Encoding device, decoding device, and methods therefor

摘要

Disclosed is an encoding device that improves the quality of a decoded signal in a hierarchical coding (scalable coding) method, wherein a band to be quantized is selected for every level (layer). The encoding device (101) is equipped with a second layer encoding unit (205) that selects a first band to be quantized of a first input signal from among a plurality of sub-bands, and that generates second layer encoding information containing first band information of said band; a second layer decoding unit (206) that generates a first decoded signal using the second layer encoding information; an addition unit (207) that generates a second input signal using the first input signal and the first decoded signal; and a third layer encoding unit (208) that selects a second band to be quantized of the second input signal using the first decoded signal, and that generates third layer encoding information.

主权项

1. A coding apparatus that includes at least two coding layers, the coding apparatus comprising a circuit, the circuit comprising:
a first layer coding section that receives a first speech input signal of a frequency domain, selects a first quantization target band of the first speech input signal from a plurality of sub-bands into which the frequency domain is divided, encodes the first speech input signal of the first quantization target band to generate first coded information including first band information on the first quantization target band, generates a first decoded signal using the first coded information, and generates a second speech input signal using the first speech input signal and the first decoded signal; and a second layer coding section that receives the second speech input signal and the first decoded signal or the first coded information, selects a second quantization target band of the second speech input signal from the plurality of sub-bands using the first decoded signal or the first coded information, encodes the second speech input signal of the second quantization target band, and generates second coded information including second band information on the second quantization target band, wherein the second layer coding section selects the second quantization target band by relatively undervaluing weighting related to a degree of importance to the first quantization target band with respect to a first quantization target band included in the first coded information and a band except the first quantization target band.