praat/external/mp3/mp3.h

#ifndef __MP3_H
#define __MP3_H

/*
 * Praat wrappers for libMAD (MPEG Audio Decoder)
 * Copyright 2007 Erez Volk
 *
 * This code 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 code 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 work. If not, see <http://www.gnu.org/licenses/>.
 */

#include "../../melder/melder.h"   // for integer

/* The following function is used to identify MP3 files */
int mp3_recognize (int nread, const char *data);

/* Actual decoding is done with an MP3_FILE object */
typedef struct _MP3_FILE *MP3_FILE;

typedef int MP3F_SAMPLE;
#if defined (_OFF_T) || defined (__off_t_defined)
	typedef off_t MP3F_OFFSET;
#else
	typedef unsigned long MP3F_OFFSET;
#endif

#define MP3F_MAX_CHANNELS 2
#define MP3F_MAX_SAMPLES  1152 /* Per callback */

typedef void (*MP3F_CALLBACK) (
		const MP3F_SAMPLE *channels [MP3F_MAX_CHANNELS],
		integer num_samples,
		void *context);

MP3_FILE mp3f_new ();
void mp3f_delete (MP3_FILE mp3f);

void mp3f_set_file (MP3_FILE mp3f, FILE *f);

int mp3f_analyze (MP3_FILE mp3f);
unsigned mp3f_channels (MP3_FILE mp3f);
unsigned mp3f_frequency (MP3_FILE mp3f);
MP3F_OFFSET mp3f_samples (MP3_FILE mp3f);

void mp3f_set_callback (MP3_FILE mp3f,
		MP3F_CALLBACK callback, void *context);
int mp3f_seek (MP3_FILE mp3f, MP3F_OFFSET sample);
int mp3f_read (MP3_FILE mp3f, MP3F_OFFSET num_samples);

#define mp3f_sample_to_float(s) ((float)((s) / (float)(1L << 28)))
short mp3f_sample_to_short (MP3F_SAMPLE sample);

#endif /* __MP3_H */