Patent ID: 7916994

Claim:
A signal processing apparatus for outputting an encoded stream to an external source, said signal processing apparatus comprising: storing means for storing a plurality of data; output means for outputting an encoded stream to the external source; extracting means for extracting a parameter with respect to an encoding of the encoded stream from the encoded stream supplied to the output means; determining means for determining whether or not the parameter extracted by the extracting means is an invalid parameter by comparing a value of the extracted parameter with an interdiction value or a reserved value pre-stored in the determining means and comparing the data length of the extracted parameter with a predetermined length range; and output stopping means for causing the output means to stop outputting the encoded stream when the determined result of the determining means represents that the parameter is an invalid parameter; wherein the extracting means further extracts a plurality of parameters with respect to the encoding of the encoded stream from the encoded stream and the determining means further determines whether a sequence of the plurality of parameters matches a predetermined sequence, wherein the determining means determines the extracted parameter as an invalid parameter when the data length of the extracted parameter is shorter than the predetermined length range, wherein the determining means determines a first parameter as an invalid parameter when a restriction between the first parameter and a second parameter is voilated, wherein the determining means determines the extracted parameters further based on a restrictive relationship among extracted parameters, and wherein when the encoded stream contains a syntax error or a format violation, a predetermined code is added to the stream, a portion of the encoded stream which contains the syntax error or format violation is erased, and outputting is resumed from the beginning of a portion that is immediately preceded by a next detected correct stream following the deleted portion.