System for converting a video signal from a first format to a second format

Claim 1

An apparatus for converting a video input signal representing an image from a first format to a prescribed second format, comprising: (a) sync separator means for extracting a synchronization (sync) signal from the video input signal; (b) clock means for generating a sample clock signal on the basis of the sync signal and the said prescribed format, said clock means comprising a phase-locked loop (PLL), programmable divider means for sampling outputs of the PLL and feeding back a divided-down voltage to the PLL, counter means for totalling horizontal active and blanking intervals of the incoming video signal and generating outputs indicative of said intervals, and microprocessor means for monitoring the outputs of said counter means and setting said programmable divider means such that said PLL outputs a prescribed number of clock pulses during a horizontal active interval of the video input signal, said sampling clock signal being derived from said clock pulses; (c) sampling means for sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; and (d) combining means for combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line, whereby an array of image samples representing the image may be obtained.

Claim 2

An apparatus for converting a video input signal representing an image from a first format to a prescribed second format, comprising: (a) sync separator means for extracting a synchronization (sync) signal from the video input signal; (b) clock means for generating a sample clock signal on the basis of the sync signal and the said prescribed format, said clock means comprising a phase-locked loop (PLL), programmable divider means for sampling outputs of the PLL and feeding back a divided-down voltage to the PLL, counter means for totalling horizontal active and blanking intervals of the incoming video signal and generating outputs indicative of said intervals, and microprocessor means for monitoring the outputs of said counter means and setting said programmable divider means such that said PLL outputs a prescribed number of clock pulses during a horizontal active interval of the video input signal, said sampling clock signal being derived from said clock pulses; (c) sampling means for sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; and (d) combining means for combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line, whereby an array of image samples representing the image may be obtained.

Claim 3

An apparatus for converting a video input signal representing an image from a first format to a prescribed second format, comprising: (a) sync separator means for extracting a synchronization (sync) signal from the video input signal; (b) clock means for generating a sample clock signal on the basis of the sync signal and the said prescribed format, said clock means comprising a phase-locked loop (PLL), programmable divider means for sampling outputs of the PLL and feeding back a divided-down voltage to the PLL, counter means for totalling horizontal active and blanking intervals of the incoming video signal and generating outputs indicative of said intervals, and microprocessor means for monitoring the outputs of said counter means and setting said programmable divider means such that said PLL outputs a prescribed number of clock pulses during a horizontal active interval of the video input signal, said sampling clock signal being derived from said clock pulses; (c) sampling means for sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; (d) combining means for combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line, whereby an array of image samples representing the image may be obtained; and (e) filtering means for filtering the video input signal so as to effectively horizontally average each line of the image.

Claim 4

An apparatus for converting a video input signal representing an image from a first format to a prescribed second format, comprising: (a) sync separator means for extracting a synchronization (sync) signal from the video input signal; (b) clock means for generating a sample clock signal on the basis of the sync signal and the said prescribed format, said clock means comprising a phase-locked loop (PLL), programmable divider means for sampling outputs of the PLL and feeding back a divided-down voltage to the PLL, counter means for totalling horizontal active and blanking intervals of the incoming video signal and generating outputs indicative of said intervals, and microprocessor means for monitoring the outputs of said counter means and setting said programmable divider means such that said PLL outputs a prescribed number of clock pulses during a horizontal active interval of the video input signal, said sampling clock signal being derived from said clock pulses; (c) sampling means for sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; (d) combining means for combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line, whereby an array of image samples representing the image may be obtained; and (e) filtering means for filtering the video input signal so as to effectively horizontally average each line of the image.

Claim 10

A method for converting a video input signal representing an image from a first format to a prescribed second format, comprising the steps of: (a) extracting a synchronization (sync) signal from the video input signal; (b) generating a sample clock signal on the basis of the sync signal and the said prescribed format, said generating step comprising the following sub-steps: extracting horizontal and vertical sync and blank signals from the input video signal, generating counts of said horizontal and vertical sync and blank signals, providing a control signal on the basis of said counts, and generating said sample clock signal on the basis of said horizontal sync signal and the control signal; (c) sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; and (d) combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line.

Claim 11

A method for converting a video input signal representing an image from a first format to a prescribed second format, comprising the steps of: (a) extracting a synchronization (sync) signal from the video input signal; (b) generating a sample clock signal on the basis of the sync signal and the said prescribed format, said generating step comprising the following sub-steps: extracting horizontal and vertical sync and blank signals from the input video signal, generating counts of said horizontal and vertical sync and blank signals, providing a control signal on the basis of said counts, and generating said sample clock signal on the basis of said horizontal sync signal and the control signal; (c) sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; and (d) combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line.

Claim 12

A method for converting a video input signal representing an image from a first format to a prescribed second format, comprising the steps of: (a) extracting a synchronization (sync) signal from the video input signal; (b) generating a sample clock signal on the basis of the sync signal and the said prescribed format, said generating step comprising the following sub-steps: extracting horizontal and vertical sync and blank signals from the input video signal, generating counts of said horizontal and vertical sync and blank signals, providing a control signal on the basis of said counts, and generating said sample clock signal on the basis of said horizontal sync signal and the control signal; (c) sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; (d) combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line; and (e) filtering the video input signal so as to effectively horizontally average each line of the image, said filtering performed prior to said combining step.

Claim 13

A method for converting a video input signal representing an image from a first format to a prescribed second format, comprising the steps of: (a) extracting a synchronization (sync) signal from the video input signal; (b) generating a sample clock signal on the basis of the sync signal and the said prescribed format, said generating step comprising the following sub-steps: extracting horizontal and vertical sync and blank signals from the input video signal, generating counts of said horizontal and vertical sync and blank signals, providing a control signal on the basis of said counts, and generating said sample clock signal on the basis of said horizontal sync signal and the control signal; (c) sampling the video input signal in accordance with the sample clock signal to obtain a prescribed number of samples per line of the image; (d) combining the samples of at least two different lines to obtain a prescribed number of new lines each of which comprises the said prescribed number of samples per line; and (e) filtering the video input signal so as to effectively horizontally average each line of the image, said filtering performed prior to said combining step.