Programming of television programs

That is, electronic editing based on magnetic tape. Its fundamental characteristic is: the search for material, recording must be carried out in chronological order, the need to repeatedly roll back and forth in order to find material, so more troublesome, time-consuming, easy to damage the tape, the loss of image quality, and to limit the idea of artistic creation, the need for more people to operate and to coordinate the matching of the equipment. It has gone through three stages of development:

1, physical editing: by the United States in 1956, Ampex produced the first two-inch VCR began, but the damage to the tape is permanent, and editing point is not precise.

2, electronic editing: after 1961, the emergence of one-to-one editing system, but the accuracy is still not high enough.

3, time code editing: developed by the United States in 1967 by the Electronic Engineering Corporation, the application of pre-roll, more accurate, but the loss of signals on the tape caused by multiple copies can not be completely avoided. English Nonlinear Editing System is the use of digital storage media for digital audio and video editing post-production system. Has the following characteristics:

1, is supported by computer technology, the full use of digital processing technology research results, with low cost, high efficiency, high quality, the effect of infinite transformation into the field of radio and television, the traditional linear editing process has caused a great impact.

2, the so-called non-linear, that is, the ability to randomly access any material, not subject to the limitations of the material storage time, and a set of non-linear editing system can be achieved linear editing equipment for almost all the functions: computer as a platform with a dedicated image card, video card, sound card, with some special cards (such as subtitle card, stunt card, etc.) and high-speed hard disk (SCSI), to the software as a control center for the production of TV programs.

3, the production process: first of all, the audio and video signals from the VCR and other sources through the video card, sound card acquisition and analog-to-digital (A/D) conversion, and the use of hardware, such as compression card compression in real time, the compressed data stream is stored in the high-speed hard disk. Next, the use of editing software to process the material to make a film, and finally the high-speed hard disk will be sent to the corresponding board for digital decompression and (D / A) conversion, reduced to analog audio and video signals recorded to tape.