A video codec is a hardware or software component that makes possible the compression of a video file in an efficient way, as well as its subsequent decompression to visualize it. Modern video codecs use the so called “lossy compression”, which exploits the characteristics of the human visual system in order to achieve high compression rates, such as 20:1.
Video compression allows the transmission of high-quality video in real time through low bandwith networks, as well as the reduction of the space needed for its storage. Video codecs are omnipresent in our daily lives, enabling services such as Youtube, NetFlix, video broadcast in DTT, storage of movies in DVD, Blu-Ray, etc.
Double compression ratio, same quality
Efforts in video coding have been directed from the very beginning towards increasing the compression ratio whilst keeping the same video quality. The achievements during the last years have been enormous, ranging from coding standards like MPEG-1 and H262/MPEG2 (still widely used) to the latest standards VP8 and H264/AVC (MPEG-4 Part 10). Currently, we are witnessing the last steps towards finalizing the definition of the next generation of video codecs, called “High Efficiency Video Coding” (HEVC), which will probably be known as MPEG-H Part 2 or just H265, since it will be the successor of H264/AVC. HEVC is being jointly developed by ISO/IEC Moving Pictures Expert Group (MPEG) and ITU-T Video Coding Experts Group (VCEG). HEVC is in the news because during the last February a meeting was held in San Jose (CA, USA) to deal with the completion of the standard definition.
Gradiant has a wide knowledge of the most advanced video coding standards thanks to its direct relation to several of its research lines, where we can remark multimedia protection and advanced video analysis. In both lines, Gradiant is working in low-level processing of encoded video streams, mainly in H264 given its importance in the field of video surveillance, where Gradiant is carrying out an intense research activity. Research in H265 will start very soon.
One of the main achievements of HEVC compared to H264/AVC is to double the compression rate while keeping the same video quality. Another improvement is that the maximum resolution increases up to 7680×4320 (named “Ultra HDTV”) for supporting future services in multiple environments. Just to have an idea about what Ultra HDTV means: nowadays, the highest resolution defined in the Digital Cinema Standard (DCI) is the so-called 4K (4096×1714).
Applications of HVEC
The range of applications envisaged for the new HEVC standard include: cable television through optical/ copper-based networks, transmission of satellite video, terrestrial digital television, telepresence services, remote video surveillance… There is already a draft of the HEVC standard available, and it is expected that the final draft will be released in early January 2013, prior to its ratification as an official standard. From that point, HEVC will be ready for consideration by the video codec manufacturers.
