| 摘要 |
On encoding a cluster and run sequence comprising clusters of non-zero signal elements and runs of zero signal elements into a code sequence with application of a compression encoding scheme selectively to the clusters and without application of the encoding scheme to the runs, a mode code is used to indicate application of the encoding scheme to each selected cluster and to represent a zero signal element next preceding the selected cluster in a next preceding run. In the code sequence, the mode code next precedes a succession of amplitude codes representative of the selected cluster and next succeeds a run length code preferably representative of that run length of the next preceding run from which the next preceding zero signal element is reduced. Alternatively, the mode code may indicate switching between application and non-application of the encoding scheme to partial sequences each of which starts with a cluster next succeeded by a run. In either event, a particular code is preferably used to indicate an end of each run. On decoding, the mode code is detected preferably with reference to the particular code to decide whether or not each amplitude code succession should be decoded according to an expansion decoding scheme which corresponds to the encoding scheme. |
