摘要 |
Authorization information, such as blackout and spotlight regions, circular blackout and spotlight regions, and tier pointers, may be transmitted from an encoder to a decoder in a plurality of sessions of data frames. By spreading the authorization information over a plurality of sessions, more space may be allocated for the provision of services. In addition, the authorization information may be framed by START and STOP fields so that the length of authorization information may be variable. Calculation of a circular blackout/spotlight region can be simplified by transmitting a distortion factor from the encoder to the decoder. Accordingly, complex calculations need not be performed at a microprocessor in the decoder. |