Abstract: A device and method for utilizing a single clock signal to generate a digital data stream signal for transmission in a compressed domain transmission system. The device includes a plurality of packetized elementary stream encoders electronically coupled to a transport stream encoder electronically coupled to an output interface adapted to generate the digital data stream signal.

Abstract: In a compressed domain digital communications system, a method for reducing a variable latency associated with a buffer and at least partially resulting from at least one splice between a FROM bitstream and a TO bitstream each including data corresponding to a plurality of frames, the method including: selectively deleting data corresponding to a select at least one of the frames from the buffer based upon the variable latency so as to reduce the variable latency when an amount of data corresponding to a number of frames present in the buffer is greater than a given number of frames; and, regulating a flow of data in the system to prevent an underflow condition in the system by effecting a repeat last frame command and prevent an overflow condition in the system by slowing a rate of transmission for the data associated with at least one of the frames in the TO bitstream.

Abstract: A method and apparatus for preserving audio and video presentation synchronization during the splicing operation by selectively deleting, if necessary, an audio/video access unit to avoid overlapping of audio/video frames in the spliced output stream.

Abstract: A method and apparatus for splicing a first compressed digital information stream into a second compressed digital information stream. The first information stream includes at least one entrance indicium identifying an appropriate stream entrance point, the second information stream includes at least one exit indicium identifying an appropriate stream exit point. A controller monitors the two streams until the appropriate points are found and, in response to a control signal, splices the first stream into the second stream.

Abstract: An apparatus and method for receiving an information stream comprising a plurality of timing portions and associated payload portions, decoding each timing portion, determining a duration parameter of a payload portion associated with the decoded timing portion, and recoding the timing portion using the duration parameter and a local reference time parameter.

Abstract: A transmitted high definition television signal is represented by a packetized datastream configured as a sequence of data fields (FIG. 1) with a non-uniform data rate due to unequal inter-data overhead information intervals. Each data field is prefaced by a Field Sync overhead segment followed by 312 packetized data segments each with associated overhead information (FEC). At a transmitter (FIG. 33), a transport processor (14) forms data packets with associated headers and exhibits uninterrupted operation at a constant uniform data rate, while supplying a packetized datastream to a network (17) which constructs sequential data fields by inserting the non-data overhead information into the datastream. The transport processor is advantageously operated at a constant uniform data rate without having to modify the original data field structure to accommodate the needs of the data field construction network.

Abstract: A system and method for distribution of a clock signal of a new timing reference which may employ an existing NTSC distribution network present in a conventional NTSC studio. NTSC-compliant horizontal, vertical, or other composite synchronization signals are generated from an HDTV primary reference clock, and are synchronized and locked to the HDTV primary reference, for distribution over the existing NTSC distribution network. HDTV studio components receive the horizontal, vertical, or other composite synchronization signals and generate a local HDTV clock signal using a phase-locked loop frequency synthesizer. The signal generated by the phase-locked loop frequency synthesizer is synchronized and locked to the HDTV primary reference.

Abstract: A timing synchronization method and apparatus for processing a compressed information stream comprising a plurality of information segments representative of a sequence of information frames. Information segments representative of information frames are deleted in response to an indicium of buffer overutilization.

Abstract: A studio to transmitter link (STL) that comprises a relatively low error rate communication channel implements error correction techniques at the studio side which are designed to reduce errors in the combined low error rate STL channel and a relatively high error rate communication channel used by the transmitter.

Abstract: A transmitted high definition television signal is represented by a packetized datastream configured as a sequence of data fields with a non-uniform data rate due to different types of different duration non-data overhead information. Each data field is prefaced by a Field Sync overhead segment followed by 312 packetized data segments each with associated overhead information. At a transmitter, a transport processor forms data packets with associated headers and exhibits uninterrupted operation at a constant uniform data rate, while supplying a packetized datastream to a network which constructs sequential data fields by inserting the non-data overhead information into the datastream. The transport processor is advantageously operated at a constant uniform data rate without having to modify the original data field structure to accommodate the needs of the data field construction network.

Abstract: A transport stream encoder comprises a plurality of component signal sources. One of the component signals sources is a source of an opportunistic data component signal carrying a block of data having a predetermined size to be transferred within a predetermined period of time. A packet generator is coupled to the plurality of component signal sources, and produces a composite packet stream, partitioned into successive groups containing a plurality of packet slots. A memory stores a plurality of priority lists respectively associated with the plurality of packet slots. Each priority list contains a plurality of entries, and each entry contains data representing a respective one of the plurality of component signal sources. A scheduler is responsive to the entries in the plurality of priority lists and conditions the packet generator to generate a packet for each one of the packet slots.

Abstract: A system of the present invention addresses the difficulty of aligning a reference sync byte at the beginning of a data packet during situations where the system experiences severe problems such as arbitrary resets/restarts or transmission disturbances. Specifically, the sync byte at the beginning of the data packet is automatically aligned with the beginning of a data acquisition interval when data is requested, even when there are arbitrary system resets/restarts. The alignment of the first data packet following a system reset is facilitated by the use of a Start Of Packet flag concurrent with the reference byte, together with a controlled logic network.

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.

Abstract: A method is disclosed for optimizing the operation of a packet transport system generating a packet stream carrying a plurality of component signals, and includes the following steps. First the packet stream is partitioned into successive groups, each group containing a predetermined number of packet slots. A plurality of lists are maintained, one associated with each packet slot in a group. A packet stream is generated by placing data representing a component signal selected in response to entries in the list associated with that packet slot into the packet slot. The contents of the plurality of lists are updated based on a predetermined parameter.