Differences between encoding technology

HI @Rumana

Above mentioned codecs compare distinct elements of a video frame in order to identify those that are redundant in subsequent frames. These parts are replaced by a brief description of the original pixels. The capacity to increase the size of these sections into bigger or smaller blocks, called coding tree units (CTU) in HEVC/H.265, distinguishes HEVC/H.265 from H.264. The pattern CTU sizes can range from 44 to 6464, however H.264 only allows for a block size of 1616. (CTU is a particular feature of HEVC). Improved CTU segmentation, motion compensation, and spatial prediction necessitate much greater signal processing capabilities for video compression but have a far smaller influence on the amount of computation required for decompression. Another significant advancement in HEVC/H.265, motion-compensated prediction, refers to blocks of pixels in the same frame (intra prediction) or in another frame (extra prediction) (inter prediction).

As previously said, CTU is one of the most important HEVC coding tools. Aside from that, the codec uses parallel processing computing techniques to speed things up even more, and it supports advanced extensions like AVX/AVX2 and FMA3/FMA4. Individual rectangular sections that divide the image are self-contained and can be processed in simultaneously. Furthermore, HEVC features a feature that H.264 lacks: Wave front Parallel Processing (WPP), a type of decision tree that allows for more efficient and effective compression.

Several other coding algorithms used in H.264 are carried over into this new codec, however with some minor but significant alterations. The Context-adaptive binary arithmetic coding (CABAC), a lossless data compression entropy coding, is kept in HEVC/H.265 albeit in a slightly updated version. Another component that has seen substantial improvements in comparison to H.264 is intra prediction. HEVC specifies 33 directional modes, but H.264 limits them to eight and permits both DC intra and planar prediction. A further improvement is mostly due to Adaptive Motion Vector Prediction, the newest method for inter-prediction, which utilizes picture information in a more compact manner.

HEVC/H.265 includes a dexterous coding technique that encodes motion vectors with significantly greater precision and minimum residual errors, as well as better visual quality at cheap storage and bandwidth. Aside from the industry-leading inter-prediction approach, this new codec also features an upgraded deblocking filter and sample adaptive offset to minimize artifacts even further.

I hope my answer will helpful for you.

Source:

https://www.a1securitycameras.com/security-camera-technologies/hikvisions-new-storage-saver-h.265-encoding-technology/

https://www.boxcast.com/blog/hevc-h.265-vs.-h.264-avc-whats-the-difference

https://www.unifore.net/ip-video-surveillance/difference-between-h-265-and-h-265-video-compression.html

H.265 is more advanced than H.264 in several ways. The main difference is that HEVC allows for further reduced file size, and therefore reduced required bandwidth, of your live video streams.

Unlike H.264 macroblocks, H.265 processes information in what’s called coding tree units (CTUs). Whereas macroblocks can span 4x4 to 16x16 block sizes, CTUs can process as many as 64x64 blocks, giving it the ability to compress information more efficiently.

In addition to the larger CTU sizes, HEVC also has better motion compensation and spatial prediction than AVC does. This means that HEVC requires more advanced hardware, such as the Huawei Ideahub, to be able to compress the data. Fortunately, however, it also means that viewers with H.265 compatible devices will require less bandwidth and processing power to decompress that data and watch a high-quality stream. This also enables the streaming of 4K video over common network speeds.

Because H.265 compresses your data so much more efficiently, using it as your video compression tool will drop your bandwidth and storage requirements by roughly 50%.

About H.264 and H.265, you can check this topic:

https://forum.huawei.com/enterprise/en/h-265-vs-h-264/thread/689985-881

About H.265+:

Haven't heard of H.265+ yet, I think there will be in the future. It must be better than H.265 to some extent.

Comparison: H.265 and H.264

1. Transmission bit rate
Due to the optimization of the algorithm, H264 can transmit SD digital images at a speed lower than 1 Mbit/s. H.265 can transmit 720p (resolution: 1280 x 720) HD audio and video at a transmission speed of 1 Mbit/s to 2 Mbit/s.

H.265 can transmit high-quality network videos with limited bandwidth. Only half the original bandwidth can be used to play videos of the same quality, allowing 1080p full HD videos to be played online. The H.265 standard also supports 4K and 8K ultra-HD video, enabling network video to keep pace with high-resolution displays.

2. Compression rate and bit rate

H.264 is a high-performance video encoding and decoding technology. It has a high compression ratio. Under the same image quality, the compression ratio of H.264 is more than twice that of MPEG-2 and 1.5 to 2 times that of MPEG-4. With a low bit rate, H.264 greatly reduces the download time and data traffic charges, and reduces costs.

It is worth mentioning that H.264 has high compression ratio and high-quality and smooth images. As a result, H.264-encoded video surveillance requires less bandwidth, is faster, and is more cost-effective. Just like a video of the same quality and picture quality, H.264 can compress a video file by half.

Compared with H.264, H.265 has a better compression efficiency. Compared with H.264, H.265 reduces transmission by half and storage by half.

3. Video quality

H.265 introduces a deblocking filter function, which smoothes edge areas as much as possible and establishes data dependency between blocks, thereby improving the overall image quality. If the resolution is high enough, the pores on the face of the video character can be seen clearly. Therefore, the H.265 image quality is more refined.

H.265+ is more optimized based on H.265 in encoding, noise and bit rate, making it easier for video surveillance to transmit 4K images.