Time-series active search for quick retrieval of audio and video

This paper proposes a search method that can quickly detect and locate known sound (video) in a long audio (video) stream. The method is based on active search. Active search reduces the number of candidate matches between reference and input signals by approximately 10 to 100 times compared to exhaustive search, while guaranteeing the same retrieval accuracy. We proposed a quick search method in Smith et al. (1998), and here we focus on improvement of the accuracy. Thus the feature used has been extended to the audio power spectrum and temporal division of the histogram windows has been introduced to incorporate time information. Tests carried out under practical circumstances clearly show the accuracy improvement. The proposed method is still so fast that it can correctly retrieve a 15-s commercial in a 6-h recording of TV broadcasting within 2 s, once the features are calculated.