Abstract: The invention provides for an optical disc encoding and decoding system in which in an encode mode the system is arranged to encode Long Distance Code (LDC) clusters from user data and including error correction means for applying error correction to LDC blocks, and interleaving means arranged to form the LDC clusters by interleaving the LDC blocks, wherein the error correction means comprises a plurality of buffers at least one of which is arranged to retrieve data from a SDRAM of the system and to calculate syndromes and at least another of which is arranged to insert parity bytes in the data prior to return to the SDRAM and wherein while the said another of which buffers stores data and calculates syndromes, the said one of which buffers is arranged to insert parity bytes into the data it previously stored, the interleaving means comprising a plurality of buffers arranged for burst access for retrieving data from the SDRAM of the system.

Abstract: A multi-beam optical disc system is disclosed for recording on DVD or CD optical discs. Recorded data includes inner and outer error protection codes applied to data blocks having a predetermined size. Each block comprises several sectors. Multi-channel read-out provides in parallel a set of N sub-sequences, without restriction to the block or sub-block boundaries. Sector ID codes are detected within each channel to identify a series of sub-blocks forming a part of a data block and, even in the absence of data from the start of the block, outer error protection circuitry processes the sub-blocks to accumulate a partial error protection syndrome for the block. Upon reaching the end of the block, a syndrome for a next block within the subsequence is accumulated.

Abstract: A range of architectures are disclosed for a practical multi-beam DVD system (or a CD system) recorded in a linear sequence on an optical disc. The data incorporates inner and outer error protection codes (PI, PO), the outer code being applied on the basis of a predetermined size of data block (ECC frame). Each block comprises a series of several sectors. Multi-channel read-out provides in parallel a set of N sub-sequences, starting without restriction to said block or sub-block boundaries. Sector ID codes are detected within each channel (a, b, c, d) to identify a series of sub-blocks forming a part of a data block and, even in the absence of data from the start of the block (blocks marked *), outer error protection circuitry 216 processes the sub-blocks to accumulate a partial error protection syndrome relating to said block. Upon reaching the end of said block, a syndrome for a next block within the subsequence is accumulated.