Q+A CENTER

COVER STORY

Fully Programmable Digital Media Processors

Real-time processing for high-performance video & imaging designs

By Vishal Markandey and Pradeep Bardia

November 2002

The most common processing architectures used in video and imaging applications today are application-specific integrated circuits (ASICs), microprocessors or programmable media processors. While a number of variables influence a designer's choice of processor, there are market-driven factors that point to an increasing need for programmable solutions. Some compel an even higher level of flexibility with software integration enabling designers to meet rigorous, fast-changing standards. Cost and time-to-market are key issues in the design cycle. The forward trend seems to point toward turnkey system solutions for a broad array of functions so design time can be applied to real product differentiation.

ASICs are advantageous when implementing fixed function applications, because the ASIC designer can optimize the ASIC for processing performance and cost. An example is the MPEG-2 decode function in set-top boxes.

Microprocessors offer the advantage of full software programmability and, with rapid strides in processing performance, are now able to offer the compute performance required by high-performance video and imaging applications. For example, microprocessors have found use in certain high-end systems for machine vision and media servers. However, they are limited from being an ideal match in many video and imaging applications due to a lack of integrated multimedia peripherals, power inefficiencies and cost.

Fully programmable digital media processors offer the ideal combination of performance, integrated multimedia peripherals and full programmability, along with the power and cost requirements needed for today's applications. Digital video processing drives such apps as machine vision, medical imaging, security monitoring, digital cameras/printers and consumer applications including DVDs, Digital TV, video telephony and others. These are characterized by requirements for processing flexibility, sophisticated algorithms and high data rates.

Media processing applications today are required to address a variety of different standards and application scenarios. As an example, the primary video processing component of set-top boxes has been based on MPEG-2. However, set-top boxes developed today must additionally address other applications such as streaming media over broadband, video-on-demand and video telephony. This may require the set-top box not only to perform MPEG-2 video decode, but also decode/encode other formats such as MPEG-4, proprietary streaming media formats and H.26x formats for video telephony.