| 摘要 |
PURPOSE: To automatically adjust a frequency at the time of processing video signals by a digital system by performing a modulo arithmetic operation to standard low band carrier chrominance signals in response to a calculated line jitter amount and generating frequency-corrected new low band conversion carrier chrominance signals. CONSTITUTION: A horizontal synchronization conversion part 100 initializes the horizontal synchronization error Herror1 of a line immediately before to '0', separates digital horizontal synchronizing signals by system clocks from inputted horizontal synchronizing signals and counts clocks N. A calculation part 200 calculates a present line horizontal synchronization separation error Herror2 . The actual period of the horizontal synchronizing signals of a present line is calculated and the jitter amount▵T1 of the present line is calculated. Then, a correction part 300 calculates a correction degree and then, the new low band conversion carrier chrominance signals New Fcu are generated. A counter 400 substitutes the calculated horizontal synchronization separation error Herror2 of the present line to the horizontal synchronization error Herror1 of the line immediately before and repeats the same process to the next horizontal synchronization period after delaying one horizontal synchronization period 1H.
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