| 摘要 |
APPARATUS FOR DEVELOPING SYNCHRONIZATION OF AN INTERMEDIATE LAYER OF SIGNAL SUCH AS THE TRANSPORT OR MULTIPLEX LAYER OF A MULTI-LAYERED COMPRESSED VIDEO SIGNAL, INCLUDES AT THE ENCODING END OF THE SYSTEM APPARATUS (13, 23, 25) FOR INCLUDING A TIME STAMP REFERENCE, SUCH AS A COUNT VALUE FROM A MODULO K COUNTER (23), AND PROVISION FOR A DIFFERENTIAL TIME STAMP RELATED TO TIME STAMPS OF A FURTHER COMPRESSED SIGNAL OR DIFFERENTIAL TRANSIT TIMES OF RESPECTIVE TRANSPORT PACKETS. FLAGS ARE INCLUDED IN TRANSPORT PACKETS OF SIGNAL TO INDICATE THE PRESENCE OR ABSENCE OF THE TIME STAMPS OR DIFFERENTIAL TIME STAMPS. AT THE RECEIVING END OF THE SYSTEM, CIRCUITRY EXAMINES RESPECTIVE PACKETS FOR THE CONDITION OF THE FLAGS TO LOCATE SPECIFIC INFORMATION SUCH AS THE TIME STAMPS AND DIFFERENTIAL TIME STAMPS. A COUNTER (27) IS RESPONSIVE TO A CONTROLLED RECEIVER CLOCK SIGNAL AND THE COUNT VALUE OF THIS COUNTER IS SAMPLED AT THE ARRIVAL OF TRANSPORT PACKETS INCLUDING A FLAG INDICATING THE PRESENCE OF A TIME STAMP. CIRCUITRY IS DESCRIBED FOR USING THE TIME STAMPS AND THE SAMPLED COUNT VALUES OF THE RECEIVER COUNTER (36) TO PROVIDE A SIGNAL FOR CONTROLLING THE FREQUENCY OF THE RECEIVER CLOCK SIGNAL.(FIG 3) |
