Use of steganographically-encoded time information as basis to establish a time offset, to facilitate taking content-related action

A media client comprising:

• a content input interface;
• a content presentation 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 an ongoing channel of content that includes, at a time point in the channel of content, a watermark steganographically encoding a timestamp of the time point in the channel of content,
• extracting the timestamp from the watermark,
• computing a time offset based on a comparison of the extracted timestamp with client-time of the time point in the channel of content according to a clock of the media client, and
• using the computed time offset as a basis to determine when the media client is to carry out a content-related action.

Non-transitory data storage having stored program instructions executable by at least one processor to cause a media client to carry out operations comprising:

• receiving an ongoing channel of content that includes, at a time point in the channel of content, a watermark steganographically encoding a timestamp of the time point in the channel of content;
• extracting the timestamp from the watermark;
• computing a time offset based on a comparison of the extracted timestamp with client-time of the time point in the channel of content according to a clock of the media client;
• and
• using the computed time offset as a basis to determine when the media client is to carry out a content-related action.