Block-based negative filtering of MPEG-2 compliant table sections
First Claim
1. A method of filtering a datastream containing transport table sections, said method comprising steps ofdetermining presence of transport table sections in a payload portion of a packet of said datastream from a table identification (TID) field in a header of said packet,filtering a portion of said transport table sections in accordance with a mask which defines a filter function and a logic state of a not match bit to provide a compare result,selecting a next mask and a portion of said transport table sections in accordance with a filter ID, andcombining compare result values in accordance with a logic values of not match bits in a not match indication register,whereby an arbitrary length of said transport table sections are filtered by an arbitrary number of filters having arbitrary filter functions.
1 Assignment
0 Petitions
Accused Products
Abstract
Positive negative and mixed digital filtering over an arbitrary variable length bit string of a datastream by evaluating bits, bytes or any other desired granularity in accordance with a mask, a filter and a not match byte. Results are accumulated over a plurality of data blocks by ANDing of compare result values similarly representing match and not match results identically depending on the not match bit except where negayive logic has been applied over an entire data block. The preferred form of the digital filter is particularly adapted to be MPEG-2 compliant.
-
Citations
14 Claims
-
1. A method of filtering a datastream containing transport table sections, said method comprising steps of
determining presence of transport table sections in a payload portion of a packet of said datastream from a table identification (TID) field in a header of said packet, filtering a portion of said transport table sections in accordance with a mask which defines a filter function and a logic state of a not match bit to provide a compare result, selecting a next mask and a portion of said transport table sections in accordance with a filter ID, and combining compare result values in accordance with a logic values of not match bits in a not match indication register, whereby an arbitrary length of said transport table sections are filtered by an arbitrary number of filters having arbitrary filter functions.
-
8. A method of filtering a datastream, said method comprising steps of
filtering a portion of said datastream in accordance with a logic state of a not match bit and a Filter ID to provide a compare result, and combining compare result values in accordance with a logic values of not match bits in a not match indication register corresponding to said portion, whereby an arbitrary length of said datastream is filtered by an arbitrary filter function.
Specification