EP 0208712 B1 19930407 - ADAPTIVE METHOD AND APPARATUS FOR CODING SPEECH
Title (en)
ADAPTIVE METHOD AND APPARATUS FOR CODING SPEECH
Publication
Application
Priority
- US 68438284 A 19841220
- US 79817485 A 19851114
Abstract (en)
[origin: WO8603872A1] In a speech encoder, a Fourier transform (28) of the speech is provided. The Fourier transform is equalized (30) by normalizing the spectrum coefficients to a curve which approximates the shape of the spectrum. Both the curve and the equalized spectrum are encoded. In one system, scale factors (45) are generated and encoded for each of a plurality of subbands of a Fourier transform spectrum of speech. Based on those scale factors, the spectrum is equalized (46). Coefficients of a limited number of subbands (48) determined by the scale factors are encoded (50). The number of bits used to encode each coefficient of each transmitted subband is determined by the scale factor for each subband. At the receiver, coefficients of subbands which are not transmitted are approximated by means of a list replication technique (54).
IPC 1-7
IPC 8 full level
G10L 19/02 (2006.01); G10L 21/02 (2006.01); G10L 21/038 (2013.01)
CPC (source: EP)
G10L 21/038 (2013.01)
Citation (examination)
EP 0176243 A2 19860402 - BRITISH TELECOMM [GB]
Designated contracting state (EPC)
BE DE FR GB IT
DOCDB simple family (publication)
WO 8603872 A1 19860703; DE 3587251 D1 19930513; DE 3587251 T2 19930715; EP 0208712 A1 19870121; EP 0208712 A4 19880128; EP 0208712 B1 19930407
DOCDB simple family (application)
US 8502448 W 19851211; DE 3587251 T 19851211; EP 86900480 A 19851211