Method and apparatus for processing null packets in a digital media receiver
First Claim
1. An apparatus, comprising:
- a Null-Packet Detector for processing a stream of fixed-length packets received by said apparatus as digitally encoded signals and having multiple packet types, each packet including a header portion and a data portion, the header portion including a sync byte,wherein said Null-Packet Detector processes the stream by detecting whether a received packet is a null-packet and for identifying the location of the sync-byte of a detected null-packet, andwherein the Null-Packet Detector further generates a first signal to indicate whether a received packet is a null-packet and generates a second signal to indicate the location of the sync-byte of a detected null-packet.
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Accused Products
Abstract
A method and apparatus for reliably detecting MPEG-2 packet sync-byte positions received via a digital transmission system in the event of a packet stream containing a plurality of null packets of a plurality of packets containing a fixed repeating bit pattern and for reliably synchronizing and delivering the MPEG-2 stream broadcast to the receiver transport layer. A Null-Packet Detector compares the content of the current packet with a fixed (or predetermined) bit pattern to detect a null packet to reliably identify the location of the sync-byte of the null packet. a sync-byte position is identified based upon the position of the predetermined fixed bit pattern in the header portion of a plurality of null-packets in the stream.
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Citations
36 Claims
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1. An apparatus, comprising:
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a Null-Packet Detector for processing a stream of fixed-length packets received by said apparatus as digitally encoded signals and having multiple packet types, each packet including a header portion and a data portion, the header portion including a sync byte, wherein said Null-Packet Detector processes the stream by detecting whether a received packet is a null-packet and for identifying the location of the sync-byte of a detected null-packet, and wherein the Null-Packet Detector further generates a first signal to indicate whether a received packet is a null-packet and generates a second signal to indicate the location of the sync-byte of a detected null-packet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An apparatus comprising:
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a Syndrome Detector for processing a stream of fixed-length packets received by said apparatus as digitally encoded signals and having multiple packet types, each packet including a header portion and a data portion, the header portion including a checksum-encoded sync byte, the stream processed by detecting the checksum-encoded sync-byte and generating a Sync_flag signal to indicate the location of the checksum-encoded sync-byte; a Null-Packet Detector adapted to detect whether a received packet is a null-packet, and adapted to identify the location of the sync-byte of a detected null-packet; and an MPEG Sync-Byte Re-insertion circuit for inserting a predetermined value into the sync-byte location indicated by an MPEG synchronization signal. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A method comprising:
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processing a stream of fixed length packets received by said method as digitally encoded signals, each packet including a checksum-encoded sync-byte, the stream including a plurality of packets that each contain a first fixed bit pattern in the header portion of each packet, wherein said processing step comprises; performing a first detection step of decoding the checksum in the stream to detect a checksum-encoded sync byte position candidate in the current one of the fixed length packets; performing a second detection step to detect the first fixed bit pattern in the header portion of the current one of the fixed length packets; if the first fixed bit pattern is detected in the stream of fixed length packets, then identifying the sync-byte position of the sync-byte of each of the fixed length packets based upon the detection of the first fixed bit pattern; and inserting a predetermined sync-byte value into the identified sync-byte position. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 35, 36)
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33. A method comprising:
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processing a stream of fixed length packets received by said method as digitally encoded signals, each packet including a checksum-encoded sync-byte, the stream including a plurality of packets that each contain a first data pattern in a PID portion, wherein said processing step comprises; decoding the checksum in a preceding one of the fixed length packets to detect a checksum-encoded sync byte candidate in a current one of the fixed length packets; and if a checksum-encoded sync byte candidate is detected in the decoding step, then searching for the first data pattern in the PID portion of the current one of the fixed length packets.
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34. An apparatus comprising:
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means for processing a stream of fixed length packets received by said apparatus as digitally encoded signals, each packet including a checksum-encoded sync-byte, the stream including a plurality of packets that each contain a first data pattern in a PID portion, wherein said means for processing comprises; means for decoding the checksum in a preceding one of the fixed length packets to detect a checksum-encoded sync byte candidate in a current one of the fixed length packets; and means for searching for the first data pattern in the PID portion of the current one of the fixed length packets when a checksum-encoded sync byte candidate is detected in the decoding step.
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Specification