High QoS and High Picture Quality Enable the HD Revolution

Abstract

The goal of MPEG-4 AVC (ITU-T H.264) is to achieve the same picture quality as MPEG 2 at one-half, or even lower, bit rates. Fujitsu has recently developed an advanced MPEG-4 AVC Codec, optimized for content contribution and distribution. The Codec is able to encode and transmit high-quality realtime HD video at low bit rates over both DVB-ASI and IP networks. One limitation of using broadband networks for video content is packet loss. When realtime video is transmitted over a public network, packet losses can result in degradation of video quality Simple forward error correction (FEC) can recover some amount of packet loss, but is ineffective for multiple packet losses. Two technologies have been developed for recovering large packet losses. A scalable FEC and Automatic Repeat reQuest (ARQ) are used to recover data when multiple packet losses occur. And, by carefully combining scalable FEC with ARQ, a TCP-friendly, highly efficient packet loss recovery technology for its IP-based video Codecs has been developed. Low latency and low bit rate encoding has also been implemented in the Codec. HD video can be encoded and decoded at a latency of less than 300 ms with exceptional picture quality. This feature has great promise for enabling the widespread adoption of HD electronic and satellite newsgathering (HD-E/SNG).