When a stream encoded with a variable length code is output, a stream containing a syntax error and a format violation is prevented from being output.A checker checks encoding parameter for a stream that is reproduced from a magnetic tape and a stream that is output through an EE path and determines an occurrence of a syntax error or a format violation. When the output stream contains it, a switch circuit stops outputting the stream in the unit of a GOP or a picture and adds a code representing the end to the immediately preceding stream. The checker continuously checks the stream. When the output stream does not contain an error, etc, the output of the stream is resumed from the beginning of a GOP. At that point, flag representing that there is a picture that has not been used due to the stop of the stream is added.