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US 2002/0118045 A1Published application
Method and apparatus for detecting change in video source material
AssigneeThomson Licensing
InventorKarl Francis Horlander
Life of this patent
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Abstract
A signal processing method and apparatus in which a horizontal and/or vertical synchronizing signal related to a received video signal is monitored to determine if a relatively large change has occurred in the respective vertical and/or horizontal time period such that a change in video signal source may have occurred. Upon the detection of such a change, the operation of a phase lock loop (PLL) such as horizontal phase lock loop (HPLL) and/or vertical phase lock loop (VPLL) circuit is adapted as appropriate.
Claims12
Apparatus, comprising:
- a timer, for associating temporal information with each of a sequence of received synchronization pulses;
- a first differencer, for measuring temporal differences between successive synchronization pulses to determine respective synchronization pulse timing intervals;
- a second differencer, for measuring temporal differences between successive synchronization pulse timing intervals;
- and
- a comparator, for producing a control signal indicative of whether differences between successive synchronization pulse timing intervals exceed a threshold level.
2 more elements
A method, comprising:
- associating temporal information with each of a sequence of received synchronization pulses;
- measuring temporal differences between successive synchronization pulses to determine respective synchronization pulse timing intervals;
- measuring temporal differences between successive synchronization pulse timing intervals;
- and
- providing indicia of whether differences between successive synchronization pulse timing intervals exceed a threshold level.
2 more elements
Dependencies are inferred from the claim text.