H.265 is the latest standard codec used worldwide for the creation, playback, and transmission of video footage in popular video transmission channels.
The most used codec in CCTV until some time ago was the H.264 / MPEG-4 Part 10 (or AVC) born in 2005.
The latter standard was launched in 2013, thanks to agreements between the various international organizations (ISO / IEC JTC 1 / SC 29 / WG 11 / Moving Picture Experts Group (MPEG) and ITU-T SG16 / Q.6 Video Coding Experts Group - VCEG). In 2015, they were finally issued with a format extensions of this standard.
Today, this compression, allows playback of movies coming up all'8K - Ultra HDTV (and including 4K - Ultra HD) resolutions up to 8192 × 4320.
By comparison with the H.264, the most obvious improvement is the following:
Having an equal video quality, the size of the compressed video files in H.265 is half of all'H.264 (or half the bit rate)
In these evaluations, reference is made to the bit-rate. This value represents the speed of the video stream in terms of bits (million bits per second or Mbps). Typically more this value is high and the image is of quality and the greater the space (in terms of MByte) from the video file.
In fact, over the years, the development of the codec (compression) resulted in a reduction of the bit-rate. For example, at a resolution of 352 × 288 (eg a webcam dated) with 8bit color resolution and a frame rate (images per second) of 24 per second, the resulting bit-rate was to 18,55Mbps. A movie than a minute occupied 139MB. With the development of the MPEG-1 (CODEC compression) the bit-rate passed to 1,73Mbps (in video quality equal) occupying 12MB. With the MPEG-4 (CODEC compression), it introduced the technology dell'interframe (compression technology based on the description of the changes between one frame and the next, suitable for movies in which there is little action). In this last case the compression ratio varied instantaneously depending on the type of scene maintaining constant the level of image quality and a reduction of the dimensions of the video.
Consequences in the field of CCTV
- Optimal image quality
- Ability to switch to 4K resolutions.
- On a comparable resolutions, less space occupied by images in the Hard disk.
- DSP cameras with more complex.
- Dvr with more complex processors.