System and method to detect garbled closed captioning

摘要

A garbled closed captioning detector analyzes closed captioning data at predetermined intervals to determine whether a metric derived from the closed-captioning data exceeds a threshold. If the metric exceeds the predetermined threshold, the closed captioning data is presumed to be garbled. For example, the metric may be the percentage of words in the closed captioning data having a desired word length observed in a particular interval compared to all words in the closed captioning data observed in the interval. If the percentage of words having a desired word length exceeds a predetermined threshold, the closed captioning data is presumed to be garbled.

主权项

1. A system to detect garbled closed captioning data, comprising:
a receiver to receive an encoded video data stream containing closed captioning data; a decoder to decode the encoded video data stream, and to reorder frames in the encoded video stream into display order; a closed captioning data detector to detect closed captioning data in the decoded, reordered video data stream; a data extractor to extract individual data elements from the detected closed captioning data; a data counter to count a total number of data elements in the closed captioning data as a total data element count, and to count a total number of data elements in the closed captioning data having a particular characteristic as a total data element characteristic count; a memory in which to store the total data element count and the data element characteristic count in the memory; a garbled closed captioning data detector to determine a metric as a function of the total data element count and the total data element characteristic count; and an alert generator that generates an alert in accordance with the determined metric.