METHOD AND APPARATUS FOR DISPLAYING VIDEO DATA
A method of displaying consecutively first and second asynchronous video data streams on a display device, where there is a transition from the first video data stream to the second video data stream. The transition includes interrupting updating the display on the video display device during a prolonged vertical blanking interval in response to assertion of a vertical blanking pulse in the first video stream until subsequent de-assertion of a vertical blanking pulse in the second video stream, and displaying the second video data stream starting with a frame following the subsequent de-assertion of the vertical blanking pulse in the second video stream.
1 . A method of displaying video data from first and second video data streams on a video display device, said first and second video data streams comprising respectively frames separated by vertical blanking pulses, wherein said first and second video data streams are asynchronous, the method including a transition from said first video data stream to said second video data stream, said transition comprising:
displaying on said video display device video data from said first video data stream that is updated until assertion of a vertical blanking pulse terminates a frame in said first video stream;
interrupting updating said display on said video display device during a prolonged vertical blanking interval in response to assertion of said vertical blanking pulse in said first video stream until subsequent de-assertion of a vertical blanking pulse in said second video stream; and
displaying on said video display device video data from said second video data stream starting with a frame following said subsequent de-assertion of said vertical blanking pulse in said second video stream.
2 . The method of displaying video data of claim 0 , wherein said first and second video data streams are displayed consecutively
3 . The method of displaying video data of claim 0 , further comprising:
generating a switching signal for triggering said transition from said first video data stream to said second video data stream, and
updating said display on said video display device being interrupted in response to a first occurrence of assertion of said vertical blanking pulse in said first video stream following said switching signal.
4 . The method of displaying video data of claim 0 , wherein video data from said second video data stream is displayed on said video display device starting from a first occurrence of de-assertion of said vertical blanking pulse in said second video stream following said assertion of said vertical blanking pulse in said first video stream, wherein updating said display on said video display device is interrupted during said transition for a duration less than a duration of one frame of said first or second video data stream.
5 . The method of displaying video data of claim 0 , wherein said second video data stream contains live data.
6 . The method of displaying video data of claim 0 , wherein said first video data stream comprises pre-processed data stored in a memory device.
7 . A method of transitioning between displaying on a display device a first video signal to displaying a second video signal, wherein the first and second video signals comprise frames of data separated by vertical blanking pulses and wherein the first and second video signals are asynchronous, the method comprising:
receiving the first video signal and outputting the first video signal for display on the display device;
receiving a command to switch from the displaying the first video signal to the second video signal;
upon receipt of a next vertical blanking pulse of the first video signal, prolonging said next vertical blanking pulse until a new frame of the second video signal starts; and
de-asserting said next vertical blanking pulse and outputting the second video signal for display on the display device.
8 . The method of displaying video signals of claim 7 , wherein the first video signal comprises pre-processed video data stored in a memory and the second video signal comprises a real-time video stream.
9 . A video display apparatus including a video display device, and a display controller for supplying to said display device a combined video data signal comprising first and second video data streams and a transition between said first and second video data streams, said first and second video data streams comprising respectively frames separated by vertical blanking pulses, and said first and second video data streams being asynchronous, wherein said display controller is operative during said transition to include in said combined video signal:
video data from said first video data stream that is updated until assertion of a vertical blanking pulse terminates a frame in said first video stream;
a prolonged vertical blanking pulse asserted in response to assertion of said vertical blanking pulse in said first video stream, and de-asserted in response to de-assertion of a subsequent vertical blanking pulse in said second video stream; and
video data from said second video data stream starting with a frame following de-assertion of said prolonged vertical blanking pulse.
10 . The video display apparatus of claim 0 , wherein said display controller receives a switching signal that triggers said transition from said first video data stream to said second video data stream.
11 . The video display apparatus of claim 0 , wherein said display controller interrupts updating said display on said video display device in response to a first occurrence of assertion of said vertical blanking pulse in said first video stream following said switching signal.
12 . The video display apparatus of claim 0 , wherein said display controller is responsive to a first occurrence of de-assertion of said vertical blanking pulse in said second video stream following said assertion of said vertical blanking pulse in said first video stream to include in said combined video data signal video data from said second video data stream, wherein the duration of said prolonged vertical blanking interval is less than a duration of one frame of said first or second video data stream.
13 . The video display apparatus of claim 0 , wherein one of said first and second video data streams includes a live data source.
14 . The video display apparatus of claim 0 , wherein the display controller includes a pre-processor and memory data source for supplying pre-processed data stored in the memory data source for said first video data stream.
15 . A video display apparatus, comprising:
a memory for storing video data for a first video signal, the first video signal including frames of data separated by vertical blanking pulses;
a multiplexer having a first input connected to the memory for receiving the first video signal, a second input for receiving a second video signal, and a control input that receives a switch control signal for selecting between outputting the first and second video signals;
a display driver connected to the multiplexer for receiving and outputting the selected one of the first and second video signals; and
a timing generator for prolonging a vertical blanking pulse of the first video signal, wherein upon receipt of the switch control signal, the timing generator prolongs the next vertical blanking pulse of the first video signal and upon receipt of a new frame of the second video signal, de-assets the prolonged vertical blanking pulse.
16 . The video display apparatus of claim 0 , further comprising a display device connected to the display driver for receiving and displaying the selected one of the first and second video signals.
17 . The video display apparatus of claim 0 , further comprising a pixel manipulator connected between the display device and the display driver.
18 . The video display apparatus of claim 0 , a data requestor for fetching the first video signal from the memory.
19 . The video display apparatus of claim 0 , wherein the first video signal comprises pre-processed image data and the second video signal comprises a real-time video signal.