Digitales Datenempfangssystem

摘要

In digital video broadcasting, data for standard devices are transmitted in MPEG2 format. In the standard device an MPEG2 decoder decodes the data. An image with 720 x 576 pixels is generated on the screen according to the usual image format in the CCIR601 system. However, the expensive MPEG2 decoder and also a filter are needed, even for a screen with only 320 x 273 pixels, e.g. a 5" display, to filter out the superfluous data. In order to dispense with the expensive MPEG2 decoder and the filter, the bit rate of the data flow received is first reduced by means of a bit rate converter (BRU), the data are decoded and transmitted to one or more displays (D1, ..., Dn) with lower image resolution. Data transmission systems in which a data source transmits data at a higher bit rate or lower compression rate than is needed for data display.