS-A signaling altogether, or control the policy dynamically from the input stream. Dynamic control at runtime also requires the kreatv-option-drmservice IIP to be present in the configuration.


  # Unlock CGMS-A, allowing policies other than CopyNever
  kreatv-license-allow-cgmsa-control:cgmsa_enabled=true


  # Runtime control of the copy protection policy
  kreatv-option-drmservice

See kreatv-license-allow-cgmsa-control and kreatv-option-drmservice in IIP reference.

Macrovision

Macrovision Analog Copy Protection is a copy control mechanism that distorts the video signal in ways originally intended to mislead the input circuitry present in recording devices. Susceptive devices would produce recordings with wild variations in brightness and color, unusable for playback. Playback-only devices are generally immune to this kind of distortion.

Modern recording equipment is not necessarily sensitive to Macrovision-encoded signals, but some might still recognize them as copy protected content and block the recording.

Macrovision is a licensed technology that requires the set-top box to be certified by Rovi together with the application that will be used for deployment. Additionally, ARRIS must receive explicit written permission from Rovi to enable Macrovision support for a customer. ARRIS STBs running KreaTV are certification ready, but the actual certification and authorization processes with Rovi are only carried out upon request.

To enable Macrovision in the STB, you need to add its license IIP to the boot image configuration. As with CGMS-A, dynamic control of the copy protection requires kreatv-option-drmservice IIP as well.


  # Enable Macrovision copy control on analog outputs
  kreatv-license-ca-macrovision

See kreatv-license-ca-macrovision in IIP reference.