fluid_sfont.h

/* FluidSynth - A Software Synthesizer
 *
 * Copyright (C) 2003  Peter Hanappe and others.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */


#ifndef _PRIV_FLUID_SFONT_H
#define _PRIV_FLUID_SFONT_H

#include "fluidsynth.h"

int fluid_sample_validate(fluid_sample_t *sample, unsigned int max_end);
int fluid_sample_sanitize_loop(fluid_sample_t *sample, unsigned int max_end);

/*
 * Utility macros to access soundfonts, presets, and samples
 */

#define fluid_sfloader_delete(_loader) { if ((_loader) && (_loader)->free) (*(_loader)->free)(_loader); }
#define fluid_sfloader_load(_loader, _filename) (*(_loader)->load)(_loader, _filename)


#define fluid_sfont_delete_internal(_sf)   ( ((_sf) && (_sf)->free)? (*(_sf)->free)(_sf) : 0)


#define fluid_preset_delete_internal(_preset) \
  { if ((_preset) && (_preset)->free) { (*(_preset)->free)(_preset); }}

#define fluid_preset_noteon(_preset,_synth,_ch,_key,_vel) \
  (*(_preset)->noteon)(_preset,_synth,_ch,_key,_vel)

#define fluid_preset_notify(_preset,_reason,_chan) \
  ( ((_preset) && (_preset)->notify) ? (*(_preset)->notify)(_preset,_reason,_chan) : FLUID_OK )


#define fluid_sample_incr_ref(_sample) { (_sample)->refcount++; }

#define fluid_sample_decr_ref(_sample) \
  (_sample)->refcount--; \
  if (((_sample)->refcount == 0) && ((_sample)->notify)) \
    (*(_sample)->notify)(_sample, FLUID_SAMPLE_DONE);



/**
 * File callback structure to enable custom soundfont loading (e.g. from memory).
 */
struct _fluid_file_callbacks_t
{
    fluid_sfloader_callback_open_t  fopen;
    fluid_sfloader_callback_read_t  fread;
    fluid_sfloader_callback_seek_t  fseek;
    fluid_sfloader_callback_close_t fclose;
    fluid_sfloader_callback_tell_t  ftell;
};

/**
 * SoundFont loader structure.
 */
struct _fluid_sfloader_t
{
    void *data;           /**< User defined data pointer used by _fluid_sfloader_t::load() */

    /** Callback structure specifying file operations used during soundfont loading to allow custom loading, such as from memory */
    fluid_file_callbacks_t file_callbacks;

    fluid_sfloader_free_t free;

    fluid_sfloader_load_t load;
};

/**
 * Virtual SoundFont instance structure.
 */
struct _fluid_sfont_t
{
    void *data;           /**< User defined data */
    int id;               /**< SoundFont ID */
    int refcount;         /**< SoundFont reference count (1 if no presets referencing it) */
    int bankofs;          /**< Bank offset */

    fluid_sfont_free_t free;

    fluid_sfont_get_name_t get_name;

    fluid_sfont_get_preset_t get_preset;

    fluid_sfont_iteration_start_t iteration_start;

    fluid_sfont_iteration_next_t iteration_next;
};

/**
 * Virtual SoundFont preset.
 */
struct _fluid_preset_t
{
    void *data;                                   /**< User supplied data */
    fluid_sfont_t *sfont;                         /**< Parent virtual SoundFont */

    fluid_preset_free_t free;

    fluid_preset_get_name_t get_name;

    fluid_preset_get_banknum_t get_banknum;

    fluid_preset_get_num_t get_num;

    fluid_preset_noteon_t noteon;

    /**
     * Virtual SoundFont preset notify method.
     * @param preset Virtual SoundFont preset
     * @param reason #FLUID_PRESET_SELECTED or #FLUID_PRESET_UNSELECTED
     * @param chan MIDI channel number
     * @return Should return #FLUID_OK
     *
     * Implement this optional method if the preset needs to be notified about
     * preset select and unselect events.
     *
     * This method may be called from within synthesis context and therefore
     * should be as efficient as possible and not perform any operations considered
     * bad for realtime audio output (memory allocations and other OS calls).
     */
    int (*notify)(fluid_preset_t *preset, int reason, int chan);
};

/**
 * Virtual SoundFont sample.
 */
struct _fluid_sample_t
{
    char name[21];                /**< Sample name */

    /* The following four sample pointers store the original pointers from the Soundfont
     * file. They are never changed after loading and are used to re-create the
     * actual sample pointers after a sample has been unloaded and loaded again. The
     * actual sample pointers get modified during loading for SF3 (compressed) samples
     * and individually loaded SF2 samples. */
    unsigned int source_start;
    unsigned int source_end;
    unsigned int source_loopstart;
    unsigned int source_loopend;

    unsigned int start;           /**< Start index */
    unsigned int end;	        /**< End index, index of last valid sample point (contrary to SF spec) */
    unsigned int loopstart;       /**< Loop start index */
    unsigned int loopend;         /**< Loop end index, first point following the loop (superimposed on loopstart) */

    unsigned int samplerate;      /**< Sample rate */
    int origpitch;                /**< Original pitch (MIDI note number, 0-127) */
    int pitchadj;                 /**< Fine pitch adjustment (+/- 99 cents) */
    int sampletype;               /**< Specifies the type of this sample as indicated by the #fluid_sample_type enum */
    int auto_free;                /**< TRUE if _fluid_sample_t::data and _fluid_sample_t::data24 should be freed upon sample destruction */
    short *data;                  /**< Pointer to the sample's 16 bit PCM data */
    char *data24;                 /**< If not NULL, pointer to the least significant byte counterparts of each sample data point in order to create 24 bit audio samples */

    int amplitude_that_reaches_noise_floor_is_valid;      /**< Indicates if \a amplitude_that_reaches_noise_floor is valid (TRUE), set to FALSE initially to calculate. */
    double amplitude_that_reaches_noise_floor;            /**< The amplitude at which the sample's loop will be below the noise floor.  For voice off optimization, calculated automatically. */

    unsigned int refcount;        /**< Count of voices using this sample */
    int preset_count;             /**< Count of selected presets using this sample (used for dynamic sample loading) */

    /**
     * Implement this function to receive notification when sample is no longer used.
     * @param sample Virtual SoundFont sample
     * @param reason #FLUID_SAMPLE_DONE only currently
     * @return Should return #FLUID_OK
     */
    int (*notify)(fluid_sample_t *sample, int reason);
};


#endif /* _PRIV_FLUID_SFONT_H */