Apparatus for formatting a packetized digital datastream suitable for conveying television information
First Claim
1. A system (FIG. 12) for processing a packetized digital datastream (MPEG Byte Data In) to produce an output datastream (Symbol Data Out) representing sequential datafield structures each containing data and overhead information, said system comprising:
- input means (14, 24,
30) for providing a datastream of data packets separated by inter-packet data gaps;
means (48) for providing a field overhead information segment (Field Sync) having a duration different than the duration of inter-packet gaps within a data field; and
processing means (16,
50) responsive to said datastream from said input means and to said field overhead segment for producing an output datastream (Symbol Data Out) representing a sequence of datafield structures (FIG.
1) each comprising a field overhead segment and a data field containing a group of data segments (X);
whereinsaid input means provides said datastream with predetermined constant uniform inter-packet gaps over a plurality of said datafield structures, said uniform inter-packet gaps being dimensioned to facilitate the insertion of overhead information.
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Accused Products
Abstract
A transmission processor (16) receives an input packetized datastream (FIGS. 6-9; FIGS. 15-18 signal A) containing packets of data bytes including MPEG coded video information. The transmission processor outputs a symbol datastream (FIGS. 15-18 signal F) representing a sequence of data fields (FIG. 1) comprising groups of data segments (X) with an associated field sync segment. The transmission processor inserts overhead information. e.g., FEC error coding information, into each data segment, and inserts the longer duration field sync overhead segment between groups of data field segments. The frequency of the transmission processor input byte clock (SC/2, FIG. 6; FIG. 15) an integer sub-multiple of an output symbol clock (SC) frequency. The input datastream exhibits constant uniform inter-packet data gaps and a constant uniform data rate, thereby facilitating the seamless insertion of the field sync overhead segment into the datastream without interrupting the datastream. Similar but inverse processing occurs at a receiver.
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Citations
33 Claims
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1. A system (FIG. 12) for processing a packetized digital datastream (MPEG Byte Data In) to produce an output datastream (Symbol Data Out) representing sequential datafield structures each containing data and overhead information, said system comprising:
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input means (14, 24,
30) for providing a datastream of data packets separated by inter-packet data gaps;means (48) for providing a field overhead information segment (Field Sync) having a duration different than the duration of inter-packet gaps within a data field; and processing means (16,
50) responsive to said datastream from said input means and to said field overhead segment for producing an output datastream (Symbol Data Out) representing a sequence of datafield structures (FIG.
1) each comprising a field overhead segment and a data field containing a group of data segments (X);
whereinsaid input means provides said datastream with predetermined constant uniform inter-packet gaps over a plurality of said datafield structures, said uniform inter-packet gaps being dimensioned to facilitate the insertion of overhead information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In a system (FIG. 14) for receiving a digital datastream (Symbol Data In) representing a sequence of datafield structures (FIG. 1) each including a group of field data segments (X) and a field overhead segment (Field Sync) containing data different from data contained in said data segments, apparatus comprising
input means (114, FIG. 13A) for providing said datastream (Symbol Data In); -
processing means (116 in FIG. 13A;
68-80 in FIG.
14), including means (48) for removing said overhead information from said datastream, responsive to said datastream for producing a processed packetized datastream (MPEG Byte Data Out) devoid of said overhead information and comprising data packets with constant uniform inter-packet gaps and a constant uniform data rate; anddecoder means (85) responsive to said processed uniform data rate datastream for decoding said processed datastream into constituent signal components. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. In a system (FIG. 14) for receiving a continuous digital datastream (Symbol Data In) of contiguous data segments representing a sequence of datafield structures (FIG. 1), each datafield structure including a group of field data segments (X) with associated segment overhead information (FEC) and a field overhead segment (Field Sync), wherein (a) said data segments and said field overhead segment are of equal duration (188 Bytes), (b) said field overhead segment contains data different from data contained in said data segments, and (c) field overhead segment exhibits a duration different than the duration of said segment overhead information;
- apparatus comprising
input means (114, FIG. 13A) for providing said datastream (Symbol Data In); processing means (116 in FIG. 13A;
60-80 in FIG.
14) responsive to said datastream for producing a processed packetized datastream (MPEG Byte Data Out) devoid of said overhead information and comprising data packets with constant uniform inter-packet gaps and a constant uniform data rate, without interrupting said datastream;decoder means (85) responsive to said processed uniform data rate datastream for decoding said processed datastream into constituent signal components; and video processor means (122) responsive to output signals from said decoder means. - View Dependent Claims (29, 30, 32, 33)
- apparatus comprising
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31. A system according to claim , wherein
said received datastream is a symbol datastream; - and
said processed packetized datastream is a byte datastream.
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Specification