Circuitry and apparatus for converting a decoded image with a macroblock/raster scan conversion capability

摘要

Decoded image converting circuitry includes a display image compression circuit to which image data are input in the form of consecutive macroblocks. The compression circuit compresses each macroblock, a sequence of sixteen horizontal image data at a time, with a preselected compression ratio. The compressed image data representative of an I (Intra coded) picture and a P (Predictive coded) picture are written to a first memory while the compressed image data representative of a B (Bidirectionally predictive coded) picture are written to a second memory. The image data stored in the first and second memories each is read out at a preselected timing allowing raster scan data to be formed. A display image expansion circuit expands the compressed I and P pictures and B picture and thereby outputs raster scan data. An apparatus including the decoded image converting circuitry and a method practicable with the apparatus are also disclosed.