Encoding technology
Mar 1, 2009 12:00 PM, By Carl Furgusson
Coding advances point to a new generation of MPEG-2.
The last decade has seen an estimated 40-fold increase in processing power in commercial, off-the-shelf silicon. Approaches to coding MPEG-2 once considered economically unviable are now within the realms of possibility. After years of marginal gains, the digital TV industry could see a revolution in MPEG-2 compression efficiency, providing a much-needed economic enabler for new service delivery.
Rate optimization and rate-distortion optimization will be at the heart of next-generation MPEG-2.
MPEG-4 AVC (H.264) was brought to market as the successor to MPEG-2, and, given its ability to revolutionize satellite HDTV business models and get telcos into the TV business, the new codec has enjoyed center stage since 2005. The last three years delivered around 5 percent total efficiency improvements in MPEG-2 as encoder vendors worked on techniques such as better noise reduction and coding optimizations. With diminishing efficiency returns for MPEG-2 development, work in this codec has tailed off, even though MPEG-2-based SD services and viewers have continued to increase.
Given the number of MPEG-2 set-top boxes in the field, it has become apparent during this three-year hiatus that MPEG-4 AVC will continue to complement rather than replace MPEG-2. We can expect at least another decade of coexistence. As an alternative to increasing transmission OPEX costs, or costly attempts to recover valuable network bandwidth, digital TV pioneers with large MPEG-2 set-top box populations need another dramatic shift in MPEG-2 compression efficiency to expand their service offerings within their existing network capacity. Service expansion could mean adding more SD channels or squeezing SD bit rates to make room for HDTV, on-demand services or faster broadband. The digital TV industry would welcome a new generation of MPEG-2 if it meant offering new services within today’s transmission OPEX.
Contrast that with the next three years, which could deliver a 15-30 percent efficiency boost. This achievement relies on three main factors: a quantum leap in silicon processing power per dollar, making advanced techniques affordable within MPEG-2 SD business models; transferring lessons learned in MPEG-4 AVC into MPEG-2; and fresh approaches to MPEG-2 coding implementations.
| Want to use this article? Click here for options! |  |
