H2.64 is the tenth part of MPEG-4. It is a highly compressed digital video codec standard proposed by the Joint Video Team (JVT, Joint Video Tean) jointly formed by the ITU-T Video Coding Experts Group (VCEG) and the SO/IEC Moving Picture Experts Group (MPEG). This standard is often referred to as H.264/AVC (or AVC/H.264 or H.264/MPEG-4 AVC or MPEG-4/H.264AVC) and explicitly states its developers on both sides. The main parts of the H.264 standard are Access Unit delimiter (access unit separator) SEI (additional enhanced information), Primary Coded Picture (basic image coding), Redundant Coded picture (redundant image coding). There are also nstantaneous Decoding Refresh (DR instant decoding refresh), Hypothetical Reference Decoder (HRD, hypothetical reference decoding), Hypothetical Stream Scheduler (HSS, hypothetical stream scheduler). But now H.264 is gradually being replaced by H.265.
In August 2012, Ericsson introduced the first H.265 codec. Six months later, the International Telecommunications Union (ITU) officially approved the HEVC/H265 standard, which is called High Efficiency Video Coding, which is a considerable improvement over the previous H.264 standard. Huawei has the most core patents and is the leader of this standard. H.265 is designed to transmit higher-quality network video under limited bandwidth, and only needs half of the original bandwidth to play the same quality video. The H.265 standard also supports both 4K (4096×2160) and 8K (8192×4320) Ultra HD video. The coding architecture of H.265/HEVC is roughly similar to that of H.264/AVC, including Intra Prediction, Inter Prediction, Transform, and Quantization, Deblocking Filter, Entropy Coding and other modules. But in the HEVC coding architecture, the whole is divided into three basic units, namely the coding unit (Coding Unit, CU), the prediction unit (Predict Unit, PU) and the transformation unit (Transform Unit, TU).
H.265 is a new video coding standard formulated by ITU-T VCEG after H.264. The H.265 standard revolves around the existing video coding standard H.264, retaining some of the original technologies and improving some related technologies at the same time. The new technology uses advanced techniques to improve the relationship between code stream, encoding quality, delay and algorithm complexity to achieve optimal settings. H.264 can achieve standard definition digital image transmission at a speed lower than 1Mbt/s due to algorithm optimization; H.265 can realize the transmission of 720P (resolution 1280×720) ordinary high-definition audio and video transmission at a transmission speed of 1-2 Mbit/s.