| 摘要 |
A data encoder is described for carrying out runlength coding. A count of zero input data values is made by a run length counter 10. The input data values are simultaneously fed to an encoded word bit length indicator 6 and encoded word generator 8 which respectively produced outputs for each input data value. An encoder state machine 12 triggers the reading into an encoder data store 16 of the current run length, encoded word bit length and encoded word at appropriate times. The encoder state machine triggers storage when a non-zero input data value is received. The encoder state machine 12 also prompts the generation and storage of continuation codes (corresponding to a predetermined maximum of zero input data values) and end of block codes (corresponding to an indication that all the subsequent input data values within a current block are zero values and can therefore be ignored) when appropriate data streams are encountered. The data encoder enables the realisation of the JPEG standards of real time. <IMAGE> |
