Real time video converter
AssigneeRasterOps Corporation
InventorsMichael Maietta, David M. Smith
Life of this patent
Estimating the term…
Abstract
A general purpose scan converter for converting video signals from one scan rate to another scan rate. The scan converter accepts NTSC, PAL, EGA, VGA, or other inputs in standard video formats and convert them to be displayed on a monitor. Several modes of operation including continuous frame grabbing, grab and hold image, and dynamic scaling are provided. In addition, window sizing and window location options are under user control. The input sources for video may be selected, and a robust voltage controlled oscillator is provided for timing. The converter device operates continuously in real time and provides a high resolution output signal to a monitor.
Claims23
A converter for converting a video signal from a first to a second scan rate comprising:
- a pixel buffer for storing a portion of the video signal having a first interlaced raster video scan rate;
- an address generator for determining a display location for the video signal;
- a non-interlaced raster frame buffer operatively connected to the pixel buffer for storing the video signal at a second scan rate differing from the first scan rate;
- a control sequencer operatively connected to the pixel buffer and to the address generator for providing the portion of the video signal stored in the pixel buffer and the display location to the frame buffer upon occurrence of a predetermined event;
- and
- a means for controlling in response to a user command a display size and the display location of the video signal, wherein the display is a window.
A converter for converting scan rates of video signals comprising:
- a pixel buffer for storing a portion of a video signal having a first scan rate which is that of an interlaced raster scan;
- an address generator for determining a display location for the first video signal;
- a non-interlaced raster frame buffer operatively connected to the buffer for storing video signals at a second scan rate differing from the first scan rate;
- a control sequencer operatively connected to the pixel buffer and to the address generator for providing the portion of the video signal stored in the pixel buffer and the display location to the frame buffer in real time upon receipt of a signal from the frame buffer indicating a status of the frame buffer, and upon receipt of a control signal from a host computer;
- means for providing a second video data signal under control of a host computer directly from an external source to the frame buffer;
- and
- means for determining whether the video signal or second video data signal is to be provided to the frame buffer at any particular time.
A method of converting a scan rate of a video signal comprising the steps of:
- storing a portion of the video signal which is at a first scan rate;
- providing the stored portion of the video signal to a frame buffer at a second scan rate differing from the first scan rate upon occurrence of a predetermined event;
- selectively providing, under control of a host computer, a second video data signal from an external source directly to the frame buffer;
- determining a location on a display for the video signal;
- and
- providing the portion of the video signal stored in the frame buffer to the display at the determined location.
A converter for converting from a first video signal to a second scan rate comprising:
- a buffer for storing a portion of the video signal having a first scan rate;
- an address generator for determining a display location for the video signal;
- a frame buffer operatively connected to the buffer for storing the video signal at a second scan rate differing from the first scan rate;
- means for selectively providing, under control of a host computer, a second video data signal from an external source directly to a dedicated port of the frame buffer;
- a control sequencer operatively connected to the buffer and to the address generator for providing the portion of the video signal stored in said buffer and the display location to the frame buffer upon occurrence of a predetermined event;
- and
- means for providing the portion of the video signal in the frame buffer to the display at the display location.
A device for converting a scan rate of a video signal comprising:
- means for storing a portion of the video signal which is at a first scan rate;
- a frame buffer;
- means for providing the stored portion in the frame buffer at a second scan rate differing from the first scan rate upon occurrence of a predetermined event;
- means for selectively providing, under control of a host computer, a second video data signal from an external source directly to a dedicated port of the frame buffer;
- means for determining a location on a video display for the video signal;
- and
- means for providing the stored portion of the video signal to the display at the determined location.
Dependencies are inferred from the claim text.