Monitoring Presentation Timestamps

Abstract

Techniques to monitor presentation timestamps for content are described, which may be used to render content at a client. In an implementation, content is received having timestamps that define expected timing for output of the content at a client. The timestamps may then be monitored and compared to a client clock to determine if the content rendered matches the content expected to be rendered. When a discrepancy is detected, one or more corrective actions may be undertaken to restore output of the content to the timing defined by the timestamps.

1 . A method comprising:
 receiving packetized television content at a client device over an IP network from a network operator, the television content having timestamps encoded in the television content by the network operator to define timing for output of the television content at the client device;   initializing a client clock that is local to the client device to correspond to the timing defined by the timestamps;   outputting the television content at the client device;   monitoring the timestamps of the output television content to detect a deviation relative to the client clock; and   when a deviation is detected relative to the client clock, initiating one or more corrective actions to synchronize the output of the television content to the timing defined by the timestamps.   
     
     
         2 . A method as described in  claim 1 , wherein the monitoring comprises monitoring a difference established between the initialized client clock and the timing defined by the timestamps when output of the television content is initiated. 
     
     
         3 . A method as described in  claim 2 , wherein a tolerance value is defined for the difference such that said deviation is detected and the one or more corrective actions are initiated when the monitoring determines that the difference exceeds the tolerance value. 
     
     
         4 . A method as described in  claim 1 , wherein the corrective actions comprise resolving a hang up due to a data impairment by one or more of resetting the client device or resetting a renderer of the client device that is configured to output the television content. 
     
     
         5 . A method as described in  claim 1 , wherein the one or more corrective actions comprise skipping some portions of the content to restore output of the content to expected timing defined by the timestamps. 
     
     
         6 . A method as described in  claim 5 , wherein the skipping comprises obtaining and outputting a portion of the television content having a timestamp that matches an expected timestamp value to restore output of the television content to correspond with the timing defined by the timestamps. 
     
     
         7 . A method as described in  claim 1 , wherein the client device comprises a mobile client device. 
     
     
         8 . A method as described in  claim 1 , wherein the client device comprises a set-top box. 
     
     
         9 . A method as described in  claim 1 , wherein the one or more corrective actions comprise outputting a prompt to a viewer to select one or more corrective actions that are available. 
     
     
         10 . A method as described in  claim 1 , wherein the timestamps encoded in the television content comprises multiple different sets of timestamps that are associated with multiple different streams that make-up the content. 
     
     
         11 . A client device comprising:
 one or more processors; and   one or more computer-readable storage media storing computer-executable instructions executable via the one or more processors to perform acts including:
 receiving packetized video content over an IP network from a network operator, the television content having timestamps encoded in the video content by the network operator to define timing for output of the video content at the client device; 
 initializing a client clock that is local to the client device to correspond to the timing defined by the timestamps; 
 monitoring the timestamps during output of the video content to detect a deviation relative to the client clock; and 
 when a deviation is detected relative to the client clock, initiating one or more corrective actions to synchronize the output of the video content to the timing defined by the timestamps. 
   
     
     
         12 . A client device as described in  claim 11 , further comprising obtaining and outputting a portion of the video content having a timestamp that matches an expected timestamp value to restore output of the video content to correspond with the timing defined by the timestamps when the deviation is detected. 
     
     
         13 . A client device as described in  claim 11 , wherein monitoring comprises determining when a difference between the client clock and a presentation clock defined by the timestamps exceeds a configurable tolerance value established to set an acceptable amount for the difference that when exceeded triggers the corrective actions. 
     
     
         14 . A client device as described in  claim 11 , wherein the corrective actions comprise resolving a hang up due to a data impairment by one or more of resetting the client device or resetting a renderer of the client device that is configured to output the video content. 
     
     
         15 . A client device as described in  claim 11 , wherein initiating the one or more corrective actions comprises performing the one or more corrective actions automatically and without user intervention until output of the video content is restored to expected timing defined by the timestamps. 
     
     
         16 . One or more computer-readable media comprising computer-executable instructions that, when executed by a client, direct the client to perform operations including:
 receiving packetized content over a IP network from a network operator having associated timestamps that define a presentation clock for ordered output of the content;   when a portion of the content is rendered, comparing an associated said timestamp of the portion to a clock local to the client to verify that the rendering of the content is according to the presentation clock defined by the timestamps; and   when the comparison indicates that the rendering of the content deviates from the presentation clock, restoring the rendering of the content to accord with the presentation clock.   
     
     
         17 . One or more computer-readable media as described in  claim 16 , wherein the content is a television program. 
     
     
         18 . One or more computer-readable media as described in  claim 16 , wherein the timestamps are associated with the portions of the content by an encoder of the network operator. 
     
     
         19 . One or more computer-readable media as described in  claim 16 , wherein the network operator associates separate sets of timestamps derived from a common time-base with an audio stream and a video stream corresponding to the packetized content to enable separate control of the audio stream and the video stream by the client. 
     
     
         20 . One or more computer-readable media as described in  claim 16 , wherein restoring the rendering of the content further comprises instructing a renderer of the client to skip at least some portions of the content responsive to detection of a data impairment to restore output of the content to expected timing defined by the timestamps.