When a non-error-resilient application decoder receives a data stream containing syntax error due to transmission errors, such as packet losses in wireless communication, an application decoder cannot usually continue decoding the stream data anymore. According to the present invention, the data stream containing syntax error along with error correction data generated by error-detectable transmission system is inputted into an error correction part before inputted into the application decoder. The error correction part detects the error position in the data stream using the error detection data, corrects the syntax error in the stream data, and generates a stream data which is possible to be decoded by the application decoder. As a result, the data stream containing syntax error can continue decoding or be decoded in better quality by a non-error-resilient application decoder, without adding any error correcting function in the existing application decoder.