Synchronization arrangement for a compressed video signal

Claim 2

The apparatus set forth in claim 1 characterized in that said means for generating time stamps comprises: a source of clock pulses; means for counting said clock pulses modulo K, where K is an integer means for periodically capturing a count value from said means for counting.

Claim 3

The apparatus set forth in claim 1 further characterized in that; a source of further compressed signal to be time division multiplexed with said compressed video signal for transmission or storage; multiplexing means, having a plurality of input terminals, for selectively providing signal at an output terminal from one of said plurality of input terminals; a storage buffer having an input coupled to receive said compressed video signal for transmission or storage, and having an output coupled to one of said plurality of input terminals of said multiplexing means, said storage buffer arranged to store said compressed video signal for transmission or storage during intervals that said multiplexing means does not accept signal from said one of said plurality of input terminals, and includes ; a source of clock pulses; means for measuring the transit time of signal through said storage buffer in units of said clock pulses; and means for incrementing, by the measured transit time, values contained in said further data field in transport packets passed through said storage buffer.

Claim 4

The apparatus set forth in claim 1 further characterized by: a system clock for providing clock pulses; a counter for counting said clock pulses modulo K, where K is an integer ; means for periodically storing current count values provided by said counter for insertion in said ones of said transport packets; a source of precompressed video signal including time stamps for aiding system synchronization; and said transport processor circuitry includes; means for accessing said time stamps from said precompressed video signal; and means for generating said timing information related to said time stamps of precompressed video signal.

Claim 5

The apparatus set forth in claim 1 characterized in that said identifiable transport packets are auxiliary transport packets having auxiliary transport headers and payloads including said time stamps and a modifiable field for including timing information related to one of time stamps of precompressed video signal and incremental delays incurred by the auxiliary transport packet during subsequent transmission processing of said auxiliary transport packet, and wherein the header of the auxiliary transport packets includes a flag which indicates whether a field is modifiable.

Claim 6

Apparatus for providing a compressed video signal characterized by: a source of video signal; a source of precompressed video signal including count values for aiding system synchronization; compression means coupled to said source of video signal for providing compressed video signal components including descriptive headers and data representing pixel information formatted according to a predetermined protocol; a system clock for providing clock pulses; a counter for counting said clock pulses modulo K, where K is an integer ; means for periodically storing current count values provided by said counter; means including a transport processor coupled to receive formatted compressed video, and said precompressed video for providing a sequence of signal packets including said compressed video or said precompressed video, wherein ones of packets in a sequence of compressed video signal packets are identifiable as including data representing current count values and ones of packets in a sequence of precompressed video signal are identifiable as including data representing said count values and said current count values; and means for conditioning said sequence for transmission.

Claim 7

The apparatus set forth in claim 6 characterized in that said means including a transport processor includes means for dividing said compressed video signal into segments of predetermined amounts of data, and responsive to said compressed video signal headers for forming transport headers, and concatenating respective transport headers with payloads consisting of respective segments of said compressed video signal to form respective video transport packets, means for forming transport packets identifiable as including count values of information and including at least said current count values, means for forming transport packets of said precompressed video signal including packets which are identifiable as including count values and including data representing said current count values and further data representing said count values of said precompressed video signal; and means for forming a signal including a sequence of transport packets of compressed video signal and precompressed video signal.

Claim 8

The apparatus set forth in claim 6 further characterized by; a source of further signal packets; means for multiplexing said sequence of signal packets with said further signal packets; and means for modifying said count values in said sequence of signal packets as a function of incremental delays incurred by said means for multiplexing.

Claim 9

The apparatus set forth in claim 6 further characterized by; a source of further compressed signal to be time division multiplexed with said sequence of signal packets including said compressed video or said precompressed video, for transmission or storage; multiplexing means, having a plurality of input terminals, for selectively providing signal at an output terminal from one of said plurality of input terminals; a storage buffer having an input coupled to receive said sequence of signal packets including said compressed video or said precompressed video, and having an output coupled to one of said plurality of input terminals of said multiplexing means, said storage buffer arranged to store said sequence of signal packets including said compressed video or said precompressed video during intervals that said multiplexing means does not accept signal from said one of said plurality of input terminals, and includes; a source of clock pulses; means for measuring the transit time of signal through said storage buffer in units of said clock pulses; and means for incrementing the count values, in transport packets indentified as including count values which are passed through said storage buffer, by the measured transit time.

Claim 10

The apparatus set forth in claim 6 characterized in that said identifiable transport packets are auxiliary transport packets having auxiliary transport headers and payloads including said time stamps and a modifiable field for including timing information related to one of time stamps of precompressed video signal and incremental delays incurred by the auxiliary transport packet during subsequent transmission processing of said auxiliary transport packet, and wherein the header of the auxiliary transport packets includes a flag which indicates whether a field is modifiable.

Claim 11

Apparatus for synchronizing at least a portion of a compressed video signal receiving system which processes a compressed signal occurring in transport packets of compressed video signal wherein identifiable ones of said transport packets include program clock references including count values periodically obtained from a counter arranged to count modulo K, (K a positive integer) pulses of an encoding system clock, and which includes differential count values which relate to one of program clock references of data of precompressed signal multiplexed with said compressed video signal and incremental delays incurred by transport packets, said apparatus characterized by: a source of said transport packets including transport packets having said count values and differential count values; a controlled oscillator (37), responsive to a control signal E, for providing a receiver system clock; a receiver counter (36) arranged to count pulses of said receiver system clock modulo K; means (31,35), responsive to the occurrence of transport packets including said count values, for storing count values output by said receiver counter; means (32) for retrieving count values and differential count values from said transport packets and responsive to successively stored count values output by said receiver counter and corresponding said count values and differential count values from said transport packets for generating (38,39) said control signal, E, for controlling said controlled oscillator.

Claim 12

The apparatus set forth in claim 11 characterized in that said means for generating said control signal, E, includes: means for combining said count values and differential count values to form a corrected count value; means for calculating said control signal, E, proportional to: E =f(|CPCR n - CPCR n-1 | - |RCV n - RCV n-1 |) where CPCR n and CPCR n-1 are successive corrected count values and RCV n and RCV n-1 are corresponding stored count values output by said receiver clock.

Claim 13

The apparatus set forth in claim 12 characterized in that said means for combining said count values and differential count values comprises an adder.

Claim 14

The apparatus set forth in claim 11 characterized in that said identifiable transport packets include header data which identify that respective said transport packets include said count values, and said means, responsive to the occurrence of transport packets including said count values comprises a matched filter for detecting said header data.

Claim 15

The apparatus set forth in claim 11 characterized in that said means for retrieving count values and differential count values from said transport packets comprises: a controller responsive to header data in respective transport packets for generating timing signals; a demultiplexer responsive to said timing signals and said transport packets for selectively passing data in said transpackets occurring in predetermined locations; and memory means for storing data selectively passed by said demultiplexer.

Claim 16

The apparatus set forth in claim 11 further characterized by apparatus for low pass filtering said said control signal E.

Claim 17

The apparatus set forth in claim 11 characterized in that said identifiable transport packets include header data which identify that respective said transport packets include said count values, and said means, responsive to the occurrence of transport packets including said count values comprises a matched filter for detecting said header data; and wherein said means for retrieving count values and differential count values from said transport packets comprises: a controller responsive to header data in respective transport packets for generating timing signals; a demultiplexer responsive to said timing signals and said transport packets for selectively passing data in said transport packets occurring at predetermined locations in said packets; and memory means for storing data selectively passed by said demultiplexer.