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Moving Picture Expert Group 1 audio parser

The success encountered by the International Standards Organization Moving Picture Expert Group 1 (ISO MPEG 1) Audio standard has permitted the marketing of many coding boards and software. Faced with the difficulties that the developers had for decoding some binary flows, a parser has been developed which detects any nonconformity of a compressed file regarding the standard. The ISO MPEG1 Audio standard does not call for a special coding algorithm, on the contrary it defines precisely the syntax of the binary flow coming out of the coder, and, therefore, calls for several constraint types:
it forbids some values for the coded samples, or for the lateral information;
it keeps the information within a strictly limited space;
it appeals for a special management of the stuffing bits;
it authorizes an error detecting code for the most sensitive information. Depending on any of these syntax errors and where they are placed, the functioning of the decoder may become erratic. The parser is coded in C-ANSI language that may be compiled on any of the following machines: PC, MAC, indigo station, SUN, and even a processor with fixed-point arithmetic. It gives an especially quick executable program. Whenever a noncompatibility has been detected, an error file is created, beginning with a recall for the correspondences between the error messages and the parts of the ISO standard that are concerned, and after that a precise localization of each noncompatibility. The analyser layout is in conformance with the 11172-4 ISO standard which defines the compatibility with MPEG1 Audio standard. Main applications of this technology are in compatible coders for use in broadcasting or for multimedia applications with broadcasting of binary flows.

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