Methods of and apparatus for digital audio signal processing

• Main Authors: CREED, DAVID MORRIS, IVE, JOHN GOODWIN SPENCER
• Format: Patent
• Language: English; French; German
• Published: 11.01.1984
• Subjects: BASIC ELECTRONIC CIRCUITRY; CODE CONVERSION IN GENERAL; CODING; DECODING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS; TRANSMISSION

@ A method of detecting and correcting errors in digital audio signals comprises assembling digital data words each of which corresponds to a digital audio signal representing an analog audio sample into units of six data words, assembling with each unit six redundant words derived by exclusive-OR operations on the data word in each row and each column of the unit, assembling the data words and redundant words into sub-blocks and adding cyclic redundancy check code words to the sub-block, recording and reproducing each sub-block, after reproduction using the code words of each sub-block to add error flags to each word in the sub-block, re-forming the units and assembling with each reproduced unit syndromes derived by exclusive-OR operations on the data words and redundant words in each row in each column of the unit, comparing the syndromes and correcting the error flags in dependence on this comparison, deriving horizontal syndromes by exclusive-OR operations on the data words and redundant words in each row of the reproduced unit and where there is only a single word in a row flagged as being in error, correcting that error word using the horizontal syndrome, and deriving vertical syndromes by exclusive-OR operations on the data words and the redundant word in each column of the reproduced unit and where there is only a single word in that column in error, correcting that error word using the vertical syndrome.