H.264, H.265 and H.265 + video codecs. Pros and cons
The first versions of H.264 video compression codecs appeared in 2013. Today, the Н.265 format has confidently entered the video surveillance market and dictates its own terms. Many manufacturers produce equipment that supports this video compression format.
The H.264 compression format, unlike previous MJPEG and MPEG-4 codecs, enables you to efficiently solve the problem of streaming a large number of high-definition video streams.
Using H.264 in IP video surveillance systems provides high image quality with less data, requires less network bandwidth, and fewer hard drives to store video files. However, there is also a downside of fat. Using H.264 places heavy loads on IT equipment.
To increase the efficiency of the use of computing resources, developers apply various methods. For example, transfer part of the operations to the video card. Thanks to this, the video card can take care of part of the decoding calculations. The use of this feature provided a reduction in processor load up to two times, and the possibility of using processors of lower power, and therefore the cost.
Transferring decoding operations to a video card also allows you to save not only on the server, but also on the client side of the video surveillance system. To use this function, in the configuration of the client part of the software, you must specify where to perform the processing: on the central processor or on the video card.
To reduce the load on IT equipment, video analysis technology of compressed video streams from IP cameras without their complete decoding is also used. The use of this technology leads to an increase in data processing speed, thereby reducing the load on the central processor. In addition, the decrease can reach an average of 4 times.
Thanks to this, it is possible to connect 4 times more cameras to one server. Another option to save is the use of less powerful processors and, therefore, more budgetary, and a decrease in the cost of the server equipment.
Another disadvantage of the H.264 codec is that most web and mobile clients for video surveillance systems do not support this format and, to receive a video image, a procedure is required to transcode the video stream into MJPEG. Such an operation is resource intensive and places additional loads on computing resources.
H.264 processing is possible with sufficiently powerful computing resources of a mobile device. If resources are insufficient, the video stream is automatically switched to the MJPEG format. And the user himself can independently choose the format of the video transmission.
As you can see, the H.264 codec used for video surveillance has many pros and cons. However, a heavy load on computing resources often nullifies all benefits.
The new H.265 format supports even more uploads. It uses stronger and more advanced video compression algorithms in its work. With the same visual quality, the new H.265 codec represents an approximately double reduction in file size compared to its H.264 predecessor. This saves a lot of space on the disk space of video recorders and servers. And half the bit rate reduces traffic on video transmission networks.
Thanks to more powerful compression mechanisms, the H.265 codec does an excellent job of encoding high and high definition video over 8K UHD (8192 × 4320). In addition, for high-quality video playback at 4K codec resolution, a transmission speed of only 50MB / s is required.
It is important that H.265 compress the video almost without loss, the quality of the compressed video is kept at a high level. Special compression algorithms eliminate artifacts inherent in H.264, such as graininess or blurry edges of moving objects.
But the main advantage of the H.265 codec is that the volume of video processed according to the new standard turned out to be almost 85% lower than when using H.264. However, the H.265 codec requires more powerful elements and processors in the hardware.
Moving towards increasing video compression, the H.265 + codec recently appeared on the market that allows you to reduce the bit rate of video cameras, which in turn reduces the cost of implementation and uses fewer matrices of disk for storing video files.
H.265 + improves the compression ratio through three key technologies: predictive encoding technology, background noise suppression technology.
