The Grass Valley Group, Inc.

Tektronix, Inc.

Other

John Abt

Richard A Jackson

Ronnie D Barnett

James A Delwiche

Richard S Bannister

James E Blecksmith

Kevin D Windrem

Neil R Olmstead

Richard A Frasier

Peter D Symes

Thomas A Grancey

Raymond C Blackham

David E Lake, Jr

Brion L Dunbar

James V Squier, Deceased

Nathan Osborn

To provide an improved non-additive mixer, a first mixer mixes first and second video signals according to a mixer control signal derived in a new way. The first and second video signals are applied, respectively, to first and second chrominance (blocking) filters. The resulting first and second luminance signals are applied, respectively, to first and second summing circuits, where offsets may be applied to either or both of them. The difference is then taken between the first offset luminance signal and the second offset luminance signal to produce a difference luminance signal. The difference luminance signal is then multiplied by a gain control signal to produce the mixer control signal. The mixer control signal can also be used to control a second mixer, thereby providing a channel for keying information that is non-additively mixed according to the luminance content of the video signal that the key information is associated with.

Non-additive video mixer

A video effect is created with a video processing machine having a plurality of functions, each of which has a state that is selectively variable in response to change in an associated function parameter. The method comprises selecting a set of functions, specifying a starting keyframe containing a starting value for each of the parameters, specifying an ending keyframe containing ending values for the parameters associated with the functions of the selected set and vacancies for the other parameters associated with other functions, and specifying a number of video frames. The starting keyframe is used to place the machine in a starting state, in which each function has the status defined by the value of its associated parameter in the starting keyframe, and a first video frame is processed with the processing machine in the starting state. The starting keyframe, the ending keyframe and the number of video frames are used to calculate a next frame value for each of the parameters associated with a function in the selected set. The next frame values are used to place the machine in a next frame state, in which each function of the set has the status defined by the next frame value of its associated parameter, while maintaining unaltered the values of the parameters associated with the other functions, and the next video frame is processed with the machine in the next frame state.

Method of creating video effects by use of keyframes

A pseudo-random pattern generator has modifiable feedback so that a variety of pseudo-random video patterns can be generated and used either directly, or after further manipulation, to control the mixing of two video sources. Control of a multiplexer allows a variety of pattern lengths to be selected by altering which stages of a shift register are supplied to a feedback exclusive-OR gate. Patterns with controllable granularity can be achieved by stretching each part of the noise pattern a selectable number of times along either or both axes. Horizontal stretching is achieved by clocking the shift register more slowly than the rate at which it is being read out. Vertical stretching is achieved by repeating the same pattern on each of a selectable number of consecutive lines. Varying the ratio of the stretching along the horizontal axis to the stretching along the vertical axis allows the aspect ratio of the grains of the pattern to be controlled. The values that are used to initialize the shift register can also be altered to achieve additional variation in the patterns generated. Two (or more) modifiable pseudo-random pattern generators can be used in combination with an array of selectable filters to provide a controllable noise pattern generator with coarse and fine pattern controls and selectable filtering of the output patterns produced.

Controllable pseudo random noise pattern generator for use in video

An adaptive rounder for avoiding truncation errors for digital video signal has a dither source that is modified by the bits of an integer portion of an input digital signal corresponding to the video signal. A dither signal from the dither source has a number of bits equal to a fractional portion of the input digital signal. The dither signal is added to the input digital signal and the result is truncated to produce an output digital signal having a number of bits equal to the integer portion.

Adaptive rounder for video signals

Video effects apparatus comprises a wipe generator for generating a wipe signal and a matte generator for generating a matte signal. The matte generator receives the wipe signal and the color represented by the matte signal is dependent on the wipe signal. First and second control signals are provided in response to the wipe signal. A first video mixer has signal input terminals connected to receive a first video signal and the matte signal respectively and a mix control input terminal connected to receive the first control signal as a mix control signal, and a second video mixer has signal input terminals connected to receive respectively a second video signal and the output signal of the first video mixer. The second mixer has a mix control input terminal connected to receive the second control signal as a mix control signal.

Apparatus for generating a video signal representing a field of

A mix effects based switcher architecture provides for processing of video signals with associated key signals throughout, the mix effects (M/E) banks within the switcher outputting both a composited video signal and a composited key signal for use by subsequent M/E banks. The outputs of the M/E banks may be combined together before being input to an output M/E bank. The output M/E bank provides a layered video signal with associated composited key signal at the output of the switcher.

Layered mix effects switcher architecture

A digital video effects apparatus comprises an input for receiving a digital input video signal representing the distribution of optical information over a video field, and a key signal generator for providing a digital key signal that defines an area of the video field. A mask signal generator provides a digital mask signal that defines at least a portion of said area of the video field. The digital mask signal is combined with the digital key signal to provide a modified digital key signal, and the input video signal is acted on in accordance with the modified key signal to provide an output video signal.

Digital video effects apparatus

Video signal processing apparatus comprises at least first and second source selectors each having a plurality of input terminals, for receiving a plurality of video signals respectively, and at least two output terminals. A set of video processors each have an input terminal and an output terminal. A processor selector is provided for connecting each source selector output terminal selectively to each video processor input terminal. First and second output devices each have a plurality of input terminals connected to the output terminals of the video processors respectively and also have an output terminal. Operator interfaces are connected to the processor selector for defining a first subset of video processors having their input terminals connected to the output terminals of the first source selector and a second subset of video processors having their input terminals connected to the output terminals of the second source selector. The operator interfaces are also connected to the first output device for selecting the output terminals of the first subset of video processors and to the second output device for selecting the output terminals of the second subset of video processors.

Video switcher system with modular architecture

A video switcher comprises a source selector having a plurality of input terminals for connection to a plurality of video sources respectively, and at least two output terminals. At least two processing channels each have an input terminal connected to an output terminal of the source selector and also have an output terminal. A video combiner has video input terminals connected to the output terminals of the processing channels and is operative to combine the output signals provided by the processing channels in dependence upon priority signals.

Video switcher with independent processing of selected video signals

Video mixer with multicolor boarder

A diagnostic system for a digital signal processor, having an input module, an output module and a plurality of successive processing modules defining a signal processing path, monitors various internal test points within each module. Any one of the test points may be connected to a diagnostic bus. The output of the diagnostic bus may be appropriately modified and input to the output module in lieu of the digital signal from the last processing module to provide a diagnostic display.

Diagnostic system for a digital signal processor

A digital wipe generator has a digital waveform generator to generate X and Y digital waveforms from a composite sync signal. A digital wipe solid generator processes the X and Y digital waveforms to produce a digital wipe solid waveform. The wipe solid generator has a circle generator using a square root function which preshifts the sum of the squares prior to access to a look-up table, and then post shifts the output of the look-up table by one-half the amount of the preshift to produce a desired curve pattern for the digital wipe solid waveform. The digital wipe solid waveform is input to mixer circuits where it is processed to produce an anti-aliased key signal for mixing external video signals, the anti-aliasing being based upon an interpolation/decimation scheme using fractional bits of the digital wipe solid waveform. The output of the mixer circuits is a desired wipe transition.

Digital wipe generator

A first pair of input data words represent two adjacent pixels on a first line of a first field of a video signal in interlaced format, a second pair of input data words represent two adjacent pixels of a first line of a second field of the video signal, and a third pair of input data words represent two adjacent pixels of a second line of the second field. The first and second lines of the second field are adjacent lines in that field and the first line of the first field is between the first and second lines of the second field. The positions on their respective lines of the pixels represented by the second and third pairs of input data words correspond to the positions on the first line of the first field of the pixels represented by the first pair of input data words. The first, second and third pairs of data words are read from memory, and are processed by interpolating among them to generate an output data word. The relative contributions to the output data word of the three pairs of input data words depend on whether an indication is provided that there is motion in the region of the frame in which the pixels represented by the second pair of input data words appear.

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Nevada City, CA, United States of America

John Abt