| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an audio synchronizer for a digital television broadcast without using a VCXO (Voltage Controlled Crystal Oscillator) and a high frequency clock. <P>SOLUTION: The audio synchronizer for the digital television broadcast includes: a clock generation section that generates a fundamental clock pulse by demultiplying a clock pulse of a given frequency, which is generated by multiplying an input clock pulse, by a predetermined demultiplication ratio; a comparison section that compares reference time information included in a broadcast wave with time information counted by means of the fundamental clock pulse generated by the clock generation section; a control section that commands the clock generation section to adjust a frequency of the fundamental clock pulse in accordance with information about a time difference acquired from the comparison section; a sampling clock generation section that generates a sampling clock pulse on the basis of the fundamental clock pulse; and a sampling rate conversion section that performs sampling conversion so as to synchronize the audio sampling clock pulse and audio data included in the broadcast wave with a sampling clock of an audio DAC (Digital Analog Converter). The clock generation section inserts a clock pulse having a different demultiplication ratio at intervals equivalent of a predetermined number of clock pulses in accordance with a command from the control section. <P>COPYRIGHT: (C)2009,JPO&INPIT |
