Audio directionality control for a multi-display switched video conferencing system

• US 8,289,362 B2
• Filed: 09/26/2007
• Issued: 10/16/2012
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Baird, Randall B.
• Primary Examiner(s): Ramakrishnaiah, Melur
• Application Number:
  US11/904,248
• Publication Number:
  US 20090079815A1
• Time in Patent Office: 1,847 Days
• Field of Search: 348 1401- 1416, 379/202.01
• US Class Current: 348/14.08
• CPC Class Codes: H04N 7/142 Constructional details of the terminal equipment, e.g. arrangements of the camera and the display
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q
• CPC Class Codes: H04N 7/15 Conference systems

Abstract

In one embodiment, a method includes setting a target value for each audio source received from a plurality of remote participants to a telepresence conference, the gain coefficient array feeding a mixer associated with a loudspeaker associated with a display. A gain increment value is then set for each audio source, the gain increment value being equal to a difference between the target value and a current gain coefficient, the difference being divided by N, where N is an integer greater than one that represents a number of increments. Then, for each audio source, and for each of N iterations, the gain increment value is added to a current gain coefficient to produce a new current gain coefficient that is loaded into the mixer, such that after the N iterations the new current gain coefficient is equal to the target value. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.

Claims

1. An apparatus comprising:

first and second video displays to display images of remote participants to a telepresence conference;

first and second loudspeakers respectively associated with the first and second video displays;

first and second audio mixers each of which is coupled to receive audio sources input from the remote participants, each of the first and second audio mixers being operable to apply a gain coefficient to each audio source, the first and second audio mixers being operable to produce first and second mixed audio outputs to the first and second loudspeakers, respectively; and

one or more processors to implement a finite state machine (FSM) comprising first, second, and third states that control the gain coefficient applied to each audio source by each of the first and second audio mixers, in the first state, which corresponds to a substantial silence or a background noise only, audio being suppressed or mixed as non-directional in the first and second mixed audio outputs;

in the second state, which corresponds to a loud, undisplayed participant, audio being mixed as non-directional in the first and second mixed audio outputs; and

in the third state, which corresponds to a loud, displayed participant, audio being mixed as directional with respect to either the first or second mixed audio outputs, depending on whether the first or second video displays an image of the loud, displayed participant.

2. The apparatus of claim 1 further comprising means for transitioning the first and second mixed audio outputs by changing the gain coefficient applied to each audio source by each of the first and second mixers from a current value to a target value responsive to a transition from the second state to the third state.

3. The apparatus of claim 2 wherein the means is further for computing a gain increment to be applied to each audio source by each of the first and second audio mixers during each of N iterations, where N is a number greater than 1.

4. The apparatus of claim 1 wherein the FSM further comprises a fourth state that corresponds to speech from an audio-only participant, in the fourth state the speech being mixed as non-directional in the first and second mixed audio outputs.

5. The apparatus of claim 1 wherein an audio source associated with a remote participant transitions from the first state to the second state when the remote participant starts talking.

6. The apparatus of claim 1 wherein an audio source associated with a remote participant transitions from the second state to the first state when the remote participant stops talking.

7. The apparatus of claim 1 wherein an audio source associated with a remote participant transitions from the second state to the third state responsive to the remote participant talking for a time duration that exceeds a predetermined time.

8. The apparatus of claim 1 wherein an audio source associated with a remote participant transitions from the third state to the first state when an image of the remote participant is replaced on either the first or second video display by another image.

9. The apparatus of claim 1 further comprising:

a third video display;

a third loudspeaker associated with the third video display;

and a third audio mixer which is coupled to receive the audio sources input from the remote participants, the third audio mixer being operable to apply a gain coefficient to each audio source and produce a third mixed audio output to the third loudspeaker; and

wherein the one or more processors control the gain coefficient applied to each audio source input to the third mixer in accordance with the FSM.

10. A method comprising:

setting, at a gain coefficient array, a target value for each audio source received from a plurality of remote participants to a telepresence conference, the gain coefficient array feeding a mixer associated with a loudspeaker associated with a display, each target value comprising a percentage of a particular audio source;

setting a gain increment value for each audio source, the gain increment value being equal to a difference between the target value and a current gain coefficient, the difference being divided by N, where N is an integer greater than one that represents a number of increments; and

for each audio source, and for each of N iterations, adding the gain increment value to a current gain coefficient to produce a new current gain coefficient that is loaded into the mixer, such that after the N iterations the new current gain coefficient is equal to the target value.

11. The method of claim 10 further comprising waiting a time period prior to the adding of the gain increment value to the current gain coefficient.

12. The method of claim 10 further comprising changing an image displayed on the display to that of a different remote participant.

13. The method of claim 12 wherein the target value for the audio source associated with the different remote participant is 100% or fully directional with respect to the loudspeaker and the display.

14. The method of claim 12 wherein the target value for an audio source that is not being displayed on the display is set equal to 100% divided by a number of mixers at a site of the telepresence conference that includes the mixer, the loudspeaker and the display.

15. The method of claim 12 wherein the target value for an audio source that is not being displayed on the display is set equal to 100% divided by a number of mixers at a site of the telepresence conference that includes the mixer, the loudspeaker and the display, plus a certain percentage where a remote participant associated with the audio source is predicted to be displayed on the display in the event the remote participant talks for a time duration greater than a predetermined period of time.

16. One or more computer-readable non-transitory storage media embodying logic this is operable when executed by one or more computer systems to:

set, at a gain coefficient array, a target value for each audio source received from a plurality of remote participants to a telepresence conference, the gain coefficient array feeding a mixer associated with a loudspeaker associated with a display, each target value comprising a percentage of a particular audio source;

set a gain increment value for each audio source, the gain increment value being equal to a difference between the target value and a current gain coefficient, the difference being divided by N, where N is an integer greater than one that represents a number of increments; and

for each audio source, and for each of N iterations, add the gain increment value to a current gain coefficient to produce a new current gain coefficient that is loaded into the mixer, after the N iterations the new current gain coefficient being equal to the target value.

17. The logic of claim 16 wherein the media, when executed, is further operable to wait a time period prior to adding the gain increment value to the current gain coefficient.

18. The logic of claim 16 wherein execution of the logic is triggered in response to a different remote participant image being displayed by the display.

19. The logic of claim 18 wherein the target value for the audio source associated with the different remote participant image is 100% or fully directional with respect to the loudspeaker and the display.

20. The logic of claim 18 wherein the target value for the audio source, where the audio source is not being displayed on the display, is set equal to 100% divided by a number of mixers at a site of the telepresence conference that includes the mixer, the loudspeaker and the display.