Content-modification system with jitter effect mitigation feature

A content-presentation device of a content-modification system that includes a content-distribution system, the content-presentation device comprising:

• one or more processors;
• and
• a non-transitory computer-readable storage medium, having stored thereon program instructions that, upon execution by the one or more processors, cause the content-presentation device to carry out operations including:
• making a first determination of an upcoming content-modification opportunity in content data received by the content-presentation device on an identified channel from the content-distribution system, wherein identification of the channel is based on a match between first reference fingerprint data representing a first transmitted portion of content data transmitted by the content-distribution system and first query fingerprint data representing at least a portion of the received content data, wherein the received content data comprises a sequence of content frames received at a source frame rate, and wherein the first query fingerprint data comprise a sequence of first query fingerprints that are generated by the content-presentation device from a first sub-sequence of content frames by sampling a first received portion of the sequence of content frames at a first frame sampling rate that is less than the source frame rate;
• receiving second reference fingerprint data representing a second transmitted portion of the content data transmitted by the content-distribution system, the second reference fingerprint data comprising a sequence of reference fingerprints received at the source frame rate, wherein the second transmitted portion follows the first transmitted portion;
• in response to receiving the second reference fingerprint data:
• (i) switching from the first frame sampling rate to a second, higher frame sampling rate, wherein the second frame sampling rate is no greater than the source frame rate, (ii) obtaining a second sub-sequence of content frames by sampling a second received portion of the received sequence of content frames at the second frame sampling rate, wherein the second received portion follows the first received portion, (iii) generating second query fingerprint data from the second sub-sequence of content frames, the second query fingerprint data comprising a sequence of second query fingerprints corresponding to the second sub-sequence of content frames, and (iv) making a second determination of whether or not the second query fingerprint data matches the received second reference fingerprint data to at least one matching threshold value by determining if a sliding window correlation of the sequence of second query fingerprints computed across the sequence of reference fingerprints produces at least one maximum value at least as great as the at least one matching threshold value;
• and
• in response to switching from the first frame sampling rate to the second, higher frame sampling rate, and prior to making the second determination, reducing the at least one matching threshold value to increase a tolerance to mis-matching of the second query fingerprint data to the second reference fingerprint data when the second sub-sequence of content frames is subject to frame jitter.

A non-transitory computer-readable storage medium, having stored thereon program instructions that, upon execution by one or more processors of a content-presentation device of a content-modification system that includes a content-distribution system, cause the content-presentation device to carry out operations including:

• making a first determination of an upcoming content-modification opportunity in content data received by the content-presentation device on an identified channel from the content-distribution system, wherein identification of the channel is based on a match between first reference fingerprint data representing a first transmitted portion of the content data transmitted by the content-distribution system and first query fingerprint data representing at least a portion of the received content data, wherein the received content data comprises a sequence of content frames received at a source frame rate, and wherein the first query fingerprint data comprise a sequence of first query fingerprints that are generated by the content-presentation device from a first sub-sequence of content frames by sampling a first received portion of the sequence of content frames at a first frame sampling rate that is less than the source frame rate;
• receiving second reference fingerprint data representing a second transmitted portion of the content data transmitted by the content-distribution system, the second reference fingerprint data comprising a sequence of reference fingerprints received at the source frame rate, wherein the second transmitted portion follows the first transmitted portion;
• in response to receiving the second reference fingerprint data:
• (i) switching from the first frame sampling rate to a second, higher frame sampling rate, wherein the second frame sampling rate is no greater than the source frame rate, (ii) obtaining a second sub-sequence of content frames by sampling a second received portion of the received sequence of content frames at the second frame sampling rate, wherein the second received portion follows the first received portion, (iii) generating second query fingerprint data from the second sub-sequence of content frames, the second query fingerprint data comprising a sequence of second query fingerprints corresponding to the second sub-sequence of content frames, and (iv) making a second determination of whether or not the second query fingerprint data matches the received second reference fingerprint data to at least one matching threshold value by determining if a sliding window correlation of the sequence of second query fingerprints computed across the sequence of reference fingerprints produces at least one maximum value at least as great as the at least one matching threshold value;
• and
• in response to switching from the first frame sampling rate to the second, higher frame sampling rate, and prior to making the second determination, reducing the at least one matching threshold value to increase a tolerance to mis-matching of the second query fingerprint data to the second reference fingerprint data when the second sub-sequence of content frames is subject to frame jitter.