Auxiliary channel masking in an audio signal

Abstract

A method is provided for embedding data into an audio signal and determining data embedded into an audio signal. In the method for embedding data into an audio signal, the audio signal is based on a first set of data and includes a phase component. The method modifies at least a portion of the phase component of the audio signal to embed a second set of data into the audio signal. The modified audio signal can be made to differ with respect to the audio signal in a manner at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data depending on the extent that the phase component of the audio signal is modified. In the method for determining data embedded into an audio signal, the audio signal is based on a first set of data of an original audio signal and includes a phase component. The method determines a second set of data embedded into the audio signal based on the phase component of the audio signal. The audio signal differs with respect to the original audio signal in a manner that is at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data.

1 . A method for embedding data into an audio signal, the audio signal being based on a first set of data and including a phase component, the method comprising: 
 modifying at least a portion of the phase component of the audio signal to embed a second set of data into the audio signal,    wherein the modified audio signal can be made to differ with respect to the audio signal in a manner at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data depending on the extent that the phase component of the audio signal is modified.    
   
   
       2 . The method of  claim 1 , wherein at least one of {i) the first set of data and (ii) the second set of data includes at least one of audio data, text data, video data, image data, and multimedia data.  
   
   
       3 . The method of  claim 1 , wherein the second set of data includes encrypted data.  
   
   
       4 . The method of  claim 1 , wherein the second set of data includes at least one of authentication data, content enhancement data, and distribution control data.  
   
   
       5 . The method of  claim 1 , wherein the phase component of the audio signal is modified based on a threshold related to a minimum audible angle (MAA).  
   
   
       6 . (canceled)  
   
   
       7 . The method of  claim 5 , wherein the threshold related to the minimum audible angle varies as a function of frequency.  
   
   
       8 . The method of  claim 1 , wherein the phase component of the audio signal is modified based on a threshold related to an interaural phase difference (IPD).  
   
   
       9 . The method of  claim 1 , wherein modifying at least a portion of the phase component of the audio signal to embed a second set of data is performed using at least one of one bit or multiple bits encoding per phase component.  
   
   
       10 . The method of  claim 1 , wherein the audio signal includes a first channel and a second channel, the first channel including a first phase component and the second channel including a second phase component.  
   
   
       11 . The method of  claim 10 , wherein modifying at least a portion of the phase component of the audio signal to embed the second set of data into the audio signal includes modifying at least a portion of at least one of the first phase component and the second phase component to embed the second set of data into at least one of the first channel and the second channel.  
   
   
       12 . The method of  claim 11 , wherein the at least one of the first phase component and the second phase component is modified if a portion of one of the first phase component and the second phase component is not different than a portion of the other one of the first phase component and the second phase component by more than a threshold based on psychoacoustic properties of human hearing.  
   
   
       13 . (canceled)  
   
   
       14 . (canceled)  
   
   
       15 . The method of  claim 11 , wherein at least one of the first phase component and the second phase component is determined using Fourier analysis.  
   
   
       16 . The method of  claim 15 , wherein the amount of the second set of data is dependent on the phase of uniform quantization levels of the at least one of the first phase component and the second phase component.  
   
   
       17 . The method of  claim 1 , wherein a frequency component of the audio signal having an interaural phase difference (IPD) below an audible threshold is set to zero for compression of the audio signal.  
   
   
       18 . A method for determining data embedded into an audio signal, the audio signal being based on a first set of data of an original audio signal and including a phase component, the method comprising: 
 determining a second set of data embedded into the audio signal based on the phase component of the audio signal,    wherein the audio signal differs with respect to the original audio signal in a manner that is at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data.    
   
   
       19 . The method of  claim 18 , wherein at least one of (i) the first set of data and (ii) the second set of data includes at least one of audio data, text data, video data, image data, and multimedia data.  
   
   
       20 . The method of  claim 18 , wherein the second set of data includes encrypted data.  
   
   
       21 . The method of  claim 18 , wherein the second set of data includes at least one of authentication data, content enhancement data, and distribution control data.  
   
   
       22 . The method of  claim 18 , wherein determining a second set of data embedded into the audio signal based on the phase component of the audio signal is performed using at least one of one bit or multiple bits decoding per phase component.  
   
   
       23 . The method of  claim 18 , wherein the audio signal includes a first channel and a second channel, the first channel including a first phase component and the second channel including a second phase component:  
   
   
       24 . The method of  claim 23 , wherein at least one of the first phase component and the second phase component is determined using Fourier analysis.  
   
   
       25 . (canceled)  
   
   
       26 . The method of  claim 25 , wherein a data bit of the second set of data embedded into the audio signal is determined to be a second logical value if a portion of one of the first phase component and the second phase component differs from a portion of the other of the first phase component and the second phase component by less than or equal to a second threshold related to an inter aural phase difference (IPD) but more than the first threshold related to an interaural phase difference (IPD).  
   
   
       27 . An apparatus for embedding data into an audio signal, the audio signal being based on a first set of data and including a phase component, the apparatus comprising: 
 a processor configured to modify at least a portion of the phase component of the audio signal to embed a second set of data into the audio signal,    wherein the second set of data embedded into the audio signal can be made at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data depending on the extent that the phase component of the audio signal is modified.    
   
   
       28 . The apparatus of  claim 27 , wherein at least one of (i) the first set of data and (ii) the second set of data includes at least one of audio data, text data, video data, image data, and multimedia data.  
   
   
       29 . The apparatus of  claim 27 , wherein the second set of data includes encrypted data.  
   
   
       30 . The apparatus of  claim 27 , wherein the second set of data includes at least one of authentication data, content enhancement data, and distribution control data.  
   
   
       31 . The apparatus of  claim 27 , wherein the processor is configured to modify the phase component of the audio signal based on a threshold related to a minimum audible angle (MAA).  
   
   
       32 . (canceled)  
   
   
       33 . The apparatus of  claim 31 , wherein the threshold related to the minimum audible angle varies as a function of frequency.  
   
   
       34 . The apparatus of  claim 27 , wherein the processor is configured to modify the phase component of the audio signal based on a threshold related to an interaural phase difference (IPD).  
   
   
       35 . The apparatus of  claim 27 , wherein the processor is configured to modify at least a portion of the phase component of the audio signal to embed a second set of data into the audio signal using at least one of one bit or multiple bits encoding per phase component.  
   
   
       36 . The apparatus of  claim 27 , wherein the audio signal includes a first channel and a second channel, the first channel including a first phase component and the second channel including a second phase component.  
   
   
       37 . The apparatus of  claim 36 , wherein modifying at least a portion of the phase component of the audio signal to embed the second set of data into the audio signal includes modifying at least a portion of at least one of the first phase component and the second phase component to embed the second set of data into at least one of the first channel and the second channel.  
   
   
       38 . The apparatus of  claim 37 , wherein the processor is configured to modify the at least one of the first phase component and the second phase component if a portion of one of the first phase component and the second phase component is not different than a portion of the other one of the first phase component and the second phase component by more than a threshold based on psychoacoustic properties of human hearing.  
   
   
       39 . (canceled)  
   
   
       40 . (canceled)  
   
   
       41 . The apparatus of  claim 36 , wherein the processor is configured to determine at least one of the first phase component and the second phase component using Fourier analysis.  
   
   
       42 . The apparatus of  claim 41 , wherein the amount of the second set of data is dependent on the phase of uniform quantization levels of the at least one of the first phase component and the second phase component.  
   
   
       43 . The apparatus of  claim 27 , wherein a frequency component of the audio signal having an interaural phase difference (IPD) below an audible threshold is set to zero for compression of the audio signal.  
   
   
       44 . An apparatus for determining data embedded into an audio signal, the audio signal being based on a first set of data of an original audio signal and including a phase component, the apparatus comprising: 
 a processor configured to determine a second set of data embedded into the audio signal based on the phase component of the audio signal,    wherein the audio signal differs with respect to the original audio signal in a manner that is at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data.    
   
   
       45 . The apparatus of  claim 44 , wherein at least one of (i) the first set of data and (ii) the second set of data includes at least one of audio data, text data, video data, image data, and multimedia data.  
   
   
       46 . The apparatus of  claim 44 , wherein the second set of data includes encrypted data.  
   
   
       47 . The apparatus of  claim 44 , wherein the second set of data includes at least one of authentication data, content enhancement data, and distribution control data.  
   
   
       48 . The apparatus of  claim 44 , wherein the processor is configured to determine a second set of data embedded into the audio signal based on the phase component of the audio signal using at least one of one bit or multiple bits decoding per phase component.  
   
   
       49 . The apparatus of  claim 44 , wherein the audio signal includes a first channel and a second channel, the first channel including a first phase component and the second channel including a second phase component.  
   
   
       50 . The apparatus of  claim 49 , wherein the processor is configured to determine at least one of the first phase component and the second phase component using Fourier analysis.  
   
   
       51 . (canceled)  
   
   
       52 . The apparatus of  claim 51 , wherein the processor is configured to determine a data bit of the second set of data embedded into the audio signal to be a second logical value if a portion of one of the first phase component and the second phase component differs from a portion of the other of the first phase component and the second phase component by less than or equal to a second threshold related to an interaural phase difference (IPD) but more than the first threshold related to an interaural phase difference (IPD).  
   
   
       53 . A machine-readable medium having encoded information, which when read and executed by a machine causes a method for embedding data into an audio signal, the audio signal being based on a first set of data and including a phase component, the method comprising: 
 modifying at least a portion of the phase component of the audio signal to embed a second set of data into the audio signal,    wherein the second set of data embedded into the audio signal can be made at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data depending on the extent that the phase component of the audio signal is modified.    
   
   
       54 . The machine-readable medium of  claim 53 , wherein at least one of (i) the first set of data and (ii) the second set of data includes at least one of audio data, text data, video data, image data, and multimedia data.  
   
   
       55 . The machine-readable medium of  claim 53 , wherein the second set of data includes encrypted data.  
   
   
       56 . The machine-readable medium of  claim 53 , wherein the second set of data includes at least one of authentication data, content enhancement data, and distribution control data.  
   
   
       57 . The machine-readable medium of  claim 53 , wherein the phase component of the audio signal is modified based on a threshold related to a minimum audible angle (MAA).  
   
   
       58 . (canceled)  
   
   
       59 . The machine-readable medium of  claim 57 , wherein the threshold related to the minimum audible angle varies as a function of frequency.  
   
   
       60 . The machine-readable medium of  claim 53 , wherein the phase component of the audio signal is modified based on a threshold related to an interaural phase difference (IPD).  
   
   
       61 . The machine-readable medium of  claim 53 , wherein modifying at least a portion of the phase component of the audio signal to embed a second set of data is performed using at least one of one bit or multiple bits encoding per phase component.  
   
   
       62 . The machine-readable medium of  claim 53 , wherein the audio signal includes a first channel and a second channel, the first channel including a first phase component and the second channel including a second phase component.  
   
   
       63 . The machine-readable medium of  claim 62 , wherein modifying at least a portion of the phase component of the audio signal to embed the second set of data into the audio signal includes modifying at least a portion of at least one of the first phase component and the second phase component to embed the second set of data into at least one of the first channel and the second channel.  
   
   
       64 . The machine-readable medium of  claim 63 , wherein the at least one of the first phase component and the second phase component is modified if a portion of one of the first phase component and the second phase component is not different than a portion of the other one of the first phase component and the second phase component by more than a threshold based on psychoacoustic properties of human hearing.  
   
   
       65 . (canceled)  
   
   
       66 . (canceled)  
   
   
       67 . The machine-readable medium of  claim 62 , wherein at least one of the first phase component and the second phase component is determined using Fourier analysis.  
   
   
       68 . The machine-readable medium of  claim 67 , wherein the amount of the second set of data is dependent on the phase of uniform quantization levels of the at least one of the first phase component and the second phase component.  
   
   
       69 . The machine-readable medium of  claim 53 , wherein a frequency component of the audio signal having an interaural phase difference (IPD) below an audible threshold is set to zero for compression of the audio signal.  
   
   
       70 . A machine-readable medium having encoded information, which when read and executed by a machine causes a method for determining data embedded into an audio signal, the audio signal being based on a first set of data of an original audio signal and including a phase component, the method comprising: 
 determining a second set of data embedded into the audio signal based on the phase component of the audio signal,    wherein the audio signal differs with respect to the original audio signal in a manner that is at least one of (i) substantially imperceptible and (ii) imperceptible to a listener of the first set of data.    
   
   
       71 . The machine-readable medium of  claim 70 , wherein at least one of (i) the first set of data and (ii) the second set of data includes at least one of audio data, text data, video data, image data, and multimedia data.  
   
   
       72 . The machine-readable medium of  claim 70 , wherein the second set of data includes encrypted data.  
   
   
       73 . The machine-readable medium of  claim 70 , wherein the second set of data includes at least one of authentication data, content enhancement data, and distribution control data.  
   
   
       74 . The machine-readable medium of  claim 70 , wherein determining a second set of data embedded into the audio signal based on the phase component of the audio signal is performed using at least one of one bit or multiple bits decoding per phase component.  
   
   
       75 . The machine-readable medium of  claim 70 , wherein the audio signal includes a first channel and a second channel, the first channel including a first phase component and the second channel including a second phase component.  
   
   
       76 . The machine-readable medium of  claim 75 , wherein at least one of the first phase component and the second phase component is determined using Fourier analysis.  
   
   
       77 . (canceled)  
   
   
       78 . The machine-readable medium of  claim 77 , wherein a data bit of the second set of data embedded into the audio signal is determined to be a second logical value if a portion of one of the first phase component and the second phase component differs from a portion of the other of the first phase component and the second phase component by less than or equal to a second threshold related to an interaural phase difference (IPD) but more than the first threshold related to an interaural phase difference (IPD).