Method and system for detecting and responding to changing of media channel

1. A method of detecting and responding to a change of channels at a media presentation device, the method comprising:

while the media presentation device is presenting media content that was determined to be of a first channel, detecting a threshold mismatch between (i) a query fingerprint stream representing the media content being presented by the media presentation device and (ii) a reference fingerprint stream representing media content of the first channel, wherein the media content being presented by the media presentation device was determined to be of the first channel by comparing the query fingerprint stream with the reference fingerprint stream using a first fingerprint comparison rate and, based on the comparing, detecting a match between the query fingerprint stream and the reference fingerprint stream, wherein detecting the threshold mismatch is done by comparing the query fingerprint stream with the reference fingerprint stream using a second fingerprint comparison rate greater than the first fingerprint comparison rate, and wherein the threshold mismatch indicates a likelihood that the media presentation device has transitioned from presenting the first channel to presenting a second channel;

responsive to detecting the threshold mismatch, changing an overlay on the presented media content, wherein changing the overlay involves removing superimposed content associated with the first channel.

2. The method of claim 1 , wherein the superimposed content comprises an identification of the first channel.

3. The method of claim 1 , further comprising:

responsive to detecting the threshold mismatch, identifying the second channel,

wherein changing the overlay is further responsive to the identifying of the second channel and involves adding superimposed content associated with the identified second channel.

4. The method of claim 3 , wherein identifying the second channel comprises comparing the query fingerprint stream with reference fingerprint streams respectively representing a plurality of channels, and determining based on the comparing that the query fingerprint stream matches a reference fingerprint stream representing the second channel.

5. The of claim 1 , wherein the media content comprises video content, and wherein the overlay comprises a graphical overlay.

6. The method of claim 1 , carried out at least in part by the media presentation device.

7. A method for detecting and responding to a change of channels, the method comprising:

receiving into a computing system a plurality of query fingerprints representing media content rendered over time by a media presentation device, wherein, based on at least a portion of the received query fingerprints, the rendered media content has been identified as being a first channel of media content;

comparing one or more of the received query fingerprints to a corresponding one or more reference fingerprints representing the first channel of media content, wherein identifying the rendered media content as being the first channel of media content is done using a first fingerprint comparison rate, and wherein comparing the one or more of the received query fingerprints to a corresponding one or more reference fingerprints representing the first channel of media content is done using a second fingerprint comparison rate greater than the first fingerprint comparison rate;

based on the comparing, determining a likelihood that the media content being rendered by the media presentation device is no longer the first channel of media content; and

responsive to the determined likelihood that the media content being rendered by the media presentation device is no longer the first channel of media content, discontinuing a channel-specific action with respect to the rendering of the media content by the media presentation device.

8. The method of claim 7 ,

wherein the channel-specific action is based on the media content having been identified as being the first channel of media content and comprises superimposing first-channel-specific content on the media content being rendered by the media presentation device, and

wherein discontinuing the channel-specific action with respect to the rendering of the media content by the media presentation device comprises discontinuing the superimposing of the first-channel-specific content on the media content being rendered by the media presentation device.

9. The method of claim 8 , wherein the first-channel-specific content comprises an identification of the first channel.

10. The method of claim 9 , wherein the media content comprises video content, and wherein the first-channel-specific content comprises a graphical representation of the identification of the first channel.

11. The method of claim 7 , further comprising:

responsive to the determined likelihood that the media content being rendered by the media presentation device is no longer the first channel of media content, engaging in a process to identify the media content being rendered by the media presentation device as being a second channel of media content.

12. The method of claim 7 ,

wherein the channel-specific action is based on the media content having been identified as being the first channel of media content and comprises recording channel-ratings data based on presentation of the first channel by the media presentation device, and

wherein discontinuing the channel-specific action with respect to the rendering of the media content by the media presentation device comprises at least one operation selected from the group consisting of (i) discontinuing the recording of channel-ratings data based on presentation of the first channel by the media presentation device and (ii) recording channel-ratings data indicating discontinuation of presentation of the first channel by the media presentation device.

13. The method of claim 7 ,

wherein comparing the one or more received query fingerprints to the corresponding one or more reference fingerprints comprises comparing a particular one of the query fingerprints with a corresponding particular one of the reference fingerprints, and

wherein determining based on the comparing the likelihood that the media content being rendered by the media presentation device is no longer the first channel of media content comprises determining based on the comparing that the particular query fingerprint does not match the particular reference fingerprint.

14. The method of claim 7 ,

wherein comparing the one or more received query fingerprints to the corresponding one or more reference fingerprints comprises comparing t of the query fingerprints with a corresponding t of the reference fingerprints, wherein t>1, and

wherein comparing the t query fingerprints with the corresponding t reference fingerprints and determining based on the comparing the likelihood that the media content being rendered by the media presentation device is no longer the first channel of media content comprises (a) computing distances between the t query fingerprints and the t reference fingerprints, (b) summing the computed distances to establish a sum, and (c) using a sigmoid function to translate the established sum to a probability value representing the likelihood.

15. The method of claim 7 ,

wherein comparing the one or more of the received query fingerprints to the corresponding one or more reference fingerprints representing the first channel of media content is done with respect to a most recent one or more received query fingerprints.

16. The method of claim 7 , carried out at least in part by the media presentation device.

17. A system comprising:

a network communication interface;

a processing unit;

non-transitory data storage; and

program instructions stored in the non-transitory data storage and executable by the processing unit to carry out operations including:

receiving from a media presentation device, via the network communication interface, a query fingerprint stream representing media content being presented by the media presentation device, wherein the query fingerprint stream has been determined to represent a first channel, wherein determining that the query fingerprint stream represents the first channel is done using a first fingerprint comparison rate;

detecting a threshold mismatch between the received query fingerprint stream and a reference fingerprint stream representing the first channel, wherein detecting the threshold mismatch is done using a second fingerprint comparison rate greater than the first fingerprint comparison rate, and wherein the threshold mismatch indicates a likelihood that the media presentation device has transitioned from presenting the first channel to presenting a second channel, and

responsive to detecting the threshold mismatch, changing an overlay on the presented media content, wherein changing the overlay involves removing superimposed content associated with the first channel.

18. The system of claim 17 , wherein changing the overlay on the presented media content further involves adding superimposed content associated with the second channel.

19. The system of claim 17 , wherein the superimposed content comprises an identification of the first channel.

20. The system of claim 17 , wherein the media content comprises video content, and wherein the overlay comprises a graphical overlay.