Methods and apparatus to inspect characteristics of multichannel audio
View Patent ↗Methods, apparatus, systems and articles of manufacture are disclosed for audio watermarking and, more particularly, methods and apparatus to inspect characteristics of multichannel audio. Example methods disclosed herein are further to obtain an audio subchannel of the multichannel audio signal, detect an embedded watermark in the audio subchannel of the multichannel audio signal, determine a characteristic of the audio subchannel of the multichannel audio signal based on the embedded watermark, and in response to determining an issue with the characteristic of the audio subchannel of the multichannel audio signal, distribute an alert.
1. An apparatus to determine a mapping characteristic of a multichannel audio signal, the apparatus comprising:
an audio demultiplexer to obtain an audio subchannel of the audio signal;
a watermark detector to detect an embedded watermark in the audio subchannel of the multichannel audio signal;
a channel characteristic inspector to determine the mapping characteristic of the audio subchannel of the multichannel audio signal based on the embedded watermark, the channel characteristic inspector further to:
determine a quantity of embedded watermarks in the audio subchannel; and
identify an improper mapping characteristic based on the quantity of embedded watermarks in the audio subchannel; and
a result alerter to distribute an alert when the improper mapping characteristic of the audio subchannel of the multichannel audio signal is identified.
2. The apparatus of claim 1 , wherein the channel characteristic inspector further includes a channel mapping inspector to determine an availability of an audio channel identifier watermark in the audio subchannel of the multichannel audio signal.
3. The apparatus as defined in claim 2 , wherein the channel mapping inspector is further to, when the audio channel identifier watermark is available:
identify the improper mapping characteristic when the audio subchannel of the multichannel audio signal does not contain a proper audio channel identifier watermark; and
determine the mapping characteristic is correct, when the audio subchannel of the multichannel audio signal contains the proper audio channel identifier watermark.
4. The apparatus of claim 2 , wherein when the audio channel identifier watermark is unavailable:
the audio demultiplexer is further to:
determine the audio subchannel is a first audio subchannel of the multichannel audio signal;
obtain a second audio subchannel of the multichannel audio signal; and
obtain a third audio subchannel of the multichannel audio signal;
the watermark detector is further to detect an embedded watermark in each of the second and third audio subchannels of the multichannel audio signal;
the channel characteristic inspector further includes a watermark manager to determine a quantity of embedded watermarks in each of the first, second and third audio subchannels; and
the channel mapping inspector is further to:
identify a possible improper mapping characteristic when the quantity of embedded watermarks in at least one of the first and second audio subchannels is dissimilar;
identify the improper mapping characteristic when the quantity of embedded watermarks in the third audio subchannel is significant compared to the quantity of embedded watermarks in the first audio subchannel; and
determine the mapping characteristic is correct when the quantity of embedded watermarks in the third audio subchannel is insignificant compared to the quantity of embedded watermarks in the first audio subchannel.
5. A method of inspecting a mapping characteristic of a multichannel audio signal, the method comprising:
obtaining an audio subchannel of the multichannel audio signal;
detecting an embedded watermark in the audio subchannel of the multichannel audio signal;
determining the mapping characteristic of the audio subchannel of the multichannel audio signal based on the embedded watermark, the determining further including:
determining a quantity of embedded watermarks in the audio subchannel; and
identifying an improper mapping characteristic based on the quantity of embedded watermarks in the audio subchannel; and
in response to identifying the improper mapping characteristic of the audio subchannel of the multichannel audio signal, distributing an alert.
6. The method of claim 5 , wherein the mapping characteristic of the audio subchannel of the multichannel audio signal can further be stored in a facility in response to at least one of a presence of an issue with the characteristic of the audio subchannel of the multichannel audio signal or an absence of an issue with the characteristic of the audio subchannel of the multichannel audio signal.
7. The method of claim 5 , further including determining an availability of an audio channel identifier watermark in the audio subchannel of the multichannel audio signal.
8. The method of claim 7 , wherein determining the channel mapping further includes, in response to the availability of the audio channel identifier watermark embedded in the audio subchannel of the multichannel audio signal:
identifying, in response to the audio subchannel of the multichannel audio signal not containing a proper audio channel identifier watermark, the improper mapping characteristic; and
determining, in response to the audio subchannel of the multichannel audio signal containing the proper audio channel identifier watermark, the mapping characteristic is correct.
9. The method of claim 7 , wherein determining the channel mapping further includes, in response to an unavailability of the audio channel identifier watermark embedded in the audio subchannel of the multichannel audio signal:
the audio subchannel is a first audio subchannel of the multichannel audio signal;
obtaining a second audio subchannel of the multichannel audio signal;
obtaining a third audio subchannel of the multichannel audio signal;
detecting an embedded watermark in each of the second and third audio subchannels of the multichannel audio signal;
determining a quantity of embedded watermarks in each of the first, second and third audio subchannels;
identifying, in response to the quantity of embedded watermarks in at least one of the first and second audio subchannels being dissimilar, a possible improper mapping characteristic;
identifying, in response to the quantity of embedded watermarks in the third audio subchannel being significant when compared to the quantity of embedded watermarks in the first audio subchannel, the improper mapping characteristic; and
determining, in response to the quantity of embedded watermarks in the third audio subchannel being insignificant compared to the quantity of embedded watermarks in the first audio subchannel, the mapping characteristic is correct.
10. A non-transitory machine readable storage medium comprising machine readable instructions which, when executed, cause a machine to at least:
obtain, with a processor, an audio subchannel of a multichannel audio signal;
detect, with the processor, an embedded watermark in the audio subchannel of the multichannel audio signal;
determine, with the processor, a characteristic of the audio subchannel of the multichannel audio signal based on the embedded watermark, the determining further including:
determining a quantity of embedded watermarks in the audio subchannel; and
identifying an improper mapping characteristic based on the quantity of embedded watermarks in the audio subchannel; and
distribute, with the processor, an alert when the improper mapping characteristic of the audio subchannel of the multichannel audio signal is identified.
11. The storage medium of claim 10 , wherein the mapping characteristic of the audio subchannel of the multichannel audio signal can further be stored in a facility in response to at least one of a presence of an issue with the characteristic of the audio subchannel of the multichannel audio signal or an absence of an issue with the characteristic of the audio subchannel of the multichannel audio signal.
12. The storage medium of claim 10 , wherein the instructions, when executed, cause the machine to determine an availability of an audio channel identifier watermark in the audio subchannel of the multichannel audio signal.
13. The storage medium of claim 12 , wherein the instructions, when executed, further cause the machine to, when the audio channel identifier watermark is available:
identify the improper mapping characteristic when the audio subchannel of the multichannel audio signal does not contain a proper audio channel identifier watermark; and
determine the mapping characteristic is correct, when the audio subchannel of the multichannel audio signal contains the proper audio channel identifier watermark.
14. The storage medium of claim 12 , wherein the instructions, when executed, cause the machine to, when the audio channel identifier watermark is unavailable:
determine the audio subchannel is a first audio subchannel of the multichannel audio signal;
obtain a second audio subchannel of the multichannel audio signal;
obtain a third audio subchannel of the multichannel audio signal;
detect an embedded watermark in each of the second and third audio subchannels of the multichannel audio signal;
determine a quantity of embedded watermarks in each of the second and third audio subchannels;
identify a possible improper mapping characteristic when the quantity of embedded watermarks in at least one of the first and second audio subchannels is dissimilar;
identify the improper mapping characteristic when the quantity of embedded watermarks in the third audio subchannel is significant when compared to the quantity of embedded watermarks in the first audio subchannel; and
determine the mapping characteristic is correct when the quantity of embedded watermarks in the third audio subchannel is insignificant compared to the quantity of embedded watermarks in the first audio subchannel.
15. An apparatus to determine a timing characteristic of a multichannel audio signal, the apparatus comprising:
an audio demultiplexer to obtain first and second audio subchannels of the multichannel audio signal;
a watermark detector to detect a first embedded watermark associated with the first audio subchannel and a second embedded watermark associated with the second audio subchannel;
a channel characteristic inspector to determine the timing characteristic of the multichannel audio signal, the channel characteristic inspector further to:
extract a first timestamp from the first embedded watermark and a second timestamp from the second embedded watermark; and
identify an improper timing characteristic based on a comparison of a first time associated with the first timestamp to a second time associated with the second timestamp; and
a result alerter to distribute an alert when the improper timing characteristic of the audio subchannel of the multichannel audio signal is identified.
16. The apparatus of claim 15 , wherein
the channel characteristic inspector further includes:
a watermark timestamp extractor to extract the first timestamp from the first embedded watermark of the first audio subchannel and the second timestamp from the second embedded watermark of the second audio subchannel of the multichannel audio signal; and
a channel timing inspector to:
identify the improper timing characteristic, when a time discrepancy exists for the first and second timestamps extracted from the first and second embedded watermarks in the first and second audio subchannels; and
determine the timing characteristic is correct, when the first and second timestamps extracted from the first and second embedded watermarks in the first and second audio subchannels contain synchronized timestamps.
17. A method of inspecting a timing characteristic of a multichannel audio signal, the method comprising:
obtaining first and second audio subchannels of the multichannel audio signal;
detecting a first embedded watermark associated with the first audio subchannel and a second embedded watermark associated with the second audio subchannel;
determining the timing characteristic of the multichannel audio signal, the determining further including:
extracting a first timestamp from the first embedded watermark and a second timestamp from the second embedded watermark; and
identifying an improper timing characteristic based on a comparison of a first time associated with the first timestamp to a second time associated with the second timestamp; and
in response to identifying the improper timing characteristic of the audio subchannel of the multichannel audio signal, distributing an alert.
18. The method of claim 17 , further including
identifying, using the first and second timestamps extracted from the first and second embedded watermarks in the first and second audio subchannels, in response to a time discrepancy existing, the improper timing characteristic; and
determining, using the first and second timestamps extracted from the first and second embedded watermarks in the first and second audio subchannels, in response to the first and second embedded watermarks in the first and second audio subchannels containing synchronized timestamps, the timing characteristic is correct.
19. A non-transitory machine readable storage medium comprising machine readable instructions which, when executed, cause a machine to at least:
obtain, with a processor, first and second audio subchannels of a multichannel audio signal;
detect, with the processor, a first embedded watermark associated with the first audio subchannel and a second embedded watermark associated with the second audio subchannel;
determine, with the processor, a timing characteristic of the multichannel audio signal, the determining further including:
extracting a first timestamp from the first embedded watermark and a second timestamp from the second embedded watermark; and
identifying an improper timing characteristic based on a comparison of a first time associated with the first timestamp to a second time associated with the second timestamp; and
distribute, with the processor, an alert when the timing characteristic of the audio subchannel of the multichannel audio signal is identified.
20. The storage medium of claim 19 , wherein the instructions, when executed, further cause the machine to:
identify the improper timing characteristic, when a time discrepancy exists for the first and second timestamps extracted from the first and second embedded watermarks in the first and second audio subchannels; and
determine the timing characteristic is correct, when the first and second timestamps extracted from the first and second embedded watermarks in the first and second audio subchannels contain synchronized timestamps.