Tektronix, Inc.

National Broadcasting Company, Inc.

Robert W Parish

Scott E Zink

Daniel G Baker

Bruce J Penney

Michael S Overton

Steven Douglas Maurer

Evan Albright

Thomas E Chabreck

Benjamin T Humble

Steven Orland

Embodiments of the invention are directed to a system for generating video test pattern signals from definitions contained in a text-based definition file. The definition file allows the user to create generic definitions for test signals that can be interpreted to create test signals in a variety of formats, raster sizes, color spaces, sample structures, frame modes, and bit depths. A parametric generator uses one or more engines to then generate the desired test pattern from the definition file.

System for generating text defined test patterns

Image alias rejection when converting a high resolution rasterized waveform to a lower resolution rasterized waveform for display uses a statistical filter. The statistical filter provides a shaped probability density function either by combining the outputs of multiple random number generators, such as linear feedback shift registers, or by using a corresponding look-up table to produce a dither signal. The statistical filter may be applied to one or both of the dimensional values for each data point of the high resolution rasterized waveform by combining the dimensional values with the dither signal. The resulting filtered dimensional values may then be subsampled, such as by truncation, to produce values for a lower resolution rasterized waveform display.

Image alias rejection using shaped statistical filtering

A serial digital video data analyzer combines a co-processor capable of handling the serial digital video data stream bit rate with a microprocessor operating at a slower bit rate. The co-processor includes a video feature detection/decision module that identifies specified errors or features from the serial digital video data stream and freezes the portion of the serial digital video data stream around such feature/error in a video data store. The co-processor may also insert a cursor into the serial digital video data stream prior to display on a monitor to indicate the position of indicated errors. The acquired serial digital video data is transferred to the microprocessor for an initial determination as to whether further processing is required. If further processing is required, the results are displayed as a report and the microprocessor interacts with the co-processor to acquire additional data needed for processing or to indicate that the processing is completed and the co-processor should continue its feature detection/decision process. In this way any desired analysis of the serial digital video data stream may be performed.

Digital video error analyzer

A return-loss detector for a serial digital signal source uses a return-loss bridge circuit to exploit the broadband spectral characteristics of a serial digital signal from the signal source to monitor the termination conditions of a system being driven. A differential pair of serial digital signals from the source are input to the bridge circuit having a reference termination in one leg and the system termination in the other. A broadband detector is used at the output of the bridge circuit to generate an error signal, which is measured by a detector or metering circuit. The measured signal may be displayed as a value in dB or may be input to a comparator to provide an alarm or warning signal to an operator.

Return-loss detection for serial digital source

A method for timing audio and video component signals of a television signal with coincidental markers generates a field pulse every Nth field of the televison signal at the transmitter. The duration of the field pulse is approximately one video field, and is ued to enable an audio tone generator for the one video field and to switch a distinctive video signal, such as a flat video signal, into the video component signal for the one video field. At the receiver the two component signals are input through a synchronizer to a waveform display device, such as an oscilloscope, to observe the time differential between the two markers in the audio and video component signals. The audio component signal is delayed by the synchronizer until the markers are again in time conicidence as at the transmitter.

Timing audio and video signals with coincidental markers

A heterodyne color signal recognition circuit generates an error signal for each horizontal line of an input video signal for which the phase relationship of the horizontal sync pulse and color subcarrier burst exceeds a given phase relationship by a predetermined tolerance. The error signals are summed over a video field to produce a preliminary non-direct color signal for the video field. Preliminary non-direct color signals for successive video fields are digitally filtered to generate a non-direct color signal indicative of a heterodyne color signal source, the non-direct color signal being used to automatically switch in a time base corrector between the input video signal and further video processing.

Growing community of inventors

Gaston, OR, United States of America

Robert W Parish