What are the main stream and substream of auto focus camera?

The bitstream of the auto focus camera refers to the data flow in unit time after the video image is encoded and compressed, also known as the bitrate, which is the most important part of the picture quality control in video coding. At the same resolution, the smaller the compression ratio, the larger the bit rate of the video image and the higher the picture quality.

The main stream of auto focus camera is used for local storage, and the sub-stream is suitable for image transmission on low bandwidth network. Dual stream uses one high bit rate stream for local HD storage. This is called dual stream technology. The purpose is to solve the quality problem of local storage of surveillance video and network transmission of images.

Auto focus camera dual stream can achieve local and remote transmission of two different bandwidth stream requirements, local transmission can use the main stream, can obtain clearer storage video, remote transmission because of bandwidth limitations, and the use of substream to obtain smooth images and video.

auto focus camera

When a video enters the video recorder, the video recorder can encode the main stream and substream two streams, the main stream is used for local recording, and the substream is used for network transmission. The default is video recorder local access, automatic main stream display. Remote access automatic substream display, so when you remotely monitor access when there is a delay, you can try to reduce the substream to solve.

The main stream of the auto focus camera is generally larger, with high clarity, and occupies a high bandwidth. In the image environment of the main stream, the sub-stream reduces the image format, the clarity is lower than that of the main stream, and the bandwidth is small. The primary stream is generally used for storage, and the substream is used for network transmission. The primary stream is stored locally, while the substream is suitable for image transmission over low-bandwidth networks.

The purpose of this is to reduce the bit rate of the substream if the network condition is not very good when we use the substream preview (the picture quality will be reduced with the decrease of the bit rate) to improve the fluency of network browsing without changing the recording effect of the local video.