Visuasl dynamics management for audio instrument

• US 5,524,060 A
• Filed: 02/14/1994
• Issued: 06/04/1996
• Est. Priority Date: 03/23/1992
• Status: Expired due to Term

• Current Assignee: Avid Technology Incorporated
• Original Assignee: Euphonix Incorporated (Avid Technology Incorporated)
• Inventors: Wiser, Philip R., Fay, Edward G., Silfvast, Scott W., Silfvast, Robert D.
• Primary Examiner(s): Isen, Forester W.
• Assistant Examiner(s): Mei, Xu
• Application Number:
  US08/195,982
• Time in Patent Office: 841 Days
• Field of Search: 381/119, 381/104, 381/106, 381/161, 345/134, 345/135, 345/145, 345/167, 345/173, 345/157, 364/188, 395/100, 395/104, 395/106, 395/155, 395/159
• US Class Current: 381/104
• CPC Class Codes: H03G 3/00 Gain control in amplifiers or frequency changers
• CPC Class Codes: H03G 3/001 Digital control of analog signals
• CPC Class Codes: H03G 7/005 using discontinuously variable devices, e.g. switch-operated
• CPC Class Codes: H03G 7/007 of digital or coded signals
• CPC Class Codes: H04H 60/04 Studio equipment; Interconnection of studios

Abstract

A digital audio gain control system has an operator interface with a CPU, RAM storage, and input devices for a user to store transfer characteristics relating gain to be applied to an incoming audio signal to the signal strength of that incoming signal. A communication link allows the transfer characteristic function to be sent to a RAM in a separate patchable amplifier unit having a DSP and RAM, and level detection circuitry for monitoring the signal strength of an incoming audio signal and applying gain according to the transfer characteristic communicated to the on-board RAM. The amplifier unit also sends operating information back to the operator interface, where operation may be displayed to aid an operator in adjusting the function.

Claims

1. In a system for controlling output signal level as a function of input signal level for an automatic gain-control amplifier, the system including a transfer function and at least one time constant for determining gain to be applied to the input signal, a display comprising:

the transfer function as a static curve of gain plotted against input signal strength or of output signal strength plotted against input signal strength; and

a dynamic cursor object displayed on the area of the curve of the transfer function;

wherein the dynamic cursor object is positioned on the area of the curve of the transfer function in substantially real time according to the input signal strength, the transfer function, and the time constant.

2. A display as in claim 1 wherein multiple time constants are utilized in displaying the dynamic cursor object.

3. A display as in claim 2 wherein the time constants include attack, release, and hold times.

4. A display as in claim 1 further comprising a dynamic abscissa bar and a dynamic ordinate bar in conjunction with the static curve and the dynamic cursor object, and the position of the dynamic abscissa and ordinate bars is updated in substantially real time.

5. A display as in claim 1 wherein dual abscissa and ordinate bars are displayed, tracking dynamic level of stereo input and output channels.

6. A display as in claim 1 further comprising an array of control panels displaying parameters for the transfer function and time constant values.

7. An operator interface for controlling an output signal of an automatic-gain-control amplifier system relative to an input signal, a transfer function, and at least one time constant, and for displaying the dynamic result of applied control, the operator interface comprising:

input apparatus for an operator to enter values for control variables;

a display; and

computerized control circuitry coupled to the display and the input apparatus and adapted for executing the transfer function and for driving the display according to prestored control routines and measured values of input signal strength;

wherein the computerized control circuitry displays a control function on the display as a static curve of gain plotted against input signal strength or of output signal strength plotted against input signal strength, and also displays on the area of the control function a dynamic cursor object, the dynamic cursor object positioned on the area of the curve of the transfer function in substantially real time according to the input signal strength, the transfer function, and the time constant.

8. An operator interface as in claims 7 wherein multiple time constants are utilized in displaying the dynamic cursor object.

9. An operator interface as in claim 8 wherein the time constants include attack, release, and hold times.

10. An operator interface as in claim 7 further comprising a dynamic abscissa bar and a dynamic ordinate bar in conjunction with the static curve and the dynamic cursor object, and the position of the dynamic abscissa and ordinate bars is updated in substantially real time.

11. An operator interface as in claim 10 wherein dual abscissa and ordinate bars are displayed, tracking dynamic level of stereo input and output channels.

12. An operator interface as in claim 7 further comprising an array of control panels displaying parameters for the transfer function and time constant values.

13. An operator interface as in claim 7 wherein the computerized control circuitry executes the control function and displays the dynamic cursor object according to measured values of a tracked key audio signal rather than measured values of input signal strength.

14. An operator interface as in claim 13 further comprising a switching apparatus for switching control between measured values of input signal strength and a the tracked key audio signal.

15. An operator interface as in claim 7 wherein the input signal is a stereo signal, and the computerized control circuitry executes the transfer characteristic and displays the dynamic cursor object according to the greater of the signal strengths of the stereo inputs.

16. In an automatic-gain-control amplifier system including a transfer characteristic and at least one time constant for applying the transfer characteristic, a method for displaying information to an operator, comprising steps of:

(a) displaying the transfer characteristic on a display screen as a static curve of gain plotted against input signal strength or of output signal strength plotted against input signal strength; and

(b) displaying a dynamic cursor object in the same area as the static curve;

wherein the position of the dynamic cursor object is updated in substantially real time according to the input signal strength, the transfer characteristic, and the time constant.

17. The method of claim 16 wherein multiple time constants are associated with the transfer characteristic for applying the transfer characteristic to the input signal strength.

18. The method of claim 17 wherein the multiple time constants include attack, release, and hold times.

19. The method of claim 16 including a step for displaying at least one of a dynamic abscissa or a dynamic ordinate bar, wherein the amplitude of the bar display is updated in substantially real time.

20. The method of claim 16 wherein the transfer characteristic and the dynamic cursor object are displayed according to a tracked key audio signal rather than the input signal strength.

21. The method of claim 16 wherein the input signal is a stereo input, and the computerized control circuitry displays the dynamic cursor object according to the greater of the signal strengths of the stereo inputs.