MPEG VIDEO DECODER WITH INTEGRATED SCALING AND DISPLAY FUNCTIONS

A DIGITAL VIDEO DECODER SYSTEM (40), METHOD AND ARTICLE OF MANUFACTURE ARE PROVIDED HAVING INTEGRATED SCALING CAPABILITIES FOR PRESENTATION OF VIDEO IN FULL SIZE OR A PREDETERMINED REDUCED SIZE, WHILE AT THE SAME TIME ALLOWING FOR REDUCED EXTERNAL MEMORY REQUIREMENTS FOR FRAME BUFFER STORAGE (53). THE INTEGRATED SYSTEM UTILIZES AN EXISTING DECIMATION UNIT (82) TO SCALE THE DECODED STREAM OF VIDEO DATA WHEN THE SYSTEM IS IN SCALED VIDEO MODE. DISPLAY MODE SWITCH LOGIC (96) OVERSEAS SWITCHING BETWEEN NORMAL VIDEO MODE, WHEREIN THE SWITCHING OCCURS WITHOUT PERCEPTUAL DEGRADATION OF A DISPLAY OF THE DECODED STREAM OF VIDEO DATA. SCALED DECODED VIDEO FRAMES ARE BUFFERED IN A FRAME BUFFER WHICH IS PARTITIONED DEPENDING UPON WHETHER THE DIGITAL VIDEO DECODING SYSTEM IS IN NORMAL VIDEO MODE OR SCALED VIDEO MODE. IN SCALED VIDEO MODE, THE FRAME BUFFER ACCOMMODATES BOTH FULL SIZE I AND P FRAMES, AS WELL AS SCALED I, P & B FRAMES. THE FULL SIZE I AND P FRAMES ARE USED TO SUPPORT FUTURE DECODE OPERATIONS, WHILE THE SCALED I, P & B FRAMES ARE RETRIEVED FOR DISPLAY. (FIGURE 5)