{"id":56,"date":"2017-04-25T11:32:18","date_gmt":"2017-04-25T16:32:18","guid":{"rendered":"https:\/\/learncctv.com\/?p=56"},"modified":"2021-09-17T13:02:19","modified_gmt":"2021-09-17T18:02:19","slug":"how-cctv-codecs-work","status":"publish","type":"post","link":"https:\/\/learncctv.com\/how-cctv-codecs-work\/","title":{"rendered":"Understand how CCTV codecs work"},"content":{"rendered":"

When the video is generated by a CCTV camera, is necessary to compress it to save bandwidth and storage space<\/span>. The compression is performed by a CCTV codec algorithm such as MJPEG, MPEG-4, H.264 or H.265. In this article I will explain how the main CCTV codecs work. Just keep reading…<\/p>\n

A CCTV codec works just like a standard codec created to reduce the video size by looking for redundant information to eliminating it.<\/p>\n

We can divide the word CODEC into two parts:<\/p>\n

CO<\/span> = Compression<\/p>\n

DEC<\/span> = Decompression<\/p>\n

The side that generates the video will compress it before sending, while the other side that receives it will decompress to display the video correctly in a computer, mobile phone, tablet or other device.<\/p>\n

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In an analog system<\/span>, the DVR <\/span>(Digital Video Recorder) converts the signals from analog to digital and uses an algorithm to compress the video before record it on the Hard Disk (HD) or transmit live to a computer or other device,<\/p>\n

Compression in a system with \ufeff\ufeffAnalog \ufeff\ufeff\ufeff\ufeffcameras \ufeff\ufeffand DVRs<\/span><\/span><\/p>\n

<\/span>\"CCTV<\/span><\/p>\n

The DVR converts from analog to digital and compress the video by using some CCTV codec algorithm that will discard parts of the video information to save as much storage space as possible.<\/p>\n

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Compression in \ufeff\ufeffa \ufeff\ufeff\ufeffsystem \ufeff\ufeff\ufeffwith \ufeff\ufeffIP cameras and NVRs<\/span><\/span><\/p>\n

In an IP CCTV system<\/span>, the camera is in charge of the video digitization and compression, so it sends the video directly to a NVR<\/span> (Network Video Recorder) to be recorded in a Hard Disk (HD),<\/p>\n

<\/span>\"CCTV<\/span><\/p>\n

The NVR receives the videos in digital format to recorded it and transmit to a computer which has a specific monitoring software.<\/p>\n

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But if some information from the digitized video is discarded, part of the quality is lost, right ?<\/p>\n

Yes, but the idea is to discard as much information as possible, with minimal impact to the final quality, and each CCTV codec algorithm works in a different way to accomplish this task.  <\/p>\n

The most common \ufeff\ufeffCCTV \ufeff\ufeff<\/span>CODECs <\/span>are:<\/span><\/span><\/p>\n