This paper explores the recent evolution of Audio Visual (A/V)technology from an analog to a digital format, and discusses the effects of the convergence of A/V and Information Technology (IT) disciplines. Analog A/V infrastructure will lose relevance as the benefits of digital connectivity gain greater market importance. For professionals involved in the purchase, use, specification, or integration of media access systems it is important to be aware of how, when, and why our media technology is evolving and what we must anticipate to ensure maximum utility and performance from projects.
Analog sunset, although seldom acknowledged as such, is the inevitable product of a field of study called "information theory." Information theory is a branch of applied mathematics, electrical engineering, bioinformatics, and computer science involving the quantification of information. Information theory was developed by a mathematician, electronic engineer and cryptographer Claude Shannon, and was first known as "communication theory." In 1949 Shannon published a paper titled A Mathematical Theory of Communication where-in he focused on the best method to encode information for transmission.1 In just over a half century, Shannon's work has become the foundation of the digital revolution and any device containing a microprocessor can claim his work as its notional genesis.
Shannon's work to find the fundamental limits of signal processing operations, such as compressing, storing and communicating data, shone a light on a line of thinking that was further expanded by H. Marshall McLuhan, who is best known for coining the phrase "themedium is the message."2 McLuhan's great insight was that the medium used to deliver content can affect society as much as thecontent itself. Put another way, the storage and transportation format (the medium, and in the case of this paper that means digital video and audio) has a profound effect on the creation, application, utilization, and meaning of the actual content.
Joseph D. Cornwall, CTS, ISF-C, DSCE, ROI Technology Evangelist at C2G
Joe Cornwall has worked in the commercial AV industry for more than two decades. He's held management and technical positions with Sony, General Instrument and Motorola Broadband Communications Sector. Cornwall was a founding member of C-Big, the C-Band Industry Group and served as a member of the Board of Directors for the Satellite Broadcasting and Communications Association (SBCA) from 1999 through 2003. Today Joe Cornwall holds the position of Business Development Manager for C2G, where he's responsible for promotion, support and growth of a full complement of connectivity solutions, including the award-winning RapidRun® line of products. Cornwall holds CTS, DSCE, ISF-C and ROI industry certifications and is a graduate of Massasoit State College and the University of Cincinnati.
Bits are fungible. By this we mean that a device doesn't care if the 1s and 0s that it stores and manipulates are bytes that describe an executable program, an Excel spreadsheet, a PowerPoint presentation, a piece of music, or video content. To the machine they are all the same—just pulses of data. It is when that data represents a copyrighted work that the fun begins.
Analog sunset is a global change. It describes the ordered transition from analog over-the-air television broadcasting (and that ultimately includes both CATV cable television and satellite television) we've enjoyed since its adoption by the NTSC in 1948 to a new digital system.3 It is sometimes referred to as digital switchover or analog switch-off. Analog sunset began in 2006 with theNetherlands and moved to Finland, Sweden, and Switzerland in 2007. In 2009 the United States began its transition to a digital broadcast infrastructure4, followed by Denmark, Germany, Norway, Canada, Italy, Israel, and nearly every other country one canname. The full transition to a global standard of digital broadcast is expected to continue until sometime in 2024.5
Digital broadcasting offers many advantages over its analog predecessor. Image resolution and color quality can be precisely specified, resulting in a more controlled and higher quality viewing experience. More information can be carried by a digital broadcast, including detailed guides and menus, additional soundtracks, 3D content, and countless other capabilities. An evengreater benefit is efficiency; digital broadcasts offer more of everything while demanding less RF spectrum than earlieranalog systems.
It should be clear at this point that broadcast video is in the process of migrating towards an all-digital environment and analog capabilities will be eliminated at a global level. Whether over-the-air, CATV or SATV, television has become a digital medium.
At the end of 2010 another aspect of analog sunset appeared, as did another application of the term. Digital content isn't copied, it is cloned. A digital copy is a perfect copy, so systems that protect the intellectual property rights of the content creators from unauthorized duplication and distribution are necessary.
On January 1, 2011, only Blu-ray DVD players that limited their high definition video output to a digital High Definition Multimedia Interface (HDMI) connection could be sold in the United States. Players sold before that date would have their analog component video connections rendered inoperable for high definition content through the use of a digital "Image Constraint Token" (ICT) embedded in copyrighted material. A digital constraint token allows the source device to scale the image quality down to a lowest common level, and in the case of digital video that's 480i. This has also been referred to as analog sunset.
By 2013, "Digital-Only Tokens" (DOT) that will completely eliminate analog output capability at any resolution during playback of copyright-protected digital high definition material will be in use. If a system uses a DOT, the output will be blanked so long as the demand for copyright protection via HDCP is in place and the system senses a non-HDCP compliant condition.
This use of ICT and DOT technology is defined in an international, cross-industry set of rules known as the Advanced Access Content System (AACS). Created by a consortium of companies including IBM, Intel, Panasonic, Sony, Disney, Warner Brothers, Microsoftand others, AACS is a specification for managing content stored on prerecorded and recorded optical media and is designed for use with PCs and CE devices.6
We now see that, although not technically part of digital switchover as seen from a broadcast point-of-view, prerecorded media has similarly migrated towards an all-digital environment where analog connectivity can be precluded by the technology itself. Prerecorded video content has become a digital medium.
If content accessed from a prerecorded source must be protected from illicit copying, what about content that is broadcast or downloaded? Isn't a clone/copy of a high definition broadcast functionally equivalent to a recording of the same content from anoptical disc? The answer is obvious, and this is where the concept of analog sunset begins to bend back on itself and becomes the larger issue we must address today.
The Federal Communications Commission (FCC) made provisions for a digital broadcast flag, which is a digital "lock" designed to control access to content.7 In "Digital Broadcast Television Redistribution Control" the FCC ruled that "no party shall sell or distribute in interstate commerce a Covered Demodulator Product that does not comply with the Demodulator Compliance Requirements," and that hardware must implement functionality to "actively thwart piracy." This was to ensure that digital content that was broadcast over a digital medium (be that OTA, CATV or SATV) could not be illegally copied or distributed. This precipitated much concern and discussion over fair use rights, which subsequently resulted in several legal challenges. After much litigation the FCC's broadcast flag system was finally eliminated in August of 20118, but not before motivating virtually every other method for the electronic distribution of content to implement its own digital rights management initiative.
The DVB Content Protection and Copy Management standard is similar to the FCC broadcast flag and describes how content will be controlled for European digital television. It protects audio-visual works, including films and television programs after they've been received by a consumer, to ensure that the usage is managed in accordance with the rights granted by the content owner or broadcaster.9 DVBCPCM is in use today and affects as many as 900 million receivers on every continent. DVBCPCM also has a wide scope, affecting packaged media, broadband on-demand, broadcast, and mobile delivery.10
E-Books, music and video content (in any variation of streamed, downloaded or delivered via a physical medium), computer games, software programs, and virtually every other conceivable form of digital content have implemented some form of digital rights management.11 And in the United States the FCC isn't done yet—Congress is still considering legislation that could again implement a version of the broadcast flag. Because so much of this content is intended to be accessed via a television display, it should come as no surprise that they all tend to leverage the same physical layer connections and communication protocols.
Often erroneously referred to as "High Definition Copyright Protection," High Bandwidth Digital Content Protection (HDCP) is a content protection system developed by Intel Corporation.12 HDCP leverages a key exchange protocol proposed by the Swedish cryptographer Rolf Blom, decades before digital video became a reality. This encryption system is called Blom's Scheme.13 HDCP is intended to prevent encrypted content from being played on unauthorized devices or devices which have been modified to copy HDCP content. Before sending data, a transmitting device checks that the receiver is authorized to receive it. If so, the transmitter encrypts the data to prevent eavesdropping as it flows to the receiver.14
HDCP is built into three categories of devices; the source (player), the sink (display), and the repeater (switcher, selector, or distribution splitter). The source is the device that sends the content to be displayed and includes computer graphics cards, satellite and cable broadcast receivers, prerecorded media players, and digital video recorders. A version of HDCP, called HDCPv2.x, is also included in the nascent WirelessHD and Miracast standards.
The sink is the video display and may be a computer monitor, LCD or plasma video panel, or a projector. A repeater is a device that switches, processes, distributes and routes the content and includes devices such as home theater A/V receivers, matrix switchers, source selectors, and other distribution devices. Each of these devices must contain HDCP transmitters or receivers to maintain HDCP compliance.
The HDCP "handshake" is most commonly transmitted over HDMI or DVI-D connections, but DisplayPort++ is also HDCP compliant.15 Analog connections like component video or VGA (HD15) do not support HDCP. The installed market for these HDCP compliant devices is enormous. Over three billion HDMI-enabled (and by extension, HDCP-compliant) devices are in use as of early 2013!16
The case is becoming clear. Once A/V content is in the digital domain it has significant hurdles to clear before it can re-enter an analog pathway, if it can do so at all.
The IT industry is not immune from its own evolution that will affect how A/V content is treated on its way out of a computer. Low Voltage Differential Signaling (LVDS) is a physical layer specification that describes the way signals move between inputsand outputs on IC chips. In use since 1994, LVDS is typically used for digital video and graphics data transfers. LVDS became an increasingly important technology when common computer resolutions began to escalate beyond SVGA (800x600 pixels). Until February 2013, BLVDS (Bus LVDS) and LVDM (Multipoint LVDS) has remained a major technology, implemented on a variety of devices.17
On December 8, 2010 a joint press release from AMD, Dell, Intel Corporation, Lenovo, Samsung Electronics LCD Business, and LG Display announced "intentions to accelerate adoption of scalable and lower power digital interfaces such as DisplayPort and High Definition Multimedia Interface (HDMI) into the PC." The press release went on to say that "Intel plans to end support of LVDS in 2013 and VGA in 2015 in its PC client processors and chipsets."18 This love-loss for LVDS is, in part, a result of the need to ensure HDCP compliance and to manage the ability to transmit high definition signals to multiple display devices. A packetized exchange protocol, working at lower voltages than LVDS while still maintaining good compatibility with chip-level fabrication, was needed. It exists, and is called DisplayPort.
DisplayPort is a digital display interface standard developed by the Video Electronics Standards Association (VESA) and is designed to facilitate the transfer of video, audio, and data between a source and sink. Dual mode DisplayPort (DisplayPort 1.2, commonly known as DisplayPort ++) is capable of emitting HDMI or DVI-D TMDS signals through the use of a simple passive converter.19 DisplayPort has been HDCP compliant since the DP1.1 standard. In January of 2013, VESA further refined the DisplayPort standard to ensure performance commensurate with new HDMI 1.4 capabilities, including support for 4K resolution and 3D video content.20
DisplayPort is replacing LVDS on most computers because of its rich feature set, its compatibility with CMOS fabrication techniques, and its compatibility with HDMI and HDCP technologies. DisplayPort was included in about 1-in-20 commercial desktops and 1-in-50 laptops as of 2009. DisplayPort use is expected to be included in 19-of-20, or 95%, of all computers by 2014 as the industry continues to phase out LVDS. Much of this exponential growth in DisplayPort++ deployment is expected to occur in 2014 and 2015.21
Analog Video Graphics Array (VGA) connectivity (also called an RGB, D-sub 15, mini sub D15, mini D15, DB15, HDB15, HD15 or HD15 connector) is rapidly losing market relevance. After a quarter century of use, we are seeing a profound change seep into computing technology as the demarcation between traditional A/V and IT devices blurs. The newest generation of thinner, lighter "ultra-book" portable computers and the small, ergonomic footprint of personal digital devices like the latest interactive tablets simply don't have the form factors to support the larger, thicker 15-pin traditional analog connection. When coupled with the ever increasing demand for universal compatibility with HDCP-enabled displays and routing devices, the forecast for VGA isn't very bright.22 Most industry insiders believe VGA connectivity will be largely irrelevant by 2017.
HDMI has already pushed analog connectivity out of the consumer realm through the need for near-universal compliance with HDCP for prerecorded HD content.23 Industry experts believe HDMI-enabled devices will grow by more than 19% per year from 2012 through 2016.
DisplayPort is expected to grow by more than 30% per year over the same four year period from 2012 through 2016.
According to a January 2013 Business Wire article; "the increasing demand for HDMI in plasma/LCD TVs is one of the major growth drivers for the Global HDMI and DisplayPort-enabled equipment markets. However, the advancement in technology and the increase in user preference for high definition products have caused the adoption rate to grow much more rapidly."24
Historical trends point emphatically to the fact that our society's communication content is increasingly affected by the technology in which it's wrapped. From the moment that stereo MTS sound was added to television broadcasts in 1984, we've been moving along a path of convergence. Convergence first meant the confluence of audio and video disciplines. As that goal was met, convergence came to encompass the concurrence of computing and media consumption, and opened vast new opportunities for interactive enjoyment of movies, music, images, text, and data. What we read, watch, and listen to is invariably affected by the medium through which we access it, and that medium is increasingly—and almost exclusively—digital in nature.
As the market continues to demand unfettered access to copyrighted broadcast and downloaded content on all manner of devices from smart phones to tablets, and from laptop computers to sophisticated home theater installations, it is fair to expect the requirement of HDCP compliance and high definition performance to also grow.
HDMI has captured the market as a digital connection between a multimedia source and a display. DisplayPort has captured, or is in the process of capturing, the market as a digital connection between a computer source and A/V devices. In neither of these applications, nor in any geographic market, are analog connections still a viable commercial alternative.
While it is possible to consider analog sunset from a very limited point of view and conclude that it does not apply to video equipment not associated with AACS-encrypted Blu-ray Disc playback or to broadcast analog switch-off, the market realities tell a different story. Convergence is moving the market towards a unified perspective where the lines between commercial and consumer applications are as blurred as the lines between A/V and IT. Convergence will deliver us into a future where a version of DisplayPort is our connection with IT content and a version of HDMI is our connection with A/V content. The two technologies will meet in a digital middle where there is no room for analog.
1. C. E. Shannon, "A Mathematical theory of communication," October 1948. Online. Accessed 19 February 2013.
2. Wikipedia, "The Medium is The Message," Online. Accessed 19 February 2013.
3. Digital terrestrial television Activation group, "Analogue Switch-off," 2008. Online. Accessed 19 February 2013.
4. NTIA, "Digital television transition And Publich Safety," 5 February 2006. Online. Accessed 19 February 2013.
5. Wikiepedia, "Digital television transition," Online. Accessed 19 February 2013.
6. AACS LLC, "AACS Specifications," Online. Accessed 19 February 2013.
7. Gerard M Stegmaier, Pike and Fisher, "DMCA 2005 Supplement," 2005. Online. Accessed 19 February 2013.
8. Neil Grace, FCC, "Genachowski Continues Regulatory Reform," 22 August 2011. Online. Accessed 19 February 2013.
9. DVB, "DVB-CPCM," May 2011. Online. Accessed 19 February 2013.
10. DVGB LLC, "DVB-CPCM," 2013. Online. Accessed 20 February 2013.
11. X. Zhang, "A Survey of Digital Rights Management Technologies," 2012. Online. Accessed 19 February 2013.
12. DCP LLC, "About DCP," Online. Accessed 19 February 2013.
13. Blom, "An Optimal Class of Symmetric Key Generation Systems," 1985. Online. Accessed 19 February 2013]. 14. DCP LLC, "Digital-CP.com," 2008. Online. Accessed 20 February 2013.
15. Wikipedia, "High-bandwidth Digital Content Protection," Online. Accessed 19 February 2013.
16. HDMI LLC, "HDMI.org," 8 January 2013. Online. Accessed 19 February 2013.
17. Wikipedia, "Low-voltage Differential Signaling," Online. Accessed 19 February 2013].
18. Nick Knupffer, Intel, "Intel Newsroom," 8 December 2010. Online. Accessed 19 February 2013.
19. DisplayPort LLC, "DisplayPort.org," 2013. Online. Accessed 19 February 2013.
20. VESA, "VESA," 2013. Online. Accessed 19 February 2013.
21. Richard Adhikari, TechNewsWorld, "VGA given 5 Years to Live," 9 December 2010. Online. Accessed 19 February 2013.
22. Agam Shah, IDG News Service, "PC World," 31 July 2012. Online. Accessed 19 February 2013.
23. B. Drawbaugh, "engadget.com," 10 January 2011. Online. Accessed 19 February 2013.
24. Business Wire, "Business Wire," 25 January 2013. Online. Accessed 19 February 2013.
This white paper is for informational purposes only and is subject to change without notice. C2G makes no guarantees, either expressed or implied, concerning the accuracy, completeness or reliability of the information found in this document.