Patent ID: 9117440
Filing Date: 2015-08-25
Classification: G10L

Abstract:
1. A method for detecting frequency extension coding in the coding history of an audio signal, the method comprising providing a plurality of subband signals in a corresponding plurality of subbands comprising low and high frequency subbands, the plurality of subband signals generated using a filter bank comprising a plurality of filters; wherein the plurality of subband signals corresponds to a time/frequency domain representation of the audio signal; determining a degree of relationship between subband signals in the low frequency subbands and subband signals in the high frequency subbands; wherein the degree of relationship is determined based on the plurality of subband signals; wherein determining the degree of relationship comprises determining a set of cross-correlation, wherein the set of cross-correlation values comprises a subset of elements of a K x K similarity matrix, wherein the K x K similarity matrix comprises cross-correlation values corresponding to all pairs of subband signals from the plurality of subband signals; wherein determining a cross-correlation value comprises determining an average over time of products of corresponding samples of a first and a second subband signal at zero time lag; and determining frequency extension coding history if the degree of relationship is greater than a relationship threshold.