When shopping for security systems (recorders or cameras) you’ll definitely stumble upon H.264 and H.265. What those terms mean? Many people might associate H264 to security camera system. Many of the DVR and NVR we sell have H264 printed on the box or displayed at the system’s initial boot. But in reality, many of the higher quality videos, streamed online, uses H264 compression. H264 is the method of video compression that compares the motion in encoded image vs the stationary objects.
H264, Advanced Video Encoding, provides a good video quality at considerable lower bit rate than previous standard video protocols: MPEG-2, H263, and MPEG-4 part 2. There two things needed for H264 to work appropriately. 1) the devices capturing the video must be able to properly encode videos. 2) the playback device must be able to also decode the H264 videos back to playable video format. Since there is no standardized format for H264 and many different companies hold different patents, each security camera system might encode their H264 in various ways. That is why, each security system has generic files for their H264 compress videos.
H265 or High Efficient Video Coding, is new standard video compression that provides even more improvement than H264. H264 provides improved bit reduction of 57% at 1080p and 64% of UHD or 4K compare to H264. Since all our devices, smart phones to smart TVs, are recording or displaying at much higher resolution, it is even more important that we have HEVC compression. Many of the popular streaming website have encoded all their videos to HEVC or H265.
|Names||MPEG-H, HEVC, Part 2||MPEG 4 Part 10, AVC|
|Progression||Successor to H.264/AVC||Successor to MPEG-2 Part|
|Key improvement||*40-50% bit rate reduction compared with H.264 at the same visual quality. *It is likely to implement Ultra HD, 2K, 4K for Broadcast and Online (OTT). *New standard use on CCTV systems.||*40-50% bit rate reduction compared with MPEG-2 Part. *Available to deliver HD sources for Broadcast and Online.|
|Support up to 8K||Yes.||No. Supports up to 4K|
|Support up to 300 fps||Yes||No. support up to 59.94 fps only.|
Both codecs work by comparing different parts of a video frame in order to find the ones that are redundant within the subsequent frames. These areas are replaced with a short information, describing the original pixels. What differs HEVC/H.265 from H.264 is the ability to expand the size of these areas into bigger or smaller blocks, called coding tree units (CTU) in the HEVC/H.265. The pattern CTU sizes can be from 4×4 to 64×64, whilst H.264 only allows a maximum block-size of 16×16 (CTU is particular feature of HEVC). An improved CTU segmentation, as well as a better motion compensation and spatial prediction require much more signal processing capability for video compression, but has a significantly less impact on the amount of computation needed for decompression. Motion compensated prediction, another great progress in HEVC/H.265, references blocks of pixels to another area in the same frame (intra prediction) or in another frame (inter prediction).
To conclude this article, we come to the most important question: What’s recommended for the CCTV systems? If your security system supports H.265 than that’ what you should use. For the same hard drive you’ll get more days of recordings compared to the H.264 compression. Make sure the camera and the recorder support H.265.