Our recent new products can support H.265. More and more input video signals use H.265 encoding standards, and the H.264 encoding is gradually reduced, why will H.265 will pop? What is the difference between H.264 and H.265? Today we will introduce all kinds of construction technicians:
What is H.265
H.265 is a new video coding standard established after ITU-TVCEG followed by ITU-TVCEG. The H.265 standard surrounds the existing video coding standard H.264, reserves the original technologies, and improves some related technologies. New technology uses advanced technology to improve the relationship between code stream, coding quality, delay and algorithm complexity, reaching optimization settings.
Specific research contents include: increasing compression efficiency, improving robustness and error recovery capabilities, reducing real-time delays, reducing channel acquisition time and random access delay, reducing complexity, etc. Since the algorithm optimization, the H265 can be achieved at a speed of less than 1 Mbps, and H265 can realize the transfer of 720P (resolution 1280 * 720) to transmit 720P (resolution 1280 * 720) to transmit the transmission speed of 1 to 2 mbps.
The H.265 is intended to transmit higher quality network videos, only the original half band width can play the same quality video. This also means that our smartphones, tablets and other mobile devices will be able to play directly online 1080P full HD video. The H.265 standard also supports 4K (4096 × 2160) and 8K (8192 × 4320) ultra HD video. It can be said that the H.265 standard allows network video to keep up with "high resolution" footsteps.
What is H.264
H.264, is also the top of the MPEG-4, which is the height raised by the ITU-T video coding expert group (VCEG) and ISO / IEC Dynamic Image Expert Group (MPEG) combined with a combined video group (JVT, JointVideoTeam) Compressed digital video codec standard. This standard is generally referred to as H.264 / AVC (or AVC / H.264 or H.264 / MPEG-4AVC or MPEG-4 / H.264AVC) to express its two developers.
The maximum advantage of H.264 is to have a high data compression ratio. Under the conditions of the same image quality, the compression ratio of H.264 is 2 times the MPEG-2, which is 1.5 to 2 times the MPEG-4.
For example, if the size of the original file is 88GB, it is 3.5GB after compressing the MPEG-2 compression standard, and the compression ratio is 25: 1, and the compression ratio is compressed by the compression standard to 879MB, from 88GB to 879MB, The compression ratio of H.264 is an amazing 102: 1.
Lowbitrate plays an important role in the high compression ratio of H.264, compared to compression technology such as MPEG-2 and MPEG-4ASP, the H.264 compression technology will greatly save users' download time and data traffic. Toll. It is particularly worth mentioning that H.264 also has a high quality image while having a high compression ratio, as in this way, after the H.264 compressed video data, less bandwidth required in the network transmission process, It is also more economical.
H.265 is different from H.264
Before discussing H.265, we may wish to first understand H.264. H.264 is also known as MPEG-4AVC (AdvancedVideoCoding, Advanced Video Coding), is a video compression standard, and is also a recorded, compressed and release format that is widely used high-precision video. H.264 is famous for its codec standard for a Blu-ray disc, and all Blu-ray players must be able to decode H.264.
More importantly, because Apple has finally abandoned Adobe's VP6 encoding, I chose H.264. This standard also walked thousands of households with billions of iPad and iPhone, became the current video coding field. Absolute overlord accounts for more than 80% of the share.
H.264 is also widely used in network streaming media data, various high-definition television broadcasts, and satellite TV broadcasts. H.264 has some new features compared to previous coding standards, such as motion compensation, change block size motion compensation, intra predictive coding, etc., H.264 is more than other coding standards by using these new features. High video quality and lower code rates have been widely approved by people.
The encoding architecture of H.265 / HEVC is similar to the architecture of H.264 / AVC, which mainly includes: intra prediction, interprediction, transform, quantization, go to the area Block filter, entropy coding, etc. However, in the HEVC coding architecture, the overall is divided into three basic units, namely, CodingUnit, Cu, predictor, and transformunit, TUs, respectively.
H.265 Why is it better than H.264
More different tools are provided by H.264 / AVC, H.265 / HEVC to reduce the code rate, in the coding unit, the size of each macroblock, MB) in H.264 is fixed 16x16 Pixels, and the coding unit of H.265 can choose from the smallest 8x8 to the maximum 64x64.
Repeated quality comparison tests have shown that under the same image quality, the video code stream encoded by H.265 is reduced by approximately 39-44% compared to H.265 compared to H.264. This data will also have corresponding changes due to differences in quality control measurement. According to the data derived by subjective visual test, the quality of the H.265 encoded video can be approximately even better with the H.264 encoded video in the case of a rate of 51-74%, which is essentially more than expected. The signal to noise ratio (PSNR) is good. These subjective visual tests have covered many disciplines, including psychology and human eye visual characteristics, and video samples are very broad, although they can't be the final conclusion, but this is also very inspiring results.
The current HEVC standard has three modes: Main, Main10 and MainstillPicture. The main model supports 8Bit color depth (ie, 256 chromasings each having a total of 167 million colors). The MAIN10 mode supports 10 bit color depth, which will be used in UHDTVs (UHDTV). The top two will limit the color sampling format to 4: 2: 0. It is expected that the standard will be expanded in 2014, which will support 4: 2: 2 and 4: 4: 4 sampling format (ie, higher color reduction) and multi-view encoding (eg, 3D stereo video coding).
In fact, H.265 and H.264 standards have some overlap in various functions. For example, the HI10P part in the H.264 standard supports 10 bit color deep video. Another part of H.264 (Hi444PP) can also support 4: 4: 4 chrominance sampling and 14-bit deep. In this case, the difference between H.265 and H.264 reflects that the former can use fewer bandwidth to provide the same function, the price is the device computing power: H.265 encoded video requires more computing power To decode. There is already a chip that supports H.265 decoding - the US Broadcom is published in the CES exhibition in January this year, which is a quad-core processor with 28 nano-processes. At the same time, the four 1080p video data streams or resolutions are H.265 encoding ultra HD video of 4096 × 2160.
The birth of the H.265 standard is to transmit higher quality network video under limited bandwidth. For most professionals, the H.265 coding standard is not unfamiliar, which is the video coding standard established after ITU-TVCEG followed by H.264. The H.265 standard is mainly surrounded by the existing video coding standard H.264. In addition to some other technologies, it has increased the relationship between improved code stream, coding quality, delay and algorithm complexity. Related technology. The main contents of H.265 include increasing compression efficiency, improving robustness and error recovery capabilities, reducing real-time delays, reducing channel acquisition time and random access delay, reducing complexity.
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