Patent ID: 8694325
Filing Date: 2014-04-08
Classification: G10L,H03M

Abstract:
1. A hierarchical audio coding method, comprising following steps: dividing frequency domain coefficients of an audio signal for which Modified Discrete Cosine Transform (MDCT) has been performed into core layer frequency domain coefficients and extended layer frequency domain coefficients, and dividing the core layer frequency domain coefficients and extended layer frequency domain coefficients into a plurality of coding sub-bands, and quantizing and coding amplitude envelope values of the coding sub-bands; allocating bits to each coding sub-band of a core layer according to the amplitude envelope value of each coding sub-band of the core layer, and then quantizing and coding the core layer frequency domain coefficients to obtain coded bits of the core layer frequency domain coefficients; calculating an amplitude envelope value of each coding sub-band of a core layer residual signal according to the amplitude envelope value and a bit allocation number of each coding sub-band of the core layer; allocating bits to each coding sub-band of an extended layer according to an extended layer coding signal composed of the core layer residual signal and the extended layer frequency domain coefficients and the amplitude envelope value of each coding sub-band composed of the extended layer coding signal, and then quantizing and coding the extended layer coding signal to obtain coded bits of the extended layer coding signal; and multiplexing and packing amplitude value envelope coded bits of each coding sub-band composed of the core layer frequency domain coefficients and the extended layer frequency domain coefficients, coded bits of the core layer frequency domain coefficients, and coded bits of the extended layer coding signal, and then transmitting to a decoding end.