Methods and apparatus to extend a timestamp range supported by a watermark

A watermark encoding apparatus comprising:

• means for determining which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark;
• means for swapping at least two symbols of the watermark when the timestamp is to represent a second one of the timestamp cycles, the means for swapping not to swap the at least two symbols of the watermark when the timestamp is to represent a first one of the timestamp cycles, the watermark including a first set of symbols representing data and a second set of symbols representing the timestamp, the first set of symbols including a first subset of symbols and a second subset of symbols, respective ones of the second subset of symbols to be determined from corresponding ones of the first subset of symbols based on another symbol not included in the first and second subsets of symbols, and the at least two symbols to be swapped are included in one of the first subset of symbols or the second subset of symbols, but not both of the first and second subsets of symbols;
• and
• means for embedding the watermark in a first piece of media.

A watermark decoding apparatus:

• at least one processor;
• computer readable instructions;
• and
• at least one processor to execute the instructions to:
• determine whether a first sequence of symbols of a decoded watermark obtained from a first piece of media is valid;
• swap at least two symbols of the decoded watermark to determine a second sequence of symbols when the first sequence of symbols is not valid;
• when the first sequence of symbols is valid, associate the decoded watermark with a first one of a plurality of timestamp cycles;
• and
• when the first sequence of symbols is not valid, associate the decoded watermark with a second one of the plurality of timestamp cycles when the second sequence of symbols is determined to be valid.

A watermark decoding apparatus comprising:

• means for determining whether a first sequence of symbols of a decoded watermark obtained from a first piece of media is valid;
• means for swapping at least two symbols of the decoded watermark to determine a second sequence of symbols when the first sequence of symbols is not valid;
• and
• means for associating the decoded watermark with one of a plurality of timestamp cycles, the means for associating to:
• associate the decoded watermark with a first one of the plurality of timestamp cycles when the first sequence of symbols is valid;
• and
• when the first sequence of symbols is not valid, associate the decoded watermark with a second one of the plurality of timestamp cycles when the second sequence of symbols is determined to be valid.