Treating play back bit stream

The equipment is used to reproduce bit stream signal from CD and the bit stream is so controlled that only the required bit stream data are coupled for MPEG decoding. The converter is re-located to obtain required bit stream data before completing MPEG image decoding. The bit stream data are read out before buffer storing, so that required data are selected and stored while refusing unwanted data. The buffer memory is re-allocated for trick playing operation and randomly accessed for image selection in trick playing. The MPEG image decoding and storing is controlled, so as to complete frame decoding in one field period and store and read out decoded image simultaneously within a field period.