Acoustic echo canceller clock compensation
First Claim
1. An acoustic echo cancellation method for conference audio, comprising:
- obtaining far-end audio for output to a loudspeaker having a first clock;
obtaining near-end audio with a microphone having a second clock;
performing acoustic echo cancellation with the far-end and near-end audio;
cross-correlating an acoustic echo estimate of the far-end signal with the near-end signal; and
adjusting the far-end audio used for the acoustic echo cancellation by a factor relating first and second conversion rates of the first and second clocks based on the cross-correlation.
10 Assignments
0 Petitions
Accused Products
Abstract
A conferencing endpoint uses acoustic echo cancellation with clock compensation. Receiving far-end audio to be output by a local loudspeaker, the endpoint performs acoustic echo cancellation so that the near-end audio capture by a microphone will lack echo of the far-end audio output from the loudspeaker. The converters for the local microphone and loudspeaker may have different clocks so that their sample rates differ. To assist the echo cancellation, the endpoint uses a clock compensator that cross-correlates an echo estimate of the far-end audio and the near-end audio and adjusts a sample rate conversion factor to be used for the far-end audio analyzed for echo cancellation.
40 Citations
39 Claims
-
1. An acoustic echo cancellation method for conference audio, comprising:
-
obtaining far-end audio for output to a loudspeaker having a first clock; obtaining near-end audio with a microphone having a second clock; performing acoustic echo cancellation with the far-end and near-end audio; cross-correlating an acoustic echo estimate of the far-end signal with the near-end signal; and adjusting the far-end audio used for the acoustic echo cancellation by a factor relating first and second conversion rates of the first and second clocks based on the cross-correlation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A non-transitory machine-readable medium storing program instructions for causing a programmable control device to perform an acoustic echo cancellation method for conference audio, the method comprising:
-
obtaining far-end audio for output to a loudspeaker having a first clock; obtaining near-end audio with a microphone having a second clock; performing acoustic echo cancellation with the far-end and near-end audio; cross-correlating an acoustic echo estimate of the far-end signal with the near-end signal; and adjusting the far-end audio used for the acoustic echo cancellation by a factor relating first and second conversion rates of the first and second clocks based on the cross-correlation. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
-
-
13. An acoustic echo cancellation method for conference audio, comprising:
-
obtaining far-end audio for output to a loudspeaker having a first clock with a first conversion sample rate; obtaining near-end audio with a microphone having a second clock with a second conversion sample rate; adaptively filtering the far-end audio relative to the near-end audio; outputting output audio for transmission to the far-end, the output audio having the adaptively filtered audio subtracted from the near-end audio; cross-correlating the adaptively filtered audio and the near-end audio; and adjusting the obtained far-end audio by a factor relating the first and second conversion sample rates based on the cross-correlation. - View Dependent Claims (31, 32, 33, 34)
-
-
14. A non-transitory machine-readable medium storing program instructions for causing a programmable control device to perform an acoustic echo cancellation method for conference audio, the method comprising:
-
obtaining far-end audio for output to a loudspeaker having a first clock with a first conversion sample rate; obtaining near-end audio with a microphone having a second clock with a second conversion sample rate; adaptively filtering the far-end audio relative to the near-end audio; outputting output audio for transmission to the far-end, the output audio having the adaptively filtered audio subtracted from the near-end audio; cross-correlating the adaptively filtered audio and the near-end audio; and adjusting the obtained far-end audio by a factor relating the first and second conversion sample rates based on the cross-correlation. - View Dependent Claims (35, 36, 37, 38, 39)
-
-
15. A conferencing endpoint, comprising:
-
a microphone capturing near-end audio based on a first clock; a loudspeaker outputting far-end audio based on a second clock; a network interface receiving the far-end audio and outputting output audio; and a processing unit operatively coupled to the microphone, the loudspeaker, and the network interface and configured to; perform acoustic echo cancellation between the near-end and far-end audio; output the acoustic echo cancelled audio as the output audio with the network interface; cross-correlate an acoustic echo estimate of the far-end signal with the near-end signal; and adjust the far-end audio used for the acoustic echo cancellation by a factor relating first and second conversion sample rates of the first and second clocks based on the cross-correlation. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
-
Specification