The basic objective of all video coding encoding algorithms is highly specified to achieve a comprised balance with complexity of the methodical solution and optimizing the resultant efficiency that includes transporting the image either viva single route or through distributed resources. Typically video codec are video coding standards to achieve highest video quality in lesser time. A video stream is a frame of picture split from video format. The high-computational video complexity and real-time requirements of video systems represent the main challenges to overcome on the development of efficient encoder solutions. Generally it is considered important if the encoding phase complexity scalability is proportional to temporal and spatial resolution.
There have been many advancement in the development of video coding standard, major achievement was the well known standard H.262/MPEG-2. The standard was the outcome of the partnership between Moving Pictures Experts Group (MPEG) and Video Coding Experts Group (VCEG). VCEG is former and attentive towards conventional video coding goals such as packet-loss and compression where as MPEG is ambitious towards synthetic-natural hybrid coding and object oriented video coding. Further one from there, the evolution picked up and resultantly published new standard H.264/MPEG-AVC which gave 50% efficiency compared with previous standards. The design of H.264 have Fidelity Range Extensions (FRExt), Multiview Video Coding (MVC) extension and Scalable Video Coding (SVC) extension. After the introduction of H.264, in 2010 H.265 was published from the merging of two video coding experts namely ISO MPEG and ITU VCEG, establishing a Joint Collaborative Team (JVT-VC). H.265 is a compatible video coding standard, that manges to be able to work for every h.24x series applications. Besides JVT-VC, other companies have also introduced their own particular video coding standards, few of them are listed below.
High Efficiency Video Coding is advanced video coding standard from previous standard H.264/AVC. In 2003 AVC was published and used in HD television. H.265 increases compression efficiency by two times and also due to its compatibility with every other video standard application it would be replacing H.264. Later in the report H.265 structure have been discussed in detail.
VP9 is an open source developed video coding standard, which offers saving in network usage, GOOGLE have developed this standard considering their networking issues specifically regarding online video streaming. This standard also have adopted some of similar characteristics of previous video coding standard “AVC”. The major difference is instead of macroblock it uses super block which easily could split adaptively. This technique improves motion vector prediction.
Daala is developed independently from characteristics shared by H.265 and VP9. It is highly based on hybrid coding, which might overtake the video coding industry. It is patent free and considers lapped transformation rather than block-based DFT filtering and intra prediction in frequency domain.
A scene of a real-world is spatially and temporarily sampled in a digital video. The video is sampled in time which generates frames, that represent a scene at a point of time. Samples altogether produce a video signals. To represent a video signal, three components are used, those are
1) High-Definition formats
2) Intermediate formats
3) ITU-R 601 standards
Digital Video Format
Digital video can be represented in form of RGB and YUV/Y4M. Three colors red, blue and green is used to present RGB format. Color intensity (chrominance) and brightness (luminance) can be also adjusted separately in the RGB format. These can be added through calculating weighted sum of the colors thoses are R, G and B. YUV have handover on RGB format, as it can be represented with lower resolution, and not harmful to human visual system (HVS) caused by intense brightness. RGB format can be converted into YUV through following formulas
$ Y = (0.257*R) + (0.504*G) + (0.098*B)+ 16 $
$ U = (0.439*R) + (0.368*G) – (0.071*B)+ 128 $
$ V =-(0.148*R) – (0.291*G) + (0.439*B)+ 128 $
A source image or video sequence is converted into compressed form by video CODEC encoder and a copy is generated at the decoder end. The whole process is considered lossless, if the video received after decoder is identical to the original.