melp_sub.h

2400bps MELP语音编解码源程序。

/*

2.4 kbps MELP Proposed Federal Standard speech coder

Fixed-point C code, version 1.0

Copyright (c) 1998, Texas Instruments, Inc.  

Texas Instruments has intellectual property rights on the MELP
algorithm.  The Texas Instruments contact for licensing issues for
commercial and non-government use is William Gordon, Director,
Government Contracts, Texas Instruments Incorporated, Semiconductor
Group (phone [phone]).

The fixed-point version of the voice codec Mixed Excitation Linear
Prediction (MELP) is based on specifications on the C-language software
simulation contained in GSM 06.06 which is protected by copyright and
is the property of the European Telecommunications Standards Institute
(ETSI). This standard is available from the ETSI publication office
tel. [phone]. ETSI has granted a license to United States
Department of Defense to use the C-language software simulation contained
in GSM 06.06 for the purposes of the development of a fixed-point
version of the voice codec Mixed Excitation Linear Prediction (MELP).
Requests for authorization to make other use of the GSM 06.06 or
otherwise distribute or modify them need to be addressed to the ETSI
Secretariat fax: [phone].

*/
/* 

  melp_sub.h: include file for MELP subroutines

*/

#ifndef _melp_sub_h
#define _melp_sub_h_

void bpvc_ana(Shortword speech[], Shortword fpitch[], Shortword bpvc[], 
	      Shortword pitch[]);
void bpvc_ana_init(Shortword fr, Shortword pmin, Shortword pmax, 
		   Shortword nbands, Shortword num_p, Shortword lmin);
void dc_rmv(Shortword sigin[],Shortword sigout[],Shortword delin[],
	    Shortword delout_hi[],Shortword delout_lo[],
	    Shortword frame);
Shortword gain_ana(Shortword sigin[], Shortword pitch, 
		   Shortword minlength, Shortword maxlength);
Shortword lin_int_bnd(Shortword x,Shortword xmin,Shortword xmax,
		      Shortword ymin,Shortword ymax);
void noise_est(Shortword gain,Shortword *noise_gain,Shortword up,
	       Shortword down,Shortword min,Shortword max);
void noise_sup(Shortword *gain,Shortword noise_gain,Shortword max_noise,
	       Shortword max_atten,Shortword nfact);
Shortword q_bpvc(Shortword *bpvc,Shortword *bpvc_index,Shortword bpthresh,
		 Shortword num_bands);
void q_bpvc_dec(Shortword *bpvc,Shortword *bpvc_index,Shortword uv_flag,
		Shortword num_bands);
void q_gain(Shortword *gain,Shortword *gain_index,Shortword qlow,
	    Shortword qup,Shortword qlev,Shortword qlev_q,
	    Shortword double_flag,Shortword scale);
void q_gain_dec(Shortword *gain,Shortword *gain_index,Shortword qlow,
		Shortword qup,Shortword qlev_q,Shortword scale);
void scale_adj(Shortword *speech, Shortword gain, Shortword *prev_scale, 
	       Shortword length, Shortword scaleover, 
	       Shortword inv_scaleover);

#endif