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audio.h

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/***************************************************************************
 *   Copyright (C) 2006 by André Lindhjem <belgarat@sdf.lonestar.org>,     *
 *                         Kjetil Holien <kjetil.holien@gmail.com>,        *
 *                         Terje Risa <terje.risa@gmail.com> &             *
 *                         Øyvind Nerbråten <oyvind@nerbraten.com>         *
 *                                                                         *
 *   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.             *
 ***************************************************************************
 *
 * \file audio.h
 * \author André Lindhjem, Kjetil Holien, Terje Risa & Øyvind Nerbråten
 * \date 25.02.2006
 * 
 * Audio module. This handles the task of reading audio files and playing
 * the audio output. It uses a MP3-decoder and libao, and it can easilly be
 * extended with more decoders.
 */


#ifndef AUDIO_H_
#define AUDIO_H_

#include <mad.h>        /* mad_timer_t */
#include <ao/ao.h>      /* ao_sample_format */
#include <sys/stat.h>   /* file stat */
#include <pthread.h>

#include "daisylibao.h"
#include "libdaisy.h"


/* ************************************************ *
 *  Global type definitions and datastructures      *
 * ************************************************ */

typedef void * audio_data_t;

typedef enum AUDIO_FILE_TYPE 
{
    AUDIO_FILE_WAV,             /* PCM WAVE file */
    AUDIO_FILE_MP3,             /* MP3 file. uses mp3.h */
    AUDIO_FILE_AAC,             /* AAC file. uses aac.h */
    AUDIO_FILE_UNKNOWN          /* Unknown filetype */
} audio_file_t;

typedef enum {
    AUDIO_STATE_PLAY,
    AUDIO_STATE_PAUSE,
    AUDIO_STATE_STOP,
    AUDIO_STATE_NOOP
} audio_state_t;

typedef struct
{
    /* buffer */
    struct buffer
    {
        unsigned char const *buffer_start;
        unsigned long buffer_length;
    } buffer;

    char            *file_name;         /* the file_name of the file we have loaded */
    char            *prev_file_name;    /* the previous file_name. we check against this so that we won't have to reload already opened files */

    int             fd;                 /* input file descriptor */
    void            *fdm;               /* pointer to file mmap */
    struct stat     stat;               /* file stats */

    audio_file_t    file_type;          /* the file_type (mp3, aac, wav) */
    audio_file_t    prev_file_type;     /* the previous file_type */

    ao_sample_format format;            /* the format of our output samples. we use this to initialize ao */

    /* mad_timer_t variables to keep track of progress, start and stop-times. */
    /* TODO: We'll have to use this for all decoders. Define our own struct in audio.h and use this instead? This should be fixed before additional decoders are implemented. */
    mad_timer_t     progress;
    mad_timer_t     start;
    mad_timer_t     stop;

    audio_state_t state;
    bool is_playing;
    
    bool first_run; /* we use this to find out if a decoder iteration is our first or not. */
    
    /* thread data */
    pthread_mutex_t     mutex;          /* we need to prevent race conditions on shared variables */
    pthread_cond_t      unpause_cond;
    
    /* callback functions */
    void (*cb_playing_done) (daisyplayer_t d);  /* audio done callback function */
    bool do_callback_done;                      /* set to true to run cb_playing_done once */
    void (*cb_error) (void *data, enum daisy_status, const char *); /* error callback */
    void (*cb_progress) (void *data, long int progress_ms); /* progress callback */
    
    daisyplayer_t *daisy;               /* this will need to be passed along when callback function cb_playing_done is called */

    struct audio_dither *mp3_dither;    /* Dither struct. This is used by the mp3.c dither routine */
    
    ao_device *device;                  /* device is used by ao. */
    
    unsigned int magic;                 /* magic number */
} struct_audio_data_t;



/* ************************************************ *
 *          Global function declarations            *
 * ************************************************ */

unsigned
long
int audio_play (audio_data_t _data, const char *fname, const char *start, const char *stop);

int audio_pause (audio_data_t _data);

int audio_stop (audio_data_t _data);

int callback (audio_data_t _data, long int);
 
void audio_terminate (audio_data_t _data);

audio_data_t audio_initiate (daisyplayer_t daisy,
                             void (*done) (daisyplayer_t d),
                             void (*error) (void *data, enum daisy_status, const char *),
                             void (*progress) (void *data, long int progress_ms));

void *audio_thread (void *_data);

audio_state_t audio_get_state (audio_data_t _data);

#endif /* AUDIO_H_ */

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