FIELD: physics, acoustics.
SUBSTANCE: invention relates to audio encoding and decoding technology, particularly to hierarchical audio encoding and decoding and hierarchical audio encoding and decoding for transient signals. The hierarchical audio encoding method comprises performing a transient detection on an audio signal of a current frame; performing a time-frequency transform; quantising and encoding amplitude envelope values of core layer encoding sub-bands and extended layer encoding sub-bands; quantising and encoding core layer frequency-domain coefficients; inversely quantising the frequency-domain coefficients in the core layer which are performed with a vector quantisation; performing a difference calculation with original frequency-domain coefficients to obtain a core layer difference signal; and calculating amplitude envelope quantisation indices of the core layer difference signals; quantising and encoding the extended layer encoding signals; multiplexing and packeting the amplitude envelope encoded bits of the core layer encoding sub-bands and the extended layer encoding sub-bands, the encoded bits of the core layer frequency-domain coefficients and the encoded bits of the extended layer coding signals, and then transmitting to a decoding end.
EFFECT: high quality of hierarchical encoding and decoding.
18 cl, 9 dwg, 11 tbl
