What is 4kh.265 decoding? what's the function? Want to understand the meaning of TV H.265 decoding, then you must first understand what is H.265.
Quick description:
H.265 is a new video encoding in recent years, which greatly reduces the capacity of the video while ensuring video quality. Before this, the H.264 encoded, this code has been accompanied by us for more than a decade, you usually watch, most of the video is mostly this code.
Example: H.264 encoding the short film 20g, suppressed into H.265 encoding, can become about 10g, so it greatly saves video space, especially in the age of 4K, just a 4K movie will hundreds g, so you must Have better coding to support, in order to promote 4K high-speed development.
H.265 decoding:
Because this is a new video coding technology that requires hardware support.
Deep understanding:
Before discussing H.265, we may wish to first understand H.264.
H.264, also known as MPEG-4AVC (AdvanceDvideoCodec, Advanced Video Coding) is a video compression standard, and is also a recorded, compression, 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 TV terrestrial 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 recognized by people.
The encoding architecture of H.265 / HEVC is similar to the architecture of H.264 / AVC, mainly including: 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.
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. For example, the amount of information in the amount of information (color change is not obvious, such as the red portion of the body and the gray portion of the ground) is large, and the codeword is less, and more than the place (tire) ) The divided macroblock is much smaller, and the encoded codeword is more, which is equivalent to the encoding of the image, thereby reducing the overall code rate, and the encoding efficiency is correspondingly improved. At the same time, the intra prediction mode of H.265 supports 33 directions (H.264 only supports only 8), and provides better motion compensation processing and vector prediction methods.
Repeated quality comparison tests have shown that under the same image quality, video size encoded by H.265 will be reduced by approximately 39-44% compared to H.264. Different data will also have corresponding changes due to the measurement of quality control. 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.
This article is transferred from D1NET (reproduced)
Related resources: H.265HEVC principle, standard and implementation - Code Documentary Resources
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