How to choose camera, video camera, microphone for video conference
One, the choice of camera
The lens is an important part of the camera, and the photosensitive element of the camera can be divided into CCD and CMOS. CCD (Charge Coupled Device, charge coupled device) is a high-end technology component used in photography and imaging, and CMOS (Complementary Metal-Oxide Semiconductor, metal oxide semiconductor device) is used in products with lower image quality. Its advantages are The manufacturing cost is lower than that of CCD, and the power consumption is much lower. This is the reason why many products adopting USB interface in the market do not need external power supply. At present, the size of the CCD element is mostly 1/3 inch or 1/4 inch. Under the same resolution, it is better to choose a larger element size.
Pixel value is an important indicator that affects the quality of a camera, and it is also a more important indicator for judging its pros and cons. The pixel value of the early products is generally around 100,000. Due to the low technical content, it is now on the verge of being eliminated. The pixel value of mainstream products is generally around 350,000. It is not necessary to blindly consider the pixel value. Because the higher the pixel value, the higher the ability of the product to parse the image. In this way, when the camera is working, the computer's ability to process data is also required, otherwise it will cause the delay of the picture, which will affect the video. Transmission of the meeting.
Resolution is the ability of the camera to analyze and discern images. Of course, it is directly related to the quality of CCD/CMOS. Generally, it can be divided into two types: camera resolution and video resolution, namely, the resolution when capturing static images and the resolution when capturing dynamic images. In practical applications of video conferencing, the camera resolution is generally higher than the video resolution. The types of resolutions that the cameras on the market can give are also different, so you should pay attention when purchasing. Some resolution marks refer to the interpolation resolution that these products can achieve with software, but they are distinguished from hardware. Compared with the rate, there is still a certain gap.
4. Transmission speed
The video capture capability of the camera is one of the core functions of the camera. At present, the video capture of the camera is realized by software, so the processing power of the CPU is also higher, because the requirements for the picture are directly proportional to the capture capability. At present, the maximum resolution of the picture captured by a general camera is 640×480. Under this resolution, no camera can achieve a 30 frame/second capture effect, so the picture will be jittery. It is more realistic that the combination of hardware and software at 320×240 resolution may reach the standard rate of capture index, so for the complete video capture speed, it is only a theoretical index. Therefore, users should choose the appropriate product according to their needs to achieve the desired effect of the video conference.
High data transfer volume, without a USB interface, is incapable. USB port products have always been plug and play, easy to use, and are happy to be accepted by the majority of computer users. The use of the USB interface not only makes the hardware detection and installation of the camera more convenient, but more importantly, because the high speed of USB data transmission determines the application of the camera, it better breaks the bottleneck of the large amount of data transmission of image files, and makes the computer receive more data. Quickly, make the playing effect of dynamic images smoother and smoother.
Second, the choice of camera
The camera needs to be used with a video capture card. The camera is the core equipment of the video conference system. It is very important to choose a reasonable choice according to user requirements. Now the system generally uses CCD camera (Charge Coupled Device), that is, charge coupled device, because compared with vacuum tube camera, it has small size and light weight; low inertia; high sensitivity; good image uniformity; good impact resistance; long life, etc. advantage.
In meeting room-level applications, in order to obtain better video effects, cameras are generally used as video sources. For video conferencing applications, cameras can be divided into two categories, one is a fixed type, and the other is a mobile type. The fixed type is fixed on the desktop or bracket, and the video image is obtained by the movement of the lens. The mobile type is also called portable, and users can choose the input of video information as they wish.
Three, meeting microphone selection
The conference microphone is a very important equipment in the deployment of the conference room, which has a significant effect on the sound effect of the entire system.
The choice of microphone mainly starts from four aspects. Firstly, the frequency response should be about 150Hz～10KHz, this range basically includes human voice and general musical instrument sound; secondly, the sensitivity should not be too high, too high sensitivity is easy to produce howling or the sound fluctuates loudly and easily, and it is easy to damage Sound box, so the sensitivity is stable; third, the impedance is high and low, and the high-impedance microphone has high sensitivity and is susceptible to external signal interference. Finally, it is necessary to choose a directional microphone, because the non-directional microphone has poor anti-interference ability and is easy to mix into other sound sources. This kind of microphone must be used in conjunction with an echo canceller.