Video capture card, also called video capture card, can be used to digitize video information and store or play back the digitized information. The video capture card inputs the video data or mixed video and audio data output from analog cameras, video recorders, LD video disk players, TV sets, etc. into the computer, and converts it into digital data that can be discerned by the computer, and then stores it in the computer to become a recognizable data. Edit processed video data files. Most video capture cards can record audio while capturing video information, and can also ensure synchronous storage and synchronous playback.
In addition, many video capture cards also provide hardware compression functions, which have fast capture speed and can achieve full-screen video capture at 30 frames per second. Depending on the compression format, some video files compressed by this type of capture card require corresponding decompression hardware to be played back. These video capture cards are sometimes called compression cards. Using video capture cards, we can convert original video tapes into digital information that can be recognized by computers, and then make them into VCDs; we can also directly obtain video information from cameras and cameras to edit and produce our own video programs.
According to their uses, they can be divided into broadcast-level video capture cards, professional-level video capture cards, and civilian-level video capture cards. Their levels are mainly due to the different quality of the captured images. Broadcast-level video capture cards are characterized by high resolution of captured images and high video signal-to-noise ratio. The disadvantage is that video files require large hard disk space. The amount of data consumed per minute is at least 200MB. It is usually connected to a BetaCam camera/video recorder, so it is mostly used to record programs produced by TV stations. The performance of professional-grade video capture cards is slightly lower than that of broadcast-grade cards. The resolutions are the same, but the compression ratio is slightly larger. The minimum compression ratio is generally within 6:1, and the input and output interfaces are AV composite terminals. With S-Video, this type of product is suitable for advertising companies and multimedia companies to produce programs and multimedia software applications. The dynamic resolution of civilian-grade video capture cards is generally low, and most of them do not have video output functions.
Before purchasing a video capture card (box), everyone should first consider whether their computer is capable of video capture, compression, and storage. Because the amount of standard video and audio data is very large, it requires high CPU, hard disk and other aspects. If there is no compression, the data collected in just one minute may reach hundreds of megabytes. And if your CPU and hard disk cannot keep up with the requirements, you will not be able to perform the capture work, or the effect will be poor (such as severe picture distortion, discontinuity, dropped frames, etc.). So if you want to make a smoother video capture work, A CPU of PIII level or above and a 40G hard drive with at least 7200 rpm are essential.