H265 Introduction

"H.265 is the new video coding standard manufactured after ITU-T VCEG followed by ITU-T VCEG. H.265 standard surrounded the existing video coding standard H.264, reserved some of the technologies, and The technique is improved. New technology uses advanced technology to improve the relationship between code stream, coding quality, delay and algorithm complexity, to achieve optimization settings. Specific research contents include: improving compression efficiency and improving robustness And error recovery capabilities, reduce real-time delays, reduce channel acquisition time and random access delays, reduce complexity, etc. H264 can be reduced by lower than 1MBPS speed by lower than 1 Mbps; H265 can be implemented 1 ~ 2MBPS transmission speed transfer 720P (resolution 1280 * 720) Ordinary HD video transmission. H.263 can achieve standard definition broadcast-level digital television (720 * 576 required for CCIR601, CCIR656 standard); H264 can be achieved by the algorithm optimization, the standard clearance of digital image transfer can be achieved below 2Mbps; h .264 High profile can achieve a transport bandwidth below 1.5Mbps, implement 1080P full HD video transmission; H265 is more obvious compared to H264 progress, can achieve 1080P (resolution 1920 * 1080) full HD with 1Mbps or less Video transmission. In addition to the improvement in codec, H.265 is also significantly improved in terms of adaptability of the network, which can be well run under complex network conditions such as Internet. Performance improvement In terms of exercise prediction, the next generation algorithm will no longer follow the "macroblock" picture segmentation method, and may use object-oriented methods to directly identify the moving body in the picture. In terms of transformation, the next generation algorithm may no longer follow the algorithm family based on Fu Ye, there are many articles in discussion, including everyone to pay attention to the so-called "super complete transformation", the main feature is: MXN transformation matrix, M More than n, even more than n, the vector obtained after the transformation is relatively large, but the 0 element is large, and the compressed information flow can be obtained after the latter entropy encoding compression. Regarding the computational amount, the compression efficiency of H.264 is more than 1 times higher than that of MPEG-2, and its cost is calculated by at least 4 times, causing high-definition encoding to require 100 gops of peak computing power. Despite this, it is still possible to use the current mainstream IC process and ordinary design technology to design a dedicated hardware circuit that reaches the above capabilities, and its mass production cost is maintained at the original level. After 5 years (perhaps longer), new technologies are accepted as standards, and their compression efficiency should be more than 1 times higher than H.264, and it is estimated that the demand for calculation will still increase more than 4 times. With the rapid advancement of semiconductor technology, it is believed that the mass production cost of the special chip to realize new technologies should not improve significantly. Therefore, 500GOPS may be a new generation of technology for the upper demand of computing power. content • International Telecom Alliance adopts the next-generation H.265 video standard • Interpretation of the next generation video compression standard HEVC (H.265) • Patent "double-edged sword" H.265 standard does not charge the most reliable? • references International Telecom Alliance passes the next generation H.265 video standard H.265 standard will be conducive to network transmission 1080p video On January 26th, Beijing time, according to foreign media reports, the International Telecommunications Union (ITU) has approved the next generation of new video standards, which will help to bring 4K video into the future broadband network, at the same time This new standard can also play high-definition network video content on a low bandwidth mobile network. This new standard is H.265, which is the high efficiency video coding, which is intended to bring high quality network video to a network of low bandwidth. H.265 is used as a new video standard, but also a new standard after H.264 standard. After IPAD and other related devices, H.264 has become the standards used by almost all video publishers. In fact, Apple triggered the dispute in northern the use of H.264 standard and insisted on using HTML5-based video players, especially before the iPad, most videos encoded via the VP6 encoder and played via Adobe's Flash player . The newly approved H.265 standard will make the publisher transmit 1080p video through the network, while the required bandwidth is only half used. After this new standard, users can transfer and view network HD videos not only on the broadband of the family, but also enjoy these services in devices such as mobile phones and tablets, in fact, mobile phones and tablets and other devices are used. More restricted network bandwidth. In this way, network video will be able to more widely popularize among or more mobile networks connected in poor connection. A wide range of broadband connections, H.265 standard will also support higher quality video. With the final emergence of 4K TV, this new standard also has a chance to provide a better video solution. The only problem therefore is - Some networks have not been completed, which will also be difficult to support the data stream required for video transmission. As the H.265 standard passes, only the bandwidth of 20 to 30 Mbps can be used to transfer 4K network flow. In fact, even in accordance with the current invalid tiller, there is still a large number of networks without the standard. Of course, the adoption of the new standard does not mean that we can quickly view the stream video of the compressed or low bit rate. Although software-based encoders may appear at this time, the encoding decoder will be used by large-scale use after embedding chips and hardware. Therefore, before the first H.265 standard hardware enters the market, it may also take 12 months to 18 months, perhaps longer. Once the initial equipment enters the market, we will see a large amount of content will use the advantage of the H.265 standard. According to market research institutions, Mefeedia announced that since IPAD has been launched, the H.264 standard video proportion of H.264 has risen sharply below 10% in less than three years to 84%. The H.265 standards may mean the phenomenon of network restriction, and more HD video will also appear. The industry believes that more efficient codecs can help improve video quality. Interpretation Next Generation Video Compression Standard HEVC (H.265) In the rapid development of the digital video application industry chain, in the face of video applications, the trend of high-definition, high frame rate, high compression ratio, the current mainstream video compression standard protocol H.264 (AVC) is constantly Highlight. At the same time, HEVC (H.265) protocol standards for higher definition, higher frame rate, higher compression rate video applications should be born. This article focuses on the technical highlight of the next-generation video compression protocol standard HEVC (H.265), and is looking forward to the deep changes in the entire industry in future applications. H.264 (AVC) has gradually become mainstream standards in video applications with significant advantages in compression efficiency and network adaptability from the draft in May 2003. According to MeFeedia's data, due to the iPad and other emerging equipment support H.264 hardware acceleration, 80% of the video use H.264 encoding, and as supporting H.264 decoding, this share It will also grow further. However, with the rapid development of the digital video application industry chain, the trend of video applications develop into the following directions is more obvious: L High definition: Digital video application format is fully upgraded from 720 p to 1080 P, in some video applications, and even 4K x 2K, 8K x 4K digital video format; L High frame rate: Digital video frame rate upgrade from 30 FPS to 60FPs, 120FPS or even 240fps; L High Compression Rate: Transport bandwidth and storage space have always been the most critical resources in video applications, so the best video experience in limited space and pipeline has always been the unremitting pursuit of users. Since the digital video applications are facing the above trend in development, if the H.264 encoding continues to use, the following limitations appear: (1) The explosive growth of the number of macroblocks will result in excessive codewords occupied by macroblock-level parameter information such as macroblock prediction mode, motion vector, reference frame index, and quantification level, for encoding The code word in the difference is significantly reduced. (2) Since the resolution is greatly increased, the information of the image content represented by a single macroblock is greatly reduced, which will result in the similarity of low frequency coefficients after the adjacent 4 x 4 or 8 x 8 transformations, resulting in an occurrence A large amount of redundancy. (3) Since the resolution is greatly increased, the magnitude of the motion vector of the same movement will greatly increase, and a motion vector predicted value is used in H.264, and the Sport vector difference coding is the Columbus index code, the encoding method. The characteristic is that the smaller the number of bits used, the less. Therefore, as the motion vector amplitude is greatly increased, the compression ratio of the method for predicting the motion vector and coding in H.264 will gradually decrease. (4) Some key algorithms of H.264 are, for example, two context-based entropy-based entropy methods based on CAVLC and CABAC, and DEBLOCK filtering, etc., are required to be serialized, and the performance is relatively low. This serialization of H.264 is increasingly becoming a bottleneck restricting computing performance for CPUs such as GPU / DSP / FPGA / ASIC. In order to face the above development trends, January 2010, ITU-T vceg (Video Coding Experts Group) and ISO / IEC MPEG (Moving Picture Experts Group) jointly established JCT-VC (Joint Collaborative Team on Video Coding) United organization, Unified development of next-generation coding standards: HEVC (High EffiCiency Video Coding). The HEVC Agreement Standard is scheduled to be officially released in the industry in February 2013, and the entire framework structure has been basically determined. As of April 2012, the JCT-VC Joint Working Group has held the eighth meeting, and released the first version of the internal draft "High Efficiency Video Coding (HEVC) TEXT Specification Draft 6" on February 17, 2012. In July 2012, the first version of public version was released, and the compression efficiency was doubled more than 2 to 4 times the complexity of H.264 standard. The following table lists HM4.0 (HEVC reference code) compared to JM18.0 BD-RATE: Table 1 HEVC compression efficiency lifting data relative to H.264 According to data from the table, in the case of Low delay, HEVC (HM4.0) is 44% relative to H.264 bit rate. Second, the technical highlight of HEVC (H.265) As a new generation of video coding standards, HEVC (H.265) is still a hybrid encoding frame for predicting the increased transformation. However, relative to H.264, H.265 has a revolutionary change in many ways. The technical highlight of HEVC (H.265) is: Flexible encoding structure In H.265, the size of the macroblock is extended from H.264 to 16x16 to 64x64 to facilitate the compression of high resolution video. At the same time, a more flexible encoding structure is used to increase coding efficiency, including coding units, predict units, and transform units. As shown in Figure 1: Figure 1 Coding Unit (Cu), Prediction Unit (PU), Transform Unit (Cu) The coding unit is similar to the concept of macroblocks in the H.264 / AVC. For the encoding process, the prediction unit is a predicted basic unit, and the transform unit is a basic unit for transforming and quantization. The separation of these three units makes the transformation, predicts, and encoding the various processing links more flexible, and also facilitates the division of each link to more in line with the texture characteristics of the video image, facilitating the completion of each unit more optimized. 2. Flexible block structure ---- RQT (Residual Quad-Tree Transform) RQT is an adaptive transformation technology that extends and extension of the ADAPTIVE BLOCK-SIZE TRANSFORM technology in H.264 / AVC. For interframe encoding, it allows the size of the transform block to adaptive adjustments according to the size of the motion compensation block; for intra coding, it allows the size of the transform block to adaptive according to the characteristics of the intra predicted residual. adjust. Big block transformations can provide better energy concentrations with respect to small blocks, and can save more image details after quantification, but on the other hand, there will be more ringing after quantification. effect. Therefore, according to the characteristics of the current block signal, the adaptive selection shift block size, as shown in FIG. 2, the excellent energy concentration, the degree reservation, and the rings effect of the image can be obtained. Figure 2 flexible blockSchematic 3, Sample Adaptive Offset) SAO is in the codeca, after DEBLOCK, by the classification of the reconstructed image, add an offset to each type of image pixel value, reducing the purpose of reducing distortion, thereby increasing the compression ratio, reducing the code stream. After SAO, the average can reduce the code stream of 2% to 6%, while the performance consumption of the encoder and decoder increases by about 2%. 4, Adaptive Loop Filter) The ALF is used to restore the reconstructed image after the DEBLOCK and SAO are in the DEBLOCK and SAO, and the minimum difference (MSE) is minimized between the reconstructed image and the original image. The coefficient of ALF is to apply ALF in frame-level computing and transmission, or may perform ALF based on blocks or quadtree, and if it is based on part of the ALF, it is necessary to pass indicator area information. Additional information. 5, parallelization design The current chip architecture has gradually developed from single nuclear performance, so in order to adapt to a very high degree of chip implementation, HEVC / H265 introduces many parallel operations, mainly including the following aspects: (1) TILE As shown in Figure 3, the image is divided into some rows and columns with vertical and horizontal boundaries, divided into a TILE, each TILE contains the entire number of LCU (Largest Coding Unit), and the tile can be independent of each other. To achieve parallel processing: Figure 3 Tile schematic diagram (2) Entropy Slice Entropy Slice allows you to separately divide multiple Entropy Slices internally, each Entropy Slice can be independently encoded and decoded, thereby improving the parallel processing capability of the codec: Figure 4 Each SLICE can be divided into multiple Entropy Slice (3) WPP (Wavefront Parallel Processing) The second LCU processing of the previous line is completed, that is, initialize the entropy encoding (CABAC) probability state parameters of the current row, as shown in Figure 5. Therefore, only the second LCU codec is only required, you can start the codec of the current line to improve the parallel processing capability of the codec: Figure 5 WPP diagram 6. Improvement in H.264 Algorithm complexity relative to H.264, H.265 has greatly improved, with this better compression performance. H.265 has made great improvements in many characteristics, as shown in Table 2: Be Table 2 H.264 and H.265 Key Characteristics Comparison Third, HEVC (H.265) technology application prospects The H.265 standard is developed based on the H.264 standard, combined with the mainstream position of the H.264 in the field of video applications, can foresee the H.265 protocol in the future broad development prospects. Some mainstream television organizations in the world and media operators have chosen H.264 as a media format standard, and some major codec equipment manufacturers have also actively participate in the study of H.265 standards. Huawei is the main REPORTER (surveyingor) and Editor (editor) of the ITU-T video standard. As a member of the International Telecommunications Union (ITU-T), Huawei is led and participated in a number of national standards and industries and corporate standards. During the H.265 protocol development, Huawei submitted a number of related proposals, recommendations, and provided a very typical application scenario test sequence to obtain high recognition and acceptance of ITU-T. Huawei provides the chinaspeed sequence has been adopted as a standard test sequence as Class F. As the chip processing capacity is getting stronger, the influencing factors of algorithm complexity on the application are getting smaller. On the contrary, in real-time communication applications and IPTV applications, the increase in business continuous expansion and demand increases the limited bandwidth resources become a bottleneck, high compression rate coding is a effective technical means to solve this problem, which is H.265 It has laid a solid foundation based on IP-based applications. At present, many telecom operators use H.264 standards as their media format, and many manufacturers have introduced H.264 standard set-top boxes and video conferencing solutions based on H.264 standards. Huawei is a world-leading telecom solution provider. It is the largest video conferencing research and development agency in China. Since China has officially launched the ViewPoint series video conferencing products, there have been five generations of video conferencing products, more than 600 in the field of video communications. The patent is accepted, including more than 100 international patents. Huawei is able to provide a full range of video conferencing products, including the Zhimi video conferencing system, HD video conferencing system, standard clearance system, and IPTV-based solutions. According to Frost & Sullivan Consultation Report, 2011 Huawei video conferencing solution market share the top three in the world, the market share of Zhizhen is the second. Huawei as a first echelon company in studying HEVC, paying close attention to the development of H.265 standards and will take the lead in the introduction of H.265 related video products. Fourth, conclude HEVC (H.265) standards are expected to issue a formal version in February 2013, due to its great improvement in compression efficiency, parallel processing capabilities, and network adaptability, its development and application must push video codec the theory and application To a new height. Five, reference 1. Gary J. Sullivan and Jens-Rainer Ohm, "" Recent developments in standardization of high efficiency video coding (HEVC) "", SPIE Applications of Digital Image Processing XXXIII, Andrew G. Tescher (editor), Proceedings of SPIE Volume 7798 , PAPER NUMBER 7798-30, August, 2010. 2. http://phenix.int-evry.fr/jct 3. On Residual Quad-Tree Coding in Hevc, Yih Han Tan Chuohao Yeo, Hui Li Tan, ZHENGGUO Li, 978-1-4577-1434-4 / 11 © 2011 IEEE 4. Upgrade from H.264 to H.265, Liu Guoliang, Railway Communication Signal Engineering Technology (RSCE) June 2011, Volume 8 No. 3 5. High EffiCiency Video Coding (HEVC) Text Specification Draft 6, JCTVC-H1003 6. Chen Qing.265 Standards and Development Application Trends [J]. Chinese Multimedia Communication, 2008 (10): 12-15. Patent "double-edged sword" H.265 standard does not charge the most reliable? Not all people and all markets are the same, especially for high-end technologies, a new technology is born in a long time, and the technology needs to keep it while people adapt to new technologies. Adjustments to achieve the most satisfactory level. As everyone used to use high-definition monitoring from knowing the network to use HD monitoring, H.265 has something to say when the video compression technology standard is used. It is well known that the most widely used compression agreement in the video field is H.264 protocol. With the continuous broadening of video sectors, H.264 is about to upgrade to H.265, however, the problem occurs This new compression standard. A new standard will inevitably have patent rights, then after reference, H.265 will become a topic. Patent "double-edged sword" H.265 standard does not charge the most reliable? H.265 payment or no H.264 For video compression criteria, there is a lot before H.264, but when people's visual effect must be satisfied after 1080p HD, natural H.264 has become the protagonist. H.265 Do not charge for the "Face" "" "Face" ", since H.264 is a movie format composed of a number of patents, although the patent rights All organizations MPEGLA have previously been allowed to authorize H. 264 is provided to consumers, but it is still a doubt in the future. At present, if there is a new standard, there is a certain risk, if H.264 is still free, if H.265 charges seem to have an impact on market promotion. H.265 is better than H.264 charge? In the big security market, H.264 appeared such that H.264 can reduce the rate of 50% higher than H.263 at the same rate. That is, if the user wants to experience high quality video services, the bandwidth is easily realized. H.264 not only helps save huge expenses, but also improve resource efficiency, while making video conferencing services to commercial quality have more potential customers. H.265 To reflect in a video conference, the technology must be better than H.264. H.264 is actually a highly compressed digital video codec standard, and H.265 and H.264 come from the same expert group, which extends on the basis of this technology. At present, H.265 is only applied to commercial fields, and it is almost rarely known in the fields common. The new H.265 video standard has a significant improvement in the data transfer and the code flow efficiency. H.263 to H.264 increased by 50%, while H.264 to H.265 will increase by 67%. According to Ms. Turkwei, the engineering staff of the Telecommunications Institute of Industry and Information Technology, said that the resolution of the network transport stream is getting bigger and bigger, and the H.265 can provide similar to the bandwidth requirements. A smaller code rate under quality. Perhaps the bandwidth requirements will be reduced to 1/3 under the same image quality. In the future, in the video standard, although H.264 has not charged, it seems to charge and reasonable factors in the technical level of H.265. Similarly, H.265 still faces two difficulties in the market, one is the unique innovation of this patent, and the other is the popularity of the market. It seems that we can see from the following picture, H.264 current usage will be given H.265 brings a lot of pressure. H.265 encoding damage to video Unlike the HD-SDI non-compressed video image, the compressed video image is more or less to damage the image, especially during the network transmission, but also the phenomenon of packet loss. Objectively, as long as the video image is compressed, there will be damage, of course, it is difficult to escape this shortage in high efficiency compression. From an objective situation, video coding damage mainly has three major categories: encoding standard, IP network, error-prane communication, meticulously, to image blur, noise, data packet loss, delay, jitter, and wireless channel transmission Distortion is inevitable. Although H.265 can really achieve multiple HDs of H.264, some video loss is calculated by data, and the naked eye is high and clear. From the current video conference of the big security market, under the continuous demand of high-definition picture quality, high compression standards can be able to further promote the market, but only cost or the most concerned topic. The ideal price is the final product flows to the market. H.265 Application Prospect For H.265 high compression criteria, there is less figure with HD video. Taking the big security market as an example, HD video conference, 1080p video conference has become the mainstream of the market. According to Cheese Engineers, the current demand and usage of HD video conferencing is growing at a rate of up to 30% to 40% based on the survey data of the video conference market. In addition to the enterprise level, HD online video and HD TV can also use the new agreement with H.265. Youku Potato, Qiyi, LeTV, etc. are all the favorite of netizens. H.265 standard will be released in 2013 At present, the draft H.265 has been completed. It is expected to release this standard in early 2013. At that time, the formal birth of the standard symbolizes this HD video standard again, from the high-definition high-definition, from HD to ultra HD, future in video conferencing, The video surveillance market will be well promoted and used. Of course, if the benefits of this patent are guaranteed, the H.265 that does not charge is the most reliable. references http://tech.qq.com/a/20130126/000058.htm "