Patent ID: 9424856
Filing Date: 2016-08-23
CPC Classification: G10L

Claim Text:
1. A method of filling residual sub-vectors that were not coded in a transform coded audio signal, which are referred to as non-coded residual sub-vectors, said method performed by a processing circuit configured as an audio decoder and comprising: compressing the residual sub-vectors that were coded in the transform coded audio signal, which are referred to as coded residual sub-vectors, to obtain compressed residual sub-vectors; rejecting those compressed residual sub-vectors that do not fulfill a pre-determined sparseness criterion, to obtain remaining compressed residual sub-vectors; concatenating the remaining compressed residual sub-vectors to obtain coefficients comprising a first virtual codebook; combining pairs of the coefficients of the first virtual codebook to obtain coefficients comprising a second virtual codebook; filling the non-coded residual sub-vectors to obtain corresponding filled residual sub-vectors, based on using coefficients from the first virtual codebook to fill the non-coded residual sub-vectors that correspond to frequency bands below a predetermined frequency and, using coefficients from the second virtual codebook to fill the non-coded residual sub-vectors that correspond to frequency bands above the predetermined frequency; and forming an audio signal using the coded residual sub-vectors and the filled residual sub-vectors.