PURPOSE: To attain picture signal processing for various broadcasting media by a simple constitution by converting the data rate of a bit stream of digitally transmitted picture data into data having fixed data volume in a fixed period.

CONSTITUTION: A digital picture component in digital picture data is converted and decoded by a variable length code decoding circuit 25 so that the data rate of a bit stream has fixed data volume in a fixed period. The decoded data are supplied to an image decoding digital signal processor(DSP) 23 and decoded. On the other hand, an analog sound signal in an analog base band signal is converted into digital sound data by an A/D converter 19 and an image signal is inputted to the DSP 23. Since the DSP 23 can be shared to the decoding processing of the digitally transmitted image data and the decoding processing of analog transmitted picture data, the picture signal processing of various broadcasting media can be attained by the simple constitution.