ClearOne Digital Media - Manual (Page 27)

DRM can even be used to implement use constraints on non-copyrighted works, examples
include the placement of DRM on certain public-domain or open-licensed e-books, or
DRM included in consumer electronic devices that time-shift both copyrighted and non-
copyrighted works.
For the AV professional the most relevant discussion around DRM is to define transfer
stream DRM as compared with DRM encryption for digital files. Example: High-bandwidth
Digital Content Protection (HDCP) compared with Microsoft PlayReady DRM.
High-bandwidth Digital Content Protection (HDCP) is a form of digital copy protection
developed by Intel Corporation and is used to prevent copying of digital audio and video
content as it moves across DisplayPort, Digital Visual Interface (DVI), High-Definition
Multimedia Interface (HDMI), Gigabit Video Interface (GVIF), or Unified Display Interface
(UDI) connections.
HDCP does not allow copying permitted by fair use laws, rather the system is meant to
stop HDCP-encrypted content from being played on devices that do not support HDCP or
have been modified to copy HDCP content. The HDCP system works as follows. Before
sending data, a transmitting device verifies that the receiver is authorized to receive it, and
if so, the transmitter then encrypts the data as it flows to the receiver. This is an example
of a transport stream DRM which is primarily what the average AV professional will come in
contact with. However, a complete understanding of digital file encryption is also required,
lest a file be attempted to play and the user presented with a dreaded, “file not authorized”
error message.
In contrast, Microsoft PlayReady DRM is one example of a system which protects digital files
and enables content services and device manufacturers to make more content available
to consumers without fear of losing control and revenue of their high value digital assets.
PlayReady fully supports domains and embedded licenses, making it simpler for consumers
to transfer and play content on a wider range of devices. Microsoft’s PlayReady technology
supports a wide range of audio and video formats, including Windows Media Audio (WMA),
Windows Media Video (WMV), Advanced Audio Coding (AAC), AAC+, enhanced AAC+,
and the H.263, and H.264 video codecs. It also moves beyond audio and video to support
games, images, and ringtones. In addition, it supports many business models for content,
including purchased downloads, subscription, rental, preview, and pay-per-view which
have now all become an essential part of premium service offerings gaining mainstream
consumer adoption.
pg 27 StreamNet Digital Media and System Design Reference Guide
Digital File Security and DRM