HIERARCHICAL AUDIO FREQUENCY ENCODING AND DECODING METHOD AND SYSTEM, HIERARCHICAL FREQUENCY ENCODING AND DECODING METHOD FOR TRANSIENT SIGNAL

摘要

Hierarchical audio coding and decoding method and system and hierarchical audio coding and decoding method for transient signals are provided. The hierarchical audio coding method comprises: performing a transient detection on an audio signal of a current frame (10); performing a time-domain transform to obtain total frequency-domain coefficients of the current frame (20); quantizing and coding amplitude envelope values of core layer coding sub-bands and extended layer coding sub-bands, to obtain amplitude envelope quantization indexes and coded bits thereof of the core layer coding sub-bands and the extended layer coding sub-bands (30); quantizing and coding core layer frequency-domain coefficients to obtain coded bits of the core layer frequency-domain coefficients (40); performing an inverse quantization on the frequency-domain coefficients in the core layer which are performed with the vector quantization, and performing a difference calculation with original frequency-domain coefficients, to obtain core layer residual signal (50), and calculating the amplitude envelope quantization indexes thereof (60); quantizing and coding extended layer coding signals to obtain coded bits of the extended layer coding signals (70); and multiplexing and packeting the amplitude envelope coded bits of the coding sub-bands of the core layer and the extended layer, the coded bits of the core layer frequency-domain coefficients and the coded bits of the extended layer coding signals, and transmitting to the decoding end (80).