Patent ID: 6310921
Filing Date: 2001-10-30
Classification: H04N

Abstract:
A media processing apparatus comprising:an input means for inputting a data stream including compressed audio data and compressed video data;a sequential processing means for performing a sequential processing which is mainly for condition judgements, the sequential processing including performing a header analysis for analyzing a header which is assigned to a predetermined unit of data (hereinafter, called a ""block"") in the data stream and performing a decoding of compressed audio data of the data stream; anda routine processing means for performing, in parallel with the sequential processing, a routine processing which is mainly for routine calculations, the routine processing including a decoding of the compressed video data of the data stream for a block using a result of the header analysis, andwherein the sequential processing means instructs the routine processing means to decode the block when the header analysis of the block is completed, and starts the header analysis of a next block when receiving notification from the routine processing means that the decoding of the block is completed,wherein the routine processing means is composed of:a data translation means for performing variable length code decoding (abbreviated as the ""VLD"" hereafter) on the compressed video data of the data stream in accordance with an instruction from the sequential processing means;a calculation means for performing inverse quantization (abbreviated as the ""IQ"" hereafter) and inverse discrete cosine transformation (abbreviated as the ""IDCT"" hereafter) by executing a predetermined calculation on a video block obtained through the VLD; anda blending means for restoring video block data by performing motion compensation processing which is achieved by blending the decoded block with the video block on which the IDCT has been performed,wherein the sequential processing means is composed of:an obtaining means for obtaining header information on which the VLD has been performed by the data translation means;an analyzing means for analyzing the obtained header information;a notifying means for reporting parameters obtained as a result of the header analysis to the routine processing means;an audio decoding means for decoding the compressed audio data of the data stream inputted by the input means; anda control means for stopping an operation of the audio decoding means and activating the obtaining means when receiving an interrupt signal from the routine processing means that indicates a decode completion of the block, and for instructing the data translation means to start the VLD on the compressed video data of the data stream when the parameters have been indicated by the notifying means,wherein the calculation means includesa first buffer having a storage area whose capacity is equivalent to one block, andwherein the data translation means includes:a VLD means for performing the VLD on the compressed video data of the data stream;a first address table means for storing a first address sequence where addresses in the first buffer are arranged in an order for a zigzag scan;a second address table means for storing a second address sequence where addresses in the first buffer are arranged in an order for an alternate scan; anda writing means for writing block data obtained through the VLD performed by the VLD means into the first buffer in accordance with one of the first address sequence and the second address sequence.