Laser video disc-what is ——VCD?

VCD, commonly known as optical disc, appeared to replace LD (laser recording disc, called laser disc in Hong Kong and Taiwan, disc diameter 12 inch). Like CD, LD uses laser technology to store information, but the difference is that it is specially used to store video, and the method used for signal conversion and playback before storage is also different from CD. Because of the high price and large size of LD, VCD first appeared in China to replace it. VCD, like CD, has a diameter of 5 inches, and can play full-screen, full-motion images and stereo music for 74 minutes. It follows the MPEG- 1 specification, although the picture quality is not as good as LD, but the price is much lower than LD. So in China, where the income is not high, it was quickly accepted by consumers and became the best-selling household appliances in less than three years.

Although VCD DVD player and VCR have little difference in appearance and similar functions, they are different products. The main difference is that the video recorder has a "recordable" function. Because the video recorder is not only an audio-visual playback device, but also an audio-visual reproduction device, and the VCD player is only an audio-visual playback device. Video recorders can record programs from various sources, such as TV, CD or other videos, while VCD players can't. In addition, video can play the programs shot by the camera, especially in the case of the increasing popularity of small household cameras, playing the programs shot by yourself will add a lot of fun to people. In addition, the image quality of video recorders is constantly improving. At present, the image definition of VHS video recorders is above 240 lines, and some have reached 260 lines, while the resolution of general VCD players is only 230 lines. Therefore, in a period of time, VCD players will coexist with video recorders, each with its own uses.

Not long ago, VCD (China Video Disc) appeared in China, which is a new product developed to improve the quality of VCD. Technically, CVD uses the same MPEG-II specification as DVD, and the resolution is between 280-352 lines. The picture quality can completely reach the resolution limit that the existing color TV can display, and the picture quality is excellent, so that you can enjoy high-definition pictures on ordinary color TV. Although its picture quality is not as good as DVD, it is better than VCD. Although its price is more expensive than VCD, it is much lower than DVD, and the requirements for housing conditions and audio-visual configuration are not as high as DVD, which is more suitable for the economic level of consumers in China. This will be a realistic choice before the transition to DVD.