| 摘要 |
A digital television system in which siganls are sampled at 13.5 MHz and produce an integer number of samples during each horizontal line interval whether the signals are based upon PAL/S.E.C.A.M. or NTSC standards. In order to make the digital system hierarchical and to adapt it for simple transcoding from an NTSC signal sampled at 4 times color subcarrier, the number of samples occurring during the active portion of each horizontal line in the digital system is made equal to 704. Transcoding by interpolation from 4XCS-sampled NTSC video to the digital system is accomplished by selecting a particular number of samples per active line namely 748 such that small blocks of samples can be transcoded independently, which allows interpolation to be achieved simply. A similar transcoding scheme is also described for PAL signals. <IMAGE> |
