Information processing for retrieving coded audiovisual data

Abstract

In order to efficiently retrieve AV data by using signal characteristics as retrieval conditions, in a first step, a comparison and determination section computes a correlation coefficient (degree of similarity) of a spectrum coefficient of coded audio data and a spectrum coefficient of a sample waveform, and extracts correlation coefficients such that the value of the computed spectrum coefficient is larger than a threshold value which is set in the first step, and assumes them to be retrieval results. In a second step, the comparison and determination section determines whether or not the retrieval result is satisfactory. When it is determined that the number of pieces of audio data retrieved in the first step is equal to or greater than the predetermined threshold value and the retrieval result is not satisfactory, the process proceeds to a third step. In the third step, the comparison and determination section determines whether or not the number of frequency bands of the sample waveform, which is the retrieval conditions, is less than its maximum value. When it is determined that the number of frequency bands is less than its maximum value, in a fourth step, the number of frequency bands of the waveform signal, which is the retrieval conditions, is incremented by 1, and the process returns to the first step.