Complexity/Performance Analysis of a H.264/AVC Video Encoder
Hajer Krichene, Ahmed Chiheb, Mohamed Abid, Abderrazak Jemai · InTech eBooks · 2011
The evolution of digital video industry is being driven by continuous improvements in processing performance, availability of higher-capacity storage and transmission mechanisms. Getting digital video from its source (a camera or a stored clip) to its destination (a display) involves a chain of components. Key to this chain are the processes of compression and decompression, in which bandwidth-intensive raw digital video is reduced to a manageable size for transmission or storage, then reconstructed for display (Richardson, 2003). The early successes in the digital video industry were underpinned by international standard ISO/IEC 13818 (ISO/IEC, 1995), popularly known as MPEG-2. Anticipation of a need for better compression tools has led to the development of the new generation H.264/AVC video standard. The H.264/AVC is aiming to do what previous standards did in a more efficient, robust and practical way, supporting widespread types of conversational (bidirectional and real-time video telephony, videoconferencing) and no conversational (broadcast, storage and streaming) applications for a wide range of bitrates over wireless and wired transmission networks (Joch et al., 2002). The H.264/AVC has been designed with the goal of enabling significantly improved compression performance relative to all existing video coding standards (Joch et al., 2002). Such a standard uses advanced compression techniques that in turn, require high computational power (Alvarez et al., 2005). For a H.264 encoder using all the new coding features, more than 50% average bit saving with 1–2 dB PSNR (Peak Signal-to-Noise Ratio) video quality gain are achieved compared to previous video encoding standards (Saponara et al., 2004). However, this comes with a complexity increase of a factor 2 for the decoder and larger than one order of magnitude for the encoder (Saponara et al., 2004). Implementing a H.264/AVC video encoder represents a big challenge for resourceconstrained multimedia systems such as wireless devices or high-volume consumer electronics since this requires very high computational power to achieve real-time encoding. While the basic framework is similar to the motion compensated hybrid scheme of previous video coding standards, additional tools improve the compression efficiency at the expense