Methods and apparatus to identify and credit media using ratios of media characteristics

An apparatus comprising:

• at least one processor;
• and
• a non-transitory computer readable storage medium having stored therein computer readable instructions that, upon execution by the at least one processor, cause the apparatus to implement:
• a media characterizer to identify media characteristics of a monitored media signal;
• a delta calculator to:
• calculate respective time intervals between corresponding adjacent ones of the media characteristics;
• and
• calculate ratios of the time intervals;
• and
• a signature generator to generate a ratio signature representative of the monitored media signal, the ratio signature generated based on the ratios.

A non-transitory machine readable storage medium having stored therein instructions to, upon execution of the instructions by at least one processor, cause performance of at least:

• identifying media characteristics of a monitored media signal;
• calculating respective time intervals between corresponding adjacent ones of the media characteristics;
• calculating ratios of the time intervals;
• and
• generating a ratio signature representative of the monitored media signal, the ratio signature generated based on the ratios.