Methods and apparatus for watermark outage detection

1. An apparatus comprising:

at least one memory;

instructions; and

processor circuitry to execute the instructions to at least:

evaluate at least one of an onset time or a duration of a detected watermark outage based on at least one model representative of expected watermark outages to determine whether the detected watermark outage corresponds to at least one of the expected watermark outages represented in the at least one model;

generate an alert in response to a determination that the detected watermark outage does not correspond to any of the expected watermark outages represented in the at least one model; and

suppress the alert in response to a determination that the detected watermark outage corresponds to a first one of the expected watermark outages represented in the at least one model.

2. The apparatus of claim 1 , wherein the at least one model includes at least one of a first model representative of the expected watermark outages or a second model representative of the expected watermark outages, the first model to represent expected sequences of the expected watermark outages, the second model to represent expected clusters of the expected watermark outages.

3. The apparatus of claim 1 , wherein the processor circuitry is to reset a watermark encoder in response to the determination that the detected watermark outage does not correspond to any of the expected watermark outages represented in the at least one model.

4. The apparatus of claim 2 , wherein the first model includes:

states representative of onset times of respective ones of the expected watermark outages represented in the first model; and

transitions between respective pairs of the states, respective ones of the transitions associated with corresponding probabilities of occurrence of pairs of previous watermark outages and subsequent watermark outages represented by the respective pairs of the states.

5. The apparatus of claim 2 , wherein to evaluate the at least one of the onset time or the duration of the detected watermark outage, the processor circuitry is to:

determine whether the onset of the detected watermark outage corresponds to any of the clusters included in the second model; and

in response to a determination that the onset of the detected watermark outage corresponds to a first one of the clusters, determine whether the duration of the detected watermark outage falls into the first one of the clusters.

6. The apparatus of claim 4 , wherein the states are representative of the onset times and durations of the respective ones of the expected watermark outages represented in the first model.

7. The apparatus of claim 4 , wherein the detected watermark outage is a second detected watermark outage, the onset time of the detected watermark outage is a second onset time of the second detected watermark outage, and to evaluate the second onset time of the second detected watermark outage, the processor circuitry is to determine whether the second onset time of the second detected watermark outage and a first onset time of a preceding first detected watermark outage correspond to a transition between a first state and a second state included in the first model, the first state representative of the first onset time and the second state representative of the second onset time.

8. At least one non-transitory computer readable medium comprising computer readable instructions that, when executed, cause at least one processor to at least:

evaluate at least one of an onset time or a duration of a detected watermark outage based on at least one model representative of expected watermark outages to determine whether the detected watermark outage corresponds to at least one of the expected watermark outages represented in the at least one model;

generate an alert in response to a determination that the detected watermark outage does not correspond to any of the expected watermark outages represented in the at least one model; and

suppress the alert in response to a determination that the detected watermark outage corresponds to a first one of the expected watermark outages represented in the at least one model.

9. The at least one non-transitory computer readable medium of claim 8 , wherein the at least one model includes at least one of a first model representative of the expected watermark outages or a second model representative of the expected watermark outages, the first model to represent expected sequences of the expected watermark outages, the second model to represent expected clusters of the expected watermark outages.

10. The at least one non-transitory computer readable medium of claim 8 , wherein the instructions are to cause the at least one processor to reset a watermark encoder in response to the determination that the detected watermark outage does not correspond to any of the expected watermark outages represented in the at least one model.

11. The at least one non-transitory computer readable medium of claim 9 , wherein the first model includes:

states representative of onset times of respective ones of the expected watermark outages represented in the first model; and

transitions between respective pairs of the states, respective ones of the transitions associated with corresponding probabilities of occurrence of pairs of previous watermark outages and subsequent watermark outages represented by the respective pairs of the states.

12. The at least one non-transitory computer readable medium of claim 9 , wherein to evaluate the at least one of the onset time or the duration of the detected watermark outage, the instructions are to cause the at least one processor to:

determine whether the onset of the detected watermark outage corresponds to any of the clusters included in the second model; and

in response to a determination that the onset of the detected watermark outage corresponds to a first one of the clusters, determine whether the duration of the detected watermark outage falls into the first one of the clusters.

13. The at least one non-transitory computer readable medium of claim 11 , wherein the states are representative of the onset times and durations of the respective ones of the expected watermark outages represented in the first model.

14. The at least one non-transitory computer readable medium of claim 11 , wherein the detected watermark outage is a second detected watermark outage, the onset time of the detected watermark outage is a second onset time of the second detected watermark outage, and to evaluate the second onset time of the second detected watermark outage, the instructions are to cause the at least one processor to determine whether the second onset time of the second detected watermark outage and a first onset time of a preceding first detected watermark outage correspond to a transition between a first state and a second state included in the first model, the first state representative of the first onset time and the second state representative of the second onset time.

15. An apparatus comprising:

at least one memory;

instructions; and

processor circuitry to execute the instructions to at least:

determine whether a first onset time of a first detected watermark outage included in watermark outage data and a second onset time of a preceding second detected watermark outage included in the watermark outage data correspond to at least one state transition included in a model representative of expected watermark outages; and

in response to a determination that the first onset time of the first detected watermark outage and the second onset time of the second detected watermark outage correspond to a first state transition between a first state and a second state included in the model, associate the first detected watermark outage with the first state and update one or more values associated with a corresponding one or more state transitions included in the model.

16. The apparatus of claim 15 , wherein the model includes:

a plurality of states representative of onset times of respective ones of the expected watermark outages represented in the model, the plurality of states including the first state and the second state, the first state associated with the first onset time, the second state associated with the second onset time; and

a plurality of state transitions between respective pairs of the plurality of states, respective ones of the transitions associated with corresponding probabilities of occurrence of pairs of previous watermark outages and subsequent watermark outages represented by the respective pairs of the states.

17. The apparatus of claim 15 , wherein the processor circuitry is to, in response to a determination that the first onset time of the first detected watermark outage and the second onset time of the second detected watermark outage do not correspond to any state transition included in the model:

add a new state representative of the first onset time of the first detected watermark outage to the model; and

add a new state transition to the model, the new state transition from an existing state representative of the second onset time to the new state representative of the first onset time.

18. The apparatus of claim 15 , wherein the processor circuitry is to:

evaluate a sliding time window that defines a first portion of the watermark outage data to be utilized to generate the model; and

update the model to exclude contributions from a second portion of the watermark outage data that is outside the sliding time window.

19. The apparatus of claim 15 , wherein the model is a first model, and the processor circuitry is to:

determine whether a third onset time for a third detected watermark outage in the watermark outage data corresponds to at least one cluster in a second model representative of expected watermark outages; and

in response to a determination that the third detected watermark outage is associated with a first cluster in the second model, determine whether a duration of the third watermark outage falls into the first cluster.

20. The apparatus of claim 19 , wherein the processor circuitry is to:

associate the third detected watermark outage with the first cluster in response to a determination that the duration of the third detected watermark outage falls into the first cluster; and

generate a new cluster to include in the second model in response to a determination that the duration of the third detected watermark outage does not falls into the first cluster, the new cluster corresponding to the third onset time and the duration of the third detected watermark outage.