The difference between video capture card in the field of video conference and surveillance
Video capture cards are an important component of video surveillance. In addition, video capture cards are also widely used in DV capture, video conference, webcast, video recording, and video live broadcast systems. The following editor from Beijing Meifeite tells you the difference between video capture cards in the field of video conferencing and surveillance.
First we need to understand the technical principles of video surveillance and video conferencing. The front-end acquisition of the monitoring system is collected by analog signals. For example, the surveillance camera gun and dome camera are used to collect analog signals. The collected data is compressed and stored on the hard disk. The PTZ used by the video conference system The camera also collects analog signals and then transmits the data to other clients through encoding. The two methods are roughly the same, but why can't the monitoring equipment be used as the front-end acquisition equipment of the video conference system? The main reason is that the connected video capture card and interface are different. The capture card used in video conference and the capture card used for monitoring are quite different, so we need to understand the classification of the capture card.
Currently, video capture cards can be divided into VGA capture cards, HDMI capture cards, DVI capture cards, SDI capture cards, analog AV capture cards, 1394 capture cards, S terminal capture cards, etc. according to the interface, so the capture card used for monitoring is video One of the capture cards, which generally has multiple data interfaces, can capture multiple videos at the same time; and the capture cards we usually use for video conferences are mainly streaming media capture cards, which generally can only capture One channel of image data, its analog signal is converted to digital signal, without compression operation, so the video conference capture card is also commonly called video soft compression card, and the data of the monitoring card is compressed, so the monitoring capture card is also called video hard compression card.
The difference between monitoring and video conferencing equipment is that the interfaces are not the same except for the capture card. The monitoring equipment generally uses a BNC interface to connect the monitoring equipment and the capture card, while the video conference equipment is generally implemented through AV or HDMI interfaces. The PTZ camera is connected to the capture card, so the monitoring equipment cannot be connected to the video soft compression card used for video conference. The same PTZ camera for video conference cannot be connected to the monitoring card.
In addition, monitoring video capture cards and video conference capture cards are also different. Video conference capture cards have higher requirements, such as video clarity, scalability, compatibility, etc. Some even need to redevelop functions. For example, in a multi-channel video conference, a multi-channel monitoring and acquisition card cannot be compatible with multiple channels simultaneously, while a video conference acquisition card can be compatible with multiple channels simultaneously. In addition, in video conferences, there are very high requirements for the definition of video, and audio also needs to be synchronized with video capture.
In summary, the difference between video capture cards in the field of video conferencing and monitoring is still relatively large. In the application, you must choose according to your actual situation.