pit.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].

*/
/*

  pit.h: include file for pitch subroutines
  
*/

#ifndef _pit_h
#define _pit_h_

/* External function definitions */
Shortword double_chk(Shortword sig_in[],Shortword *pcorr,Shortword pitch,
		     Shortword pdouble,Shortword pmin,Shortword pmax,
		     Shortword pmin_q7,Shortword pmax_q7,
		     Shortword lmin);
void double_ver(Shortword sig_in[],Shortword *pcorr,Shortword pitch,
		Shortword pmin,Shortword pmax,Shortword pmin_q7,
		Shortword pmax_q7,Shortword lmin);
Shortword f_pitch_scale(Shortword sig_out[],Shortword sig_in[],
			Shortword length);
Shortword find_pitch(Shortword sig_in[],Shortword *pcorr,Shortword lower,
		     Shortword upper,Shortword length);
Shortword frac_pch(Shortword sig_in[],Shortword *pcorr,Shortword fpitch,
		   Shortword range,Shortword pmin,Shortword pmax,
		   Shortword pmin_q7,Shortword pmax_q7,Shortword lmin);
Shortword p_avg_update(Shortword pitch, Shortword pcorr, Shortword pthresh);
void p_avg_init(Shortword pdecay, Shortword default_pitch, 
		Shortword pdecay_pitch, Shortword num_good);
Shortword pitch_ana(Shortword speech[],Shortword resid[],
		    Shortword pitch_est,Shortword pitch_avg, 
		    Shortword *pcorr2);
void pitch_ana_init(Shortword pmin,Shortword pmax,Shortword fr,
		    Shortword lpf_ord, Shortword lmin);

#endif