DECODING OF DIGITAL DATA INCLUDING PROGRAM SPECIFIC INFORMATION

摘要

PURPOSE: A decoding method minimizes the use of incorrect program specific information (PSI) parameters across program boundaries and provides default video and audio outputs for reproduction during error conditions. CONSTITUTION: Program representative packetized data streams incorporating PSI suitable for use in recovering data content of the program are decoded (25). PSI packets in the data stream are identified (33) and a parameter within the identified PSI data is used to determine whether the identified PSI data is to be used for decoding the program content, irrespective of previous PSI content. Current PSI is updated (115) with the identified PSI data in response to the parameter. Program content packets are identified (33) using the current PSI. The program content packets are assembled (55, 60, 65, 70) into a decoded data stream using the current PSI. The current PSI may also be updated with the identified PSI data irrespective of the content of the identified PSI data, provided that there is an absence of a PSI content error indication. Also packets representing default program content are assembled into the output data stream, in response to a PSI validity indication provided by a control parameter in the packetized data stream.