Methods and apparatus to determine a state of a media presentation device

Patent metadata

Field	Value
Publication number	US-2016295279-A1
Application number	US-201514926885-A
Country	US
Kind code	A1
Filing date	Oct 29, 2015
Priority date	Apr 3, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

Methods and apparatus to determine a state of a media presentation device are disclosed. Example disclosed methods include generating a first set of weighted coefficients based on first audio received by first and second microphones at a first time. Example disclosed methods include generating a second set of weighted coefficients based on second audio received by the first and second microphones at a second time after the first time. Example disclosed methods include comparing the first set of coefficients and the second set of coefficients to generate a similarity value. Example disclosed methods include, when the similarity value satisfies a threshold, determining that the media presentation device is in a first state. Example disclosed methods include, when the similarity value does not satisfy the threshold, determining that the media presentation device is in a second state.

First claim

1 . A method of determining a state of a media presentation device, the method comprising:
generating a first set of weighted coefficients based on first audio received by first and second microphones at a first time; generating a second set of weighted coefficients based on second audio received by the first and second microphones at a second time after the first time; comparing the first set of coefficients and the second set of coefficients to generate a similarity value; when the similarity value satisfies a first threshold, determining that the media presentation device is in a first state; when the similarity value does not satisfy the first threshold, determining that the media presentation device is in a second state; and controlling a metering device based on the state of the media presentation device.

2 . The method of claim 1 , further including:
when the media presentation device is in the first state, extracting a watermark from the second audio.

3 . The method of claim 1 , wherein the generating first and second sets of weighted coefficients include applying an echo cancellation algorithm using a finite impulse response filter to generate the first set of weighted coefficients and to generate the second set of weighted coefficients.

4 . The method of claim 1 , wherein the first state includes an on state, and wherein the second state includes an off state.

5 . The method of claim 1 , further including:
applying the third set of weighted coefficients to one or more samples of a third audio received at the first microphone to provide a filter output; comparing the filter output to a sample of the third audio received at the second microphone to generate an error signal; and when the error signal exceeds a second threshold, adjusting the first set of weighted coefficients based on the error signal.

6 . The method of claim 5 , wherein the error signal includes X e (n)=X d (n)−Y O (n), wherein X d (n) represents an audio sample and Y 0 (n) represents a summed filter output of multiple audio samples and n is an iteration index, and wherein the first set of weighted coefficients is adjusted based on the error signal by W m (n+1)=W m (n)+μX e X m (n), wherein W m (n+1) and W m are weight coefficients and μ is a learning factor.

7 . The method of claim 5 , wherein comparing the filter output to a sample of the third audio received at the second microphone to generate an error signal further includes subtracting the filter output from the sample of the third audio received at the second microphone to generate the error signal.

8 . The method of claim 1 , wherein comparing the first set of coefficients and the second set of coefficients to generate a similarity value further includes calculating a dot product between the first set of coefficients and the second set of coefficients to generate the similarity value.

9 . A tangible computer readable storage medium having instruction that, when executed, cause a machine to:
generate a first set of weighted coefficients based on first audio received by first and second microphones at a first time; generate a second set of weighted coefficients based on second audio received by the first and second microphones at a second time after the first time; compare the first set of coefficients and the second set of coefficients to generate a similarity value; when the similarity value satisfies a first threshold, determine that the media presentation device is in a first state; when the similarity value does not satisfy the first threshold, determine that the media presentation device is in a second state; and control a metering device based on the state of the media presentation device.

10 . The computer readable storage medium of claim 9 , having instructions that, when executed, cause the machine to, when the media presentation device is in the first state, extract a watermark from the second audio.

11 . The computer readable storage medium of claim 9 , having instructions that, when executed, cause the machine to generate first and second sets of weighted coefficients by applying an echo cancellation algorithm using a finite impulse response filter to generate the first set of weighted coefficients and to generate the second set of weighted coefficients.

12 . The computer readable storage medium of claim 9 , wherein the first state includes an on state, and wherein the second state includes an off state.

13 . The computer readable storage medium of claim 9 , having instructions that, when executed, cause the machine to:
apply the third set of weighted coefficients to one or more samples of a third audio received at the first microphone to provide a filter output; compare the filter output to a sample of the third audio received at the second microphone to generate an error signal; and when the error signal exceeds a second threshold, adjust the first set of weighted coefficients based on the error signal.

14 . The computer readable storage medium of claim 13 , wherein the error signal includes X e (n)=X d (n)−Y O (n), wherein X d (n) represents an audio sample and Y 0 (n) represents a summed filter output of multiple audio samples and n is an iteration index, and wherein the first set of weighted coefficients is adjusted based on the error signal by W m (n+1)=W m (n)+μX e X m (n), wherein W m (n+1) and W m are weight coefficients and μ is a learning factor.

15 . The computer readable storage medium of claim 13 , wherein the instructions, when executed, cause the machine to compare the filter output to a sample of the third audio received at the second microphone to generate an error signal by subtracting the filter output from the sample of the third audio received at the second microphone to generate the error signal.

16 . The computer readable storage medium of claim 9 , wherein the instructions, when executed, cause the machine to compare the first set of coefficients and the second set of coefficients to generate a similarity value by calculating a dot product between the first set of coefficients and the second set of coefficients to generate the similarity value.

17 . An apparatus comprising:
a metering device including a processor programmed to: generate a first set of weighted coefficients based on first audio received by first and second microphones at a first time; generate a second set of weighted coefficients based on second audio received by the first and second microphones at a second time after the first time; compare the first set of coefficients and the second set of coefficients to generate a similarity value; when the similarity value satisfies a first threshold, determine that the media presentation device is in a first state; when the similarity value does not satisfy the first threshold, determine that the media presentation device is in a second state; and control a metering device based on the state of the media presentation device.

18 . The apparatus of claim 17 , wherein the metering device is to generate the first and second sets of weighted coefficients by applying an echo cancellation algorithm using a finite impulse response filter to generate the first set of weighted coefficients and to generate the second set of weighted coefficients.

19 . The apparatus of claim 17 , wherein the first state includes an on state, and wherein the second state includes an off state.

20 . The apparatus of claim 17 , wherein the metering device is to:
apply the third set of weighted coefficients to one or m

Assignees

• Nielsen Co Us Llc

Inventors

• Srinivasan Venugopal
• Lee Morris
• Davis Jeremey M

Classifications

• H04H2201/90

  characterised by the use of signatures · CPC title

• H04H60/37

  for identifying segments of broadcast information, e.g. scenes or extracting programme ID · CPC title

• H04H2201/50

  characterised by the use of watermarks · CPC title

• H04N21/4394

  involving operations for analysing the audio stream, e.g. detecting features or characteristics in audio streams (arrangements characterised by components specially adapted for monitoring, identification or recognition of audio in broadcast systems H04H60/58) · CPC title

• H04N21/8106

  involving special audio data, e.g. different tracks for different languages · CPC title