Method and apparatus for transmission of full frequency digital audio

• US 5,544,228 A
• Filed: 09/27/1993
• Issued: 08/06/1996
• Est. Priority Date: 09/27/1993
• Status: Expired due to Term

• Current Assignee: Disney Enterprises Incorporated (The Walt Disney Company)
• Original Assignee: The Walt Disney Company
• Inventors: Miller, Jeffrey S., Dempsey, Richard T., Wagner, Byron D., Johnson, Von W.
• Primary Examiner(s): Hofsass, Jefferey
• Assistant Examiner(s): TSANG, FAN S
• Application Number:
  US08/127,586
• Time in Patent Office: 1,044 Days
• Field of Search: 379/67, 379/93, 379/101, 379/100, 379/202, 379/88, 379/89, 379/102, 370/110.1, 370/62, 370/61, 395/244, 395/2.45, 395/2.48, 324/76.15, 324/76.24, 324/76.35, 324/76.42, 434/156, 434/157, 434/118, 434/185, 434/307, 434/308, 434/323, 434/362
• US Class Current: 379/67.1
• CPC Class Codes: H04Q 11/0435 Details

Abstract

The present invention is a method for transmitting full frequency digital audio signals over a network in real time and for providing access to a remote sound server. The present invention is preferably practiced using ISDN and is useful for remote casting auditions and for other communications. The present invention allows two or more sites on a network to communicate simultaneously. Live high-fidelity audio may be stored locally and/or transmitted to another site. At the other site, the audio may be stored and/or reproduced in high fidelity. Sound samples may be retrieved from a sound sample server and transmitted in high fidelity in real time over the network.

Claims

1. A system comprising:

a network for transmitting digital information;

a plurality of sites coupled to said network, said plurality of sites comprising;

an audio source for providing an analog audio input signal;

a speaker for reproducing an analog audio output signal;

analog-to-digital conversion means coupled to said audio source for converting said analog audio input signal to a digital audio input signal;

a data compression means coupled to said analog-to-digital conversion means to convert said digital audio input signal to a compressed digital audio input signal;

digital-to-analog conversion means coupled to said speaker for providing said analog audio output signal to said speaker;

a first network interface means coupled to said data compression means, said first network interface means for transmitting said compressed digital audio input signal to said network;

a second network interface means coupled to said network for receiving said compressed digital audio input signal from said network;

digital audio storage means coupled to said second network interface means;

wherein said analog audio input signal is converted by said analog-to-digital conversion means to said digital audio input signal, and wherein said digital audio input signal is converted to said compressed digital audio input signal and transmitted by said network to said digital audio storage means for storage therein, and wherein said digital audio storage means retrieves said compressed digital audio input signal, wherein said compressed digital audio input signal is converted to said analog audio output signal by said digital-to-analog conversion means, and wherein said speaker reproduces said analog audio output signal.

2. The system of claim 1 wherein said audio source comprises a microphone.

3. The system of claim 2 wherein said audio source further comprises recording equipment.

4. The system of claim 1 wherein said network is an ISDN.

5. The system of claim 1 wherein a codec with data compression capability comprises said analog-to-digital conversion means and said digital-to-analog conversion means.

6. The system of claim 4 wherein said network interface is an ISDN basic rate interface (BRI) terminal adapter (TA).

7. A system comprising:

an audio source for providing a first analog audio signal;

a computer for providing a first digital data signal;

a first analog-to-digital conversion means for converting said first analog audio signal to a first digital audio signal;

a first data compression means coupled to said first analog-to-digital conversion means to convert said first digital audio signal to a first compressed digital audio signal;

a first end of a telecommunication line coupled to said first data compression means for transmitting said first compressed digital audio signal and said first digital data signal;

a first digital-to-analog conversion means coupled to a second end of said telecommunication line for separating said first compressed digital audio signal and said first digital data signal and for converting said first compressed digital audio signal to a second analog audio signal, said second analog audio signal substantially identical to said first analog audio signal and having a frequency range substantially equal to a range of audible frequencies;

a sound server comprising a library of sound samples coupled to said first digital-to-analog conversion means for receiving said first digital data signal and for producing a third analog audio signal from said library of sound samples;

a second analog-to-digital conversion means coupled to said sound server for converting said third analog audio signal to a second digital audio signal;

a second data compression means coupled to said second analog-to-digital conversion means to convert said second digital audio signal to a second compressed digital audio signal, said second data compression means transmitting said second compressed digital audio signal over a transmission line;

a second digital-to-analog conversion means coupled to said first end of said telecommunications line for converting said second compressed digital audio signal to a fourth analog audio signal substantially identical to said third analog audio signal and having a frequency range substantially equal to a range of audible frequencies.

8. The system of claim 7 wherein said library of said sound samples comprises a library of character voice samples.

9. The system of claim 7 wherein said telecommunication line is an ISDN basic rate interface (BRI) line.

10. The system of claim 7 wherein a first codec comprises said first data compression means, said first analog-to-digital conversion means and said second digital-to-analog conversion means, and wherein a second codec comprises said second data compression means, said second analog-to-digital conversion means and said first digital-to-analog conversion means.

11. A method for using a telecommunication network for communicating audio signals comprising the steps of:

digitizing an analog audio input signal at a first site to provide a digital audio signal;

performing a data compression operation on said digital audio signal to provide a compressed digital audio signal;

communicating said compressed digital audio signal from said first site to a second site;

performing a data decompression operation on said compressed digital audio signal to provide a decompressed digital audio signal;

performing a digital-to-analog conversion operation on said decompressed digital audio signal to provide an analog audio output signal, said analog audio output signal being substantially identical to said analog audio input signal over a frequency range substantially equal to a range of audible frequencies;

communicating a digital data signal from said first site to said second site;

retrieving a stored sound sample from a computer at said second site;

communicating said stored sound sample digitally in real time from said second site to said first site.

12. The method of claim 11 wherein said step of communicating said compressed digital audio signal comprises transmitting said compressed digital audio signal over an ISDN basic rate interface (BRI) line.

13. The method of claim 12 wherein said step of communicating said digital data signal comprises transmitting said digital data signal over an ISDN basic rate interface (BRI) line.

14. The method of claim 11 wherein said step of performing said data compression operation has a compression ratio of 4:

1.

15. The method of claim 11 further comprising the steps of:

using a microphone for obtaining in audition performance containing a range of audible frequencies, said microphone outputting said analog audio input signal;

using said computer for producing a comparison image comparing said stored sound sample to said audition performance.

16. The method of claim 15 wherein said step of producing said comparison image further comprises the step of producing a sound spectrogram by said computer.

17. A method for electronically comparing an audition performance to a sound sample comprising the steps of:

accessing a database coupled to a local end of a communication network containing said sound sample;

electronically retrieving said sound sample from said database in real time;

obtaining said audition performance;

performing a data compression operation on said audition performance to obtain a compressed audition performance;

transmitting said compressed audition performance over said communication network to said local end of said communication network;

performing a data decompression operation on said compressed audition performance to obtain said audition performance;

producing a comparison image comparing said sound sample to said audition performance.

18. The method of claim 17 wherein said step of producing said comparison image comprises the steps of:

producing a first image representative of said sound sample; and

producing a second image representative of said audition performance.

19. The method of claim 18 wherein said step of producing said first image comprises a step of producing a first sound spectrogram and said step of producing said second image comprises a step of producing a second sound spectrogram.

20. The method of claim 18 wherein said step of producing said first image comprises a step of producing a first Fourier transform image and said step of producing said second image comprises a step of producing a second Fourier transform image.

21. The method of claim 17 wherein said step of producing said comparison image comprises a step of producing a differential or digital subtraction image derived from said sound sample and from said audition performance.

22. The method of claim 21 wherein said step of producing said comparison image comprises a step of producing a sound spectrogram.

23. The method of claim 21 wherein said step of producing said comparison image comprises a step of producing a Fourier transform image.

24. A system comprising:

an audio source for providing a first analog audio signal;

a computer for providing a first digital data signal;

a first analog-to-digital conversion means for converting said first analog audio signal to a first digital audio signal;

a first data compression means coupled to said first analog-to-digital conversion means to convert said first digital audio signal to a first compressed digital audio signal;

a first end of a telecommunication line coupled to said first data compression means for transmitting said first compressed digital audio signal and said first digital data signal;

a first digital-to-analog conversion means coupled to a second end of a telecommunication line for separating said first compressed digital audio signal and said first digital data signal and for converting said first compressed digital audio signal to a second analog audio signal, said second analog audio signal substantially identical to said first analog audio signal and having a frequency range substantially equal to a range of audible frequencies;

a sound server comprising a library of sound samples coupled to said first digital-to-analog conversion means for receiving said first digital data signal and for producing a third analog audio signal from said library of sound samples;

a second analog-to-digital conversion means coupled to said sound server for converting said third analog audio signal to a second digital audio signal;

a second data compression means coupled to said second analog-to-digital conversion means to convert said second digital audio signal to a second compressed digital audio signal, said second data compression means transmitting said second compressed digital audio signal over a transmission line;

a portable computer having a second digital-to-analog conversion means coupled to said first end of said telecommunications line for converting said second compressed digital audio signal to a fourth analog audio signal substantially identical to said third analog audio signal and having a frequency range substantially equal to a range of audible frequencies.