Texas Instruments Corporation

Other

Karl H Renner

Weider Peter Chang

Walter Heinrich Demmer

Alec James Morton

Ramesh Chandrasekaran

Jason Meiners

Shereef Shehata

John P Shanklin

Clark R Williams

Liming Xiu

Feng Ying

Fan Zhai

Steven Derrick Clynes

Peter Chang

Apparajan Ganesan

Xiaodong Wu

Viet Dinh

Airong Amy Zhang

Darwin Renner

Synchronous circuitry for processing digital data in which the data are filtered to compensate for expected jitter in time-average frequency clock signals. Time-average frequency synthesis circuitry generates internal clock signals of a desired frequency, for example as based on a recovered clock signal from an input data stream, in a manner in which not all periods of the clock signal are of uniform duration. A jitter precorrection filter is inserted into the data path to apply a variable delay to pre-correct for distortion caused by jitter in the clock cycle. In embodiments of the invention using a flying-adder architecture to generate the clock signal, coefficients of the digital filer realizing the jitter precorrection filter are calculated according to the currently-selected oscillator phase and according to a fractional portion of a digital frequency control word.

Jitter precorrection filter in time-average-frequency clocked systems

Base band compensation for an IF stage in a television provides significant advantages over compensation applied to the composite signal. Each base band color difference signal is filtered to obtain cross-talk elements, which are then applied to the opposite channel to eliminate the cross-talk components from the color difference signal channels. The compensation technique is applicable to IF stages generally, including those based on SAW filters. High and low gain compensation of the cross-talk compensated signals may also be performed to reduce distortion in the compensated signals. The base band compensation tends to reduce or eliminate visual artifacts in a television image, especially where sharp contrast transitions occur in the image.

System and implementation for IF compensation for video decoders

A system to reduce noise includes a noise measurement device that provides a measure of noise associated with a digital input video signal. A noise reduction filter provides a noise-reduced digital output video signal corresponding to the luma and chroma of the digital input video signal. The noise reduction filter has a parameter that varies on a pixel basis for the component of the digital input video signal as a function of the measure of noise. The range and sensitivity of the noise reduction can be user programmable.

Interframe noise reduction for video

System and method for an all-digital audio receiver for a BTSC MTS audio signal or other composite signal that is FM modulated. A preferred embodiment comprises a digital FM demodulator for receiving an analog to digital quantized SIF signal and performing demodulation and outputting a composite audio signal, and a digital audio processor for decomposing the composite audio signal into at least the SAP, stereo and monaural signals for audio reproduction. In a preferred embodiment, the digital audio processor is a programmable digital signal processor. In a preferred embodiment, the digital FM demodulator and the digital audio processor are implemented as an integrated circuit. Methods for processing the audio signal using the digital processors of the invention are provided.

Method and apparatus for digital MTS receiver

Systems and methods are provided for detecting motion within a composite video signal. A first chroma difference element compares an in-phase chroma component of the composite video signal to a delayed representation of the in-phase chroma component to produce a first chroma difference value for a given pixel. A second chroma difference element compares a quadrature chroma component of the composite video signal to a delayed representation of the quadrature chroma component to produce a second chroma difference value for the pixel. A parameter mapping component maps the first and second difference values to respective first and second motion parameters that indicates the degree of change in the chroma properties of the pixel. A parameter selector determines a composite motion parameter for the pixel from the first and second motion parameters.

Motion detector for a video display system

A method for treating inter-frame motion in a series of consecutive signal frames of a composite video signal includes the steps of, for an evaluation pixel position in each frame of a test frame-set including three successive signal frames: (a) determining whether there is at least a predetermined difference in chroma component or in luma component signals at the evaluation pixel; (b) if in step (a) there is not a predetermined difference in chroma component signals or in luma component signals, determining whether a first and third frame of the test frame-set are substantially identical; (c) determining whether at least a first predetermined number of the luma or chroma component signals in the test frame-set present at least one false color; and (d) determining whether at least a second predetermined number of high frequency luma component signals exist in the test frame-set.

Method for treating inter-frame motion in a composite video signal

The present invention discloses a PLL (), which may be implemented in software, hardware, or a combination of software and hardware, which comprises a sync detector (), a loop filter (), a vertical sync discrete time oscillator (DTO) (), and an output logic () adapted to detect a vertical sync (), wherein the loop filter (), the vertical sync DTO (), and the output logic () are coupled to the sync detector ().

Equilibrium based vertical sync phase lock loop for video decoder

Systems and method are provided for luma-chroma separation. A demodulator system demodulates a composite video signal to produce at least two baseband chroma signals. A given baseband chroma signal contains chroma information for one of a plurality of video frames comprising the composite signal. A three-dimensional (3-D) comb filter removes luma information from a given baseband chroma signal by combining sets of at least two baseband chroma signals to form a 3-D filtered baseband signal.

Systems and methods for separating luma and chroma information in a composite video signal

The present invention discloses a PLL (), which may be implemented in software, hardware, or a combination of software and hardware, which comprises a sync detector () adapted to output a phase error (), a vertical sync discrete time oscillator (DTO) block () adapted to output a vertical sync DTO () based on the phase error (), and an output logic () adapted to detect a vertical sync based on the vertical sync DTO ().

The present invention discloses a horizontal sync detector circuit () comprising a filter portion (), an equilibrium accumulator portion () coupled to the filter portion (), a horizontal sync detector portion () coupled to the filter portion () and to the equilibrium accumulator portion (), and an output logic portion () coupled to the horizontal sync detector portion (), the output logic portion () adapted to produce a phase error () based on a combination of a coarse phase error () and a fine phase error ().

Equilibrium based horizontal sync detector for video decoder

In one embodiment, a method for processing a video signal includes: (1) receiving and storing luminance and chrominance information for each pixel in a first portion of the signal; (2) receiving luminance and chrominance information for each pixel in a second portion of the signal; (3) determining an estimated motion vector for each particular pixel of the second portion by comparing the luminance and chrominance information of the particular pixel to the stored luminance and chrominance information for one or more pixels in a search area of the first portion to determine a pixel in the search area that most closely matches the particular pixel and determining the estimated motion vector according to the particular pixel and the most closely matching pixel; (4) using the estimated motion vector to access the chrominance information for the most closely matching pixel; (5) using a three-dimensional comb filter to filter the chrominance information for the particular pixel and for the most closely matching pixel to determine three-dimensional filter output chrominance information for the particular pixel; (6) receiving the three-dimensional output chrominance information and if the chrominance information for the particular pixel matches the chrominance information of the most closely matching pixel within a specified tolerance, using the three-dimensional filter output chrominance information to determine output luminance information for the particular pixel; and (7) providing the three-dimensional output chrominance information and output luminance information for the particular pixel for displaying the particular pixel.

Processing a video signal using motion estimation to separate luminance information from chrominance information in the video signal

A SECAM decoder and an FM modulator therefor are disclosed, in which a demodulated color signal is provided to indicate deviations in the frequency of modulated color information from a nominal subcarrier frequency. The demodulator comprises numerator and denominator filters operating on the modulated color information, and a divider providing a ratio result by dividing the numerator filter output by the denominator filter output. The demodulator may include two sets of numerator and denominator filters offset in phase from one another, where one of the two sets is selectively employed in order to mitigate divide-by-zero problems. Also disclosed are methods for demodulating digitized FM color signals in a SECAM decoder.

FM demodulator for SECAM decoder

A phase-locked loop is provided which is operable to lock the sampling clock (pixel clock) to the incoming horizontal sync pulse contained within composite video information. Given the input signal is a VCR signal or a normal noise-free signal, there exists two modes of operation, coarse lock mode and fine lock mode, which are used in controlling the phase-locked loop. In the coarse lock mode, coarse corrections are made to a horizontal discrete time oscillator so that a fast lock may be achieve using the fine lock mode. Coarse corrections are based on a normalized sum of weighted pixels collected within a narrow gate window. Lock is achieved when the falling edge is centered within the window. Given the input signal is a television signal having noise, there exists one mode of operation where the flat window phase detector is used instead of coarse lock mode to bring the sync edge to fall within the window, where the flat window normalization constant is tuned.

Video decoder having lock algorithm that distinguishes between a noisy television signal input and a video recorder signal

In accordance with an embodiment of the present invention a microprocessor in the horizontal phased lock loop reads the horizontal timing with respect to the sync input and provides an increment incto the horizontal discrete time oscillator to make corrections in its timing to maintain lock to the sync input. The horizontal discrete time oscillator output is used to produce a pixel clock which drives the color discrete time oscillator in a color phased locked loop. A microprocessor reads a phase error between the color burst input and the color local oscillator frequency and writes an increment incto the color discrete time oscillator to maintain lock to the color burst. The horizontal phase locked loop adjusts incthat varies about nominal increment (nom_inc) by &#x394;h. The feed forward error correction for the adjustment to the color discrete time oscillator is the nomimal increment (nom_inc) and a feed forwarded scaled version of &#x394;h.

Feed forward error correction in video decoder

Caller Select allows the user to select incoming telephone numbers in the Caller ID that he wishes to receive and will ring the telephone all other numbers will be rejected and not allowed to ring the telephone Numbers may programmed either by pressing an enter switch during a review controlled by a switch or by going into the program mode by pressing a mode switch and pressing buttons on a touch tone phone The operation is controlled by software running in a low power microprocessor The Caller Select mode may be turned off by a switch which in display of the Caller ID only and ringing by all calls.

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Dallas, TX, United States of America

Karl H Renner