Abstract: A method for performing a surround audio compatibility assessment on a plurality of original surround channels is described herein. A surround audio compatibility assessment system accepting original surround signals is also described herein.

Abstract: A surround audio dialog balance assessment method, apparatus, and system as disclosed herein is an audio monitor or is associated with an audio monitor. Preferred surround audio dialog balance assessment methods, apparatuses, and systems automate the process of monitoring audio signals through a broadcast chain.

Abstract: A method for performing a surround audio compatibility assessment on a plurality of original surround channels is described herein. A surround audio compatibility assessment system accepting original surround signals is also described herein.

Abstract: Methods and apparatus are disclosed for approximating an MDCT coefficient of a block of windowed sinusoid having a defined frequency, the block being multiplied by a window sequence and having a block length and a block index. A finite trigonometric series is employed to approximate the window sequence. A window summation table is pre-computed using the finite trigonometric series and the defined frequency of the sinusoid. A block phase is computed for each block with the defined frequency, the block length and the block index. An MDCT coefficient is approximated by the dot product of a phase vector computed using the block phase with a corresponding row of the window summation table.

Abstract: An intelligent solo-mute switching system for an audio signal processing device having a plurality of channels. A plurality of multi-throw momentary switches are monitored by a switch interface to detect at least three switch events. A channel state controller responds to the at least three switch events detected by the switch interface in directing a channel gain matrix to govern the plurality of channels.

Abstract: Coded test signals in two or more distinct coding formats are applied sequentially to the equipment under test (EUT) according to a test sequence. The ordering, timing and source characteristics of the coded test signals are fully programmable. The output of the EUT is analyzed to verify proper decoding and detect audible artifacts. A means for comparing recorded test events allows a test engineer to detect failure modes of the autodetection system in the EUT.

Abstract: Methods and apparatus are disclosed for approximating an MDCT coefficient of a block of windowed sinusoid having a defined frequency, the block being multiplied by a window sequence and having a block length and a block index. A finite trigonometric series is employed to approximate the window sequence. A window summation table is pre-computed using the finite trigonometric series and the defined frequency of the sinusoid. A block phase is computed for each block with the defined frequency, the block length and the block index. An MDCT coefficient is approximated by the dot product of a phase vector computed using the block phase with a corresponding row of the window summation table.

Abstract: An intelligent solo-mute switching system for an audio signal processing device having a plurality of channels. A plurality of multi-throw momentary switches are monitored by a switch interface to detect at least three switch events. A channel state controller responds to the at least three switch events detected by the switch interface in directing a channel gain matrix to govern the plurality of channels.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal. In one embodiment, the measurement equipment senses the presence of the test signal by comparing the received spectrum to a pair of templates whose shapes are determined by the test signal spectrum.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal. The multitone test signals a unique combination which is extracted at the output for identifying the source, or location, of the test signals.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A method and apparatus for fast response and distortion measurement of a signal transfer device. A computer processor generates a multitone test signal of predetermined duration and stores it in a memory. The test signal is read out, converted to analog form, if necessary, and applied to the input of a device under test. The output produced by the device under test in response to the test signal is acquired and digitized, if necessary, and a Fast Fourier Transform is performed on the acquired data to determine its spectral characteristics. Frequency response, harmonic distortion, intermodulation distortion, phase distortion, wow and flutter and other signal transfer characteristics are measured by the CPU by analysis of the output signal.

Abstract: A master-slave processor human interface system. An electronic device, a slave processor for controlling the electronic device and performing certain computational functions, a master processor for controlling the slave processor, an input device and an output device associated with the master processor, and an information storage device are provided. Individual slave processor programs are selected, retrieved from the information storage device, and loaded into the slave processor for implementing corresponding functions of the slave processor and electronic device, while a single master processor program which adapts itself to the selected slave processor program accepts input data and operational selections and displays output information according to a predetermined spatial arrangement for each such function, thereby providing the human interface.

Abstract: A method and apparatus for testing a digital signal processing system for the occurrence of bit errors. A mathematically-predictable test signal is applied to the input of a digital signal processing system The test signal components are removed from the output signal of the system by filtering, curve fitting or other techniques, leaving a resultant signal. The peak amplitude of the resultant signal is measured as an indication of the occurrence of errors. A time integrated measure of the resultant signal is made as an indication of the amount of noise and distortion artifacts. The peak amplitude is compared to a reference or the time integrated measure to identify errors. A histogram of the resultant signal amplitude may also be produced.

Abstract: A tunable bandpass filter system and filtering method wherein the bandwidth of a tunable bandpass filter is adjusted as a function of the fundamental frequency of an input signal. Either a constant bandwidth or a constant quality factor tunable bandpass filter may be used. The center frequency of the tunable bandpass filter is adjusted in direct proportion to the product of the fundamental frequency and the number of a selected harmonic thereof. In the case of a constant bandwidth filter the bandwidth is adjusted in direct proportion to the quotient of the fundamental frequency divided by a selected filter quality factor. In the case of a constant quality factor filter, the bandwidth is indirectly controlled by adjusting the center frequency while adjusting the quality factor in inverse proportion to the harmonic number. The output amplitude of the filter is measured to determine the amount of distortion in the input signal. The fundamental frequency may be determined by measuring the input signal.

Abstract: A hybrid form digital filter. A digital filter is provided wherein the zeros of its transfer function are provided by a direct form digital filter portion and the poles of the transfer function are provided by a normal form digital filter portion. The hybrid filter provides truncation noise and stability characteristics like those of a normal form digital filter, but its filter coefficients may be calculated more rapidly than those for a normal form digital filter having the same transfer function, thereby enabling the coefficients to be calculated in real time for tuning the filter. While the preferred embodiment is a second order hybrid digital filter, the same principles are applicable to higher order digital filters as well.

Abstract: A method and circuit for reducing the effect of variations in resistances within a multiplying digital-to-analog converter. A first resistor is connected at one end to the feedback resistor of the MDAC, the other end providing a compensated circuit input. A second resistor is connected from the MDAC input to the feedback resistor. The MDAC output to which the feedback resistor is internally connected is connected to the MDAC reference connection, the other output providing a compensated circuit output. The first and second resistors are chosen such that the product of their resistances is equal to the product of the feedback resistance times the MDAC input resistance.