audio_cnv.h

MIDI解码程序(用VC编写)

/*
    TiMidity++ -- MIDI to WAVE converter and player
    Copyright (C) 1999-2002 Masanao Izumo <[e-mail]>
    Copyright (C) 1995 Tuukka Toivonen <[e-mail]>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    audio_cnv.h

    Audio conversion for U-law, A-law, linear pcm 16-bit.
    Final update: Thu Feb 22 1996
*/

#ifndef ___AUDIO_CNV_H_
#define ___AUDIO_CNV_H_

extern const char  u2c_table[256];
extern const char  c2u_table[256];
extern const char  a2c_table[256];
extern const char  c2a_table[256];
extern const short u2s_table[256];
extern const char  s2u_table[16384];
extern const short a2s_table[256];
extern const char  s2a_table[16384];
extern const char  u2a_table[256];
extern const char  a2u_table[256];

/* U-law-8bit <---> linear-8bit */
#define	AUDIO_U2C(X)	(u2c_table[(unsigned char)(X)])
#define	AUDIO_C2U(X)	(c2u_table[(unsigned char)(X)])
extern void convert_u2c(const char *src, char *tar, int n);
extern void convert_c2u(const char *src, char *tar, int n);

/* A-law-8bit <---> linear-8bit */
#define	AUDIO_A2C(X)	(a2c_table[(unsigned char)(X)])
#define	AUDIO_C2A(X)	(c2a_table[(unsigned char)(X)])
extern void convert_a2c(const char *src, char *tar, int n);
extern void convert_c2a(const char *src, char *tar, int n);

/* U-law-8bit <---> linear-16bit */
#define AUDIO_U2S(X) (u2s_table[(unsigned char)(X)])
#define AUDIO_S2U(X) (s2u_table[((X) >> 2) & 0x3fff])
extern void convert_u2s(const char *src, short *tar, int n);
extern void convert_s2u(const short *src, char *tar, int n);

/* A-law-8bit <---> linear-16bit */
#define AUDIO_A2S(X) (a2s_table[(unsigned char)(X)])
#define AUDIO_S2A(X) (s2a_table[((X) >> 2) & 0x3fff])
extern void convert_a2s(const char *src, short *tar, int n);
extern void convert_s2a(const short *src, char *tar, int n);

/* U-law-8bit <---> A-law-8bit */
#define AUDIO_U2A(X) (u2a_table[(unsigned char)(X)])
#define AUDIO_A2U(X) (a2u_table[(unsigned char)(X)])
extern void convert_u2a(const char *src, char *tar, int n);
extern void convert_a2u(const char *src, char *tar, int n);

/*
 * U: U-law
 * A: A-law
 * C: signed 8-bit
 * S: signed 16-bit
 */

#endif /* ___AUDIO_CNV_H_ */