Audio processor

• US 6,141,597 A
• Filed: 09/08/1997
• Issued: 10/31/2000
• Est. Priority Date: 09/08/1997
• Status: Expired due to Term

• Current Assignee: Polycom Incorporated (HP Inc.)
• Original Assignee: Picturetel Corporation (HP Inc.)
• Inventors: Franklin, David M., Botzko, Stephen C.
• Primary Examiner(s): CHIN, VIVIAN C
• Application Number:
  US08/925,309
• Time in Patent Office: 1,149 Days
• Field of Search: 381/119, 381/23, 381/22, 379/202, 364/400.01, 700/94, 704/275, 704/500, 704/503
• US Class Current: 700/94
• CPC Class Codes: G10L 19/00 Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis in musical instruments G10H
• CPC Class Codes: G10L 2025/783 based on threshold decision
• CPC Class Codes: H04B 1/207 with an audio or audio/video bus for signal distribution H04B1/205 takes precedence
• CPC Class Codes: H04M 3/56 Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities video conference systems H04N7/15
• CPC Class Codes: H04M 3/568 audio processing specific to telephonic conferencing, e.g. spatial distribution, mixing of participants echo suppression in two-way loud-speaking telephone systems H04M9/02; sound field processing per se H04S7/30

Abstract

A method and apparatus for distributing audio signals from one of a plurality of audio sources to an output connect compressed audio signals from each one of the plurality of audio sources to an audio processor. Uncompressed audio signals are derived from the compressed audio signals. The compressed audio signal from one of the plurality of audio sources is selectively coupled to the output based upon the uncompressed audio signals. In a preferred embodiment, the compressed audio signal from one of the plurality of audio sources is coupled to the output selectively in accordance with speech information detected in the uncompressed audio signals from the plurality of audio sources. The method and apparatus include mixing, selectively, the uncompressed audio signals from the plurality of audio sources into a composite uncompressed audio signal; compressing the uncompressed composite signal into a corresponding compressed composite signal; and connecting the compressed composite signal or the selected one of the compressed audio signals to the output selectively in accordance with the uncompressed audio signals. In a preferred embodiment of the invention, the compressed composite signal is fed to the output when speech audio signals are detected from more than one source and the selected one of the compressed audio signals is coupled to the output when speech is detected from only one of the sources.

Claims

1. A method for distributing audio signals from one of a plurality of audio sources to an output, comprising the steps of:

receiving compressed audio signals from each one of the plurality of audio sources at an audio processor;

decompressing the compressed received audio signals;

coupling the compressed audio signal from one of the plurality of audio sources to the output, selectively, based upon speech information detected in the uncompressed audio signals from the plurality of audio sources;

mixing selected ones of the uncompressed audio signals, based upon said speech information, from the plurality of audio sources into a uncompressed composite audio signal;

compressing the uncompressed composite signal into a corresponding compressed composite signal; and

coupling the compressed composite signal to the output when speech audio signals are detected from more than one source and coupling the selected one of the compressed audio signals to the output when speech is detected from only one of the sources.

2. A method of distributing audio signals from one of a plurality of audio sources to an output, comprising the steps of:

receiving compressed audio signals from each one of the plurality of audio sources at an audio processor;

decompressing the compressed received audio signals;

coupling one of the plurality compressed audio signal from one of the plurality of audio sources to the output selectively based upon the uncompressed audio signals from the plurality of audio sources;

mixing, selectively, the uncompressed audio signals from the plurality of audio sources to generate a uncompressed composite audio signal whenever at least two audio sources are active, and

connecting either the uncompressed composite signals or the selected one of the compressed audio signals to the output selectively based upon the uncompressed audio signals.

3. The method recited in claims 2 further comprising the steps of

determining from the uncompressed audio signals the number of audio sources producing a predetermined type of audio signal;

and

said connecting step comprises connecting either the uncompressed composite signal or the selected one of the compressed audio signals to the output selectively based upon the determined number of audio sources.

4. The method recited in claim 3 wherein the predetermined type of audio signal is speech.

5. The method recited in claim 4 wherein the selected one of the compressed audio signals is coupled to the output when the determined number of speech producing sources is one.

6. An audio processor for distributing audio signals from one of a plurality of audio sources to an output, comprising:

a switch, connected to compressed audio signals from each one of the plurality of audio sources, for coupling one of the plurality of compressed audio signals to the output selectively in accordance with a control signal;

a selector connected to the uncompressed audio signals, derived from the compressed audio signals, from the plurality of audio sources, for producing the control signal based upon speech information detected in the uncompressed audio signals from the plurality of audio sources;

a mixer for selectively combining the uncompressed audio signals from the plurality of audio sources into an uncompressed composite audio signal;

an encoder connected to the uncompressed composite signals, for producing a corresponding compressed composite signal; and

a selector for coupling the compressed composite signal to the output when speech audio signals are detected from more than one source and for coupling the selected one of the compressed audio signals to the output when speech is detected from only one of the sources.

7. An audio processor for distributing audio signals from one of a plurality of audio sources to an output, said processor, comprising:

a switch connected to compressed audio signals from each one of the plurality of audio sources, for coupling one of the plurality of compressed audio signals to the output selectively in accordance with a control signal;

a selector fed by the uncompressed audio signals, derived from the compressed audio signals, from the plurality of audio sources, for producing the control signal based upon the uncompressed audio signals from the plurality of audio sources;

a mixer for selectively combining the uncompressed audio signals from the plurality of audio sources into an uncompressed composite audio signal;

an encoder, connected to the uncompressed composite signal, for producing a corresponding compressed composite signal; and

a second selector for coupling either the selected one of the compressed audio signals or the compressed composite signal to the output, based upon the uncompressed audio signals.

8. An audio processor for distributing audio signals from one of a plurality of audio sources to an output, said processor, comprising:

a switch connected to compressed audio signals from each one of the plurality of audio sources, for coupling one of the plurality of compressed audio signals to the output selectively in accordance with a control signal;

a selector fed by the uncompressed audio signals, derived from the compressed audio signals, from the plurality of audio sources, for producing the control signal based upon the uncompressed audio signals from the plurality of audio sources;

a mixer for selectively combining the uncompressed audio signals from the plurality of audio sources into an uncompressed composite audio signal;

an encoder, connected to the uncompressed composite signal, for producing a corresponding compressed composite signal; and

a second selector for determining from the uncompressed audio signals the number of audio sources producing a predetermined type of audio signal and coupling either the selected one of the compressed audio signals or the compressed composite signal to the output, selectively, based upon the predetermined type of audio signal.

9. An audio processor for distributing audio signals from one of a plurality of audio sources to an output, said processor, comprising:

a switch connected to compressed audio signals from each one of the plurality of audio sources, for coupling one of the plurality of compressed audio signals to the output selectively in accordance with a control signal;

a selector fed by the uncompressed audio signals, derived from the compressed audio signals, from the plurality of audio sources, for producing the control signal based upon the uncompressed audio signals from the plurality of audio sources;

a mixer for selectively combining the uncompressed audio signals from the plurality of audio sources into an uncompressed composite audio signal;

an encoder, connected to the uncompressed composite signal, for producing a corresponding compressed composite signal; and

a second selector for determining from the uncompressed audio signals the number of audio sources producing a predetermined type of audio signal and for coupling either the selected one of the compressed audio signals or the compressed composite signal to the output, selectively based upon the predetermined type of audio signal,

wherein the predetermined type of audio signal is speech.

10. An audio processor for distributing audio signals from one of a plurality of audio sources to an output, said processor, comprising:

a switch connected to compressed audio signals from each one of the plurality of audio sources, for coupling one of the plurality of compressed audio signals to the output selectively in accordance with a control signal;

a selector fed by the uncompressed audio signals, derived from the compressed audio signals, from the plurality of audio sources, for producing the control signal based upon the uncompressed audio signals from the plurality of audio sources;

a mixer for selectively combining the uncompressed audio signals from the plurality of audio sources into an uncompressed composite audio signal;

an encoder, connected to the uncompressed composite signal, for producing a corresponding compressed composite signal; and

a second selector for determining from the uncompressed audio signals the number of audio sources producing a predetermined type of audio signal and for coupling either the selected one of the compressed audio signals or the compressed composite signal to the output selectively in accordance with the predetermined type of audio signal and determined by the number of audio sources producing such predetermined type of audio signal.