| 摘要 |
A video signal is converted to a bit stream by coding and quantising and storing in a buffer store and transmitted on a transmission line at a constant bit rate. A certain number k of frames of the video signal are skipped between each coded frame, whereby the number k is based on the transmission rate R, the frame rate fo of the video signal and minimum value (bR/fo) set for the content of the buffer store. The number of skipped frames is selected so that the buffer store is not emptied below the set lower limit before the next frame is coded. The buffer store content is also regulated by skipping or setting to zero certain components eg DCT frequency coefficients, in the bit stream from the coder. The actual and ideal buffer store contents are determined and selected components of the bit stream are set to zero in dependence on the difference between the actual and the ideal content values. <IMAGE> |
