摘要:
In a digital television signal processing system, a special codeword, a Packet Alignment Flag (PAF (14), is inserted into an MPEG codeword bitstream to signify the presence of a Group of Pictures (GOP). The PAF immediately precedes a Picture Start codeword for an "I" frame, which initiates a GOP. A data packet (12) under construction when a PAF (14) appears is terminated since a GOP is intended to begin at a packet boundary. Such termination may result in an abbreviated packet of less than a prescribed number of codewords needed to complete a data packet. The last word of each packet is designated as such to facilitate the subsequent combining of data packets (12) with respective headers (18). An incomplete data packet is filled with null (zeroed bits) words to make up a complete data packet with a prescribed number of words.
摘要:
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.
摘要:
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.
摘要:
In a digital television signal processing system, a special codeword, a Packet Alignment Flag (PAF), is inserted into an MPEG codeword bitstream to signify the presence of a Group of Pictures (GOP). The PAF immediately precedes a Picture Start codeword for an "I" frame, which initiates a GOP. A data packet under construction when a PAF appears is terminated since a GOP is intended to begin at a packet boundary. Such termination may result in an abbreviated packet of less than a prescribed number of codewords needed to complete a data packet. The last word of each packet is designated as such to facilitate the subsequent combining of data packets with respective headers. An incomplete data packet is filled with null (zeroed bits) words to make up a complete data packet with a prescribed number of words.
摘要:
In a digital television signal processing system, a special codeword, a Packet Alignment Flag (PAF), is inserted into an MPEG codeword bitstream to signify the presence of a Group of Pictures (GOP). The PAF immediately precedes a Picture Start codeword for an "I" frame, which initiates a GOP. A data packet under construction when a PAF appears is terminated since a GOP is intended to begin at a packet boundary. Such termination may result in an abbreviated packet of MPEG codewords less than a prescribed number of bits needed to complete a data packet. The last word of each packet is designated as such to facilitate the subsequent combining of data packets with respective headers. An incomplete data packet is filled with null (zeroed bits) words to make up a complete data packet with a prescribed number of bits.
摘要:
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. This result is facilitated by transferring data from the transport processor to an associated interface/buffer network in response to a 3/8 symbol clock, in combination with a predetermined buffer fullness level. A counterpart transport processor/decoder at a receiver coacts with a data field processor and similarly exhibits uninterrupted operation at a constant uniform data rate.
摘要:
An apparatus and method for receiving a bitstream containing timing information and respective program information, the program information is processed and associated with locally generated timing information to form an output bitstream, the locally generated timing information is synchronized to the received timing information so that the timing relationships of the received program information are preserved even after the program information is processed.
摘要:
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.
摘要:
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.
摘要:
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. The method includes: operating each of the packetized elementary stream encoders responsively to the single clock sequence to generate a plurality of packetized elementary stream signals; operating the transport stream encoder responsively to the single clock signal to form a transport stream signal from the plurality of packetized elementary stream signals, wherein the transport stream signal includes a plurality of data packets each formed using the transport stream encoder and select ones of the plurality of data packets formed by the transport stream encoder include synchronization data; and, operating the output interface responsively to the single clock reference to output the digital data stream signal in compliance with an predefined manner.