Patent ID: 6836514
Filing Date: 2004-12-28
Classification: H04L

Abstract:
A method for the detection and mitigation of one or more errors occurring within a digital bitstream having a plurality of frame information and a plurality of frame overhead information, comprising:receiving one or more blocks of frame data, said frame data comprising said frame information and said frame overhead information; applying one or more frame overhead analysis processes in order to determine whether one or more fields of the frame overhead information is in error; if the frame overhead analysis algorithm is a timestamp algorithm, further comprising: reconstructing a current absolute timestamp from one or more relative timestamps contained in the frame overhead information; determining whether the current absolute timestamp is incorrect by comparing a computed difference to a computed positive threshold value and a computed negative threshold value; and if the current absolute timestamp is incorrect, modifying the current absolute timestamp. if the frame overhead analysis algorithm is a picture start code algorithm, further comprising: if one or more addresses corresponding to one or more blocks of frame data subsequent to a first block of frame data is less than an address of the first block of frame data, calculating a number of bits received since the first block of frame data was received; if the number of bits received is less than or equal to a first computed threshold, indicating that an error occurred in the one or more addresses of the one or more subsequent blocks of data; and If the number of bits received exceeds a second computed threshold, assuming that one or more picture start codes of the one or more subsequent blocks has been incorrectly received. if the frame overhead analysis algorithm is a picture header algorithm, further comprising: receiving one or more picture headers containing one or more errant fields; and if one or more errant fields of the one or more errant picture headers are not equivalent to one or more fields of one or more correct picture headers, replacing zero, one or more fields within the one or more picture headers containing one or more errant fields.