With digital video the rage, what happened to analog video?

With all of the new digital video standards coming into the picture, such as MPEG-4, serial digital interface, digital video interface (DVI) and high-definition multimedia interface (HDMI), there is a common misconception that analog video is dead or dying. The reality is that analog video is very much alive. Over the next several years, however, analog video will migrate away from consumer applications and into professional and industrial applications.

Traditionally, consumer video products have been analog-based and used coaxial, composite and S-video connectors for interfacing video sources to televisions. The initial rollout of 480p progressive scan and 720p/1,080i high-definition video sources used the analog domain to transmit video content over YPbPr, more commonly known as component video. A trend just beginning that we will continue to see is HDMI compatibility in consumer products because HDMI uses the high-bandwidth digital content protection (HDCP) system, which prevents users from illegally copying digital video content.

Most new consumer devices are equipped with single and dual HDMI connectors at both the source and display. HDMI is expensive, but there will soon be plenty of HDMI solution providers allowing electronics manufacturers to add HDMI compatibility at a relatively low cost. Lower cost and the strong push for protecting digital content will cause HDMI to dominate in the consumer market. For legacy and compatibility reasons, analog video will never completely be phased out with the consumer; however, as the availability of digital content increases over the next several years, the use of YPbPr in consumer electronics will begin to decline.

Analog video will continue to dominate in professional, industrial and multimedia applications, such as video matrix switchers, keyboard/video/mouse (KVM) systems, audio/video extenders, projectors and conference room systems. These applications are typically based around the PC, which does not use high-definition video standards, but utilizes high-resolution analog video standards set by the Video Electronics Standards Association (VESA). These standards include the popular XGA (1,024 x 768), SXGA (1,280 x 1,024) and UXGA (1,600 x 1,200) video formats.

Digital video interface (DVI) was designed to be an alternative to the analog standards by providing a digital interface. For various reasons, mostly cost and infrastructure hurdles, DVI has not been adopted by the PC graphics card and monitor manufacturers. Meanwhile, technology advances have increased video resolution in both the PC and monitor, allowing analog video to further establish its dominant position.

Consequently, manufacturers of industrial, professional and multimedia products have continued to develop analog systems with wider bandwidths to support the higher video resolutions. In fact, their end customers, which include higher-education institutions, government and entertainment facilities, are pushing to support future such video resolutions as well. Once installed, these video systems are not replaced regularly. They are expected to support the analog video standards that will be used several years down the line.

Therefore, these manufacturers are designing systems that are perceived to be “overkill” for the application, but in fact, they are in tune with what the market needs.

The worldwide availability of the PC and the demand for information through the PC has increased the popularity of analog video applications. In fact, many studies project a continued growth for analog video in professional, industrial and multimedia applications due to customer demand and the lack of DVI adoption. The true test for analog video will be time. However, until the hurdles of cost, ease of use and adoption are overcome for digital video in the PC, analog video is here to stay in many applications for years to come.

About the author
Tushar Patel is a product-marketing engineer in National Semiconductor's Amplifier Group. He holds a BSEE from Santa Clara University.

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