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lxdream.org :: lxdream/src/aica/audio.h
lxdream 0.9.1
released Jun 29
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filename src/aica/audio.h
changeset 736:a02d1475ccfd
prev700:4650d0c7f6f9
next755:ab873907b00e
author nkeynes
date Mon Jul 14 07:44:42 2008 +0000 (12 years ago)
permissions -rw-r--r--
last change Re-indent everything consistently
Fix include guards for consistency as well
view annotate diff log raw
     1 /**
     2  * $Id$
     3  * 
     4  * Audio engine, ie the part that does the actual work.
     5  *
     6  * Copyright (c) 2005 Nathan Keynes.
     7  *
     8  * This program is free software; you can redistribute it and/or modify
     9  * it under the terms of the GNU General Public License as published by
    10  * the Free Software Foundation; either version 2 of the License, or
    11  * (at your option) any later version.
    12  *
    13  * This program is distributed in the hope that it will be useful,
    14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16  * GNU General Public License for more details.
    17  */
    18 #ifndef lxdream_audio_H
    19 #define lxdream_audio_H 1
    21 #include <stdint.h>
    22 #include <stdio.h>
    23 #include <glib/gtypes.h>
    24 #include <glib/gi18n.h>
    26 #ifdef __cplusplus
    27 extern "C" {
    28 #endif
    30 #define AUDIO_CHANNEL_COUNT 64
    32 #define AUDIO_FMT_8BIT 0
    33 #define AUDIO_FMT_16BIT 1
    34 #define AUDIO_FMT_ADPCM 2
    35 #define AUDIO_FMT_FLOAT 3  // 32-bit -1.0 to 1.0
    36 #define AUDIO_FMT_MONO 0
    37 #define AUDIO_FMT_STEREO 4
    38 #define AUDIO_FMT_SIGNED 0
    39 #define AUDIO_FMT_UNSIGNED 8
    41 #define AUDIO_FMT_SAMPLE_MASK 3
    43 #define AUDIO_FMT_16ST (AUDIO_FMT_16BIT|AUDIO_FMT_STEREO)
    44 #define AUDIO_FMT_FLOATST (AUDIO_FMT_FLOAT|AUDIO_FMT_STEREO)
    46 #define DEFAULT_SAMPLE_RATE 44100
    47 #define DEFAULT_SAMPLE_FORMAT AUDIO_FMT_16ST
    49 typedef enum { LOOP_OFF = 0, LOOP_ON = 1, LOOP_LOOPED = 2 } loop_t;
    51 typedef struct audio_channel {
    52     gboolean active;
    53     uint32_t posn; /* current sample #, 0 = first sample */
    54     uint32_t posn_left;
    55     uint32_t start;
    56     uint32_t end;
    57     loop_t loop;
    58     uint32_t loop_start;
    59     int vol; /* 0..255 */
    60     int pan; /* 0 (left) .. 31 (right) */
    61     uint32_t sample_rate;
    62     int sample_format; 
    63     /* Envelope etc stuff */
    64     /* ADPCM */
    65     int adpcm_step;
    66     int adpcm_predict;
    67 } *audio_channel_t;
    70 typedef struct audio_buffer {
    71     uint32_t length; /* Bytes */
    72     uint32_t posn; /* Bytes */
    73     int status;
    74     char data[0];
    75 } *audio_buffer_t;
    77 typedef struct audio_driver {
    78     char *name;
    79     char *description;
    80     uint32_t sample_rate;
    81     uint32_t sample_format;
    82     gboolean (*init)( );
    83     void (*start)( );
    84     gboolean (*process_buffer)( audio_buffer_t buffer );
    85     void (*stop)( );
    86     gboolean (*shutdown)(  );
    87 } *audio_driver_t;
    90 /**
    91  * Print the configured audio drivers to the output stream, one to a line.
    92  */
    93 void print_audio_drivers( FILE *out );
    95 audio_driver_t get_audio_driver_by_name( const char *name );
    97 /**
    98  * Set the output driver, sample rate and format. Also initializes the 
    99  * output buffers, flushing any current data and reallocating as 
   100  * necessary. Must be called before attempting to generate any audio.
   101  */
   102 gboolean audio_set_driver( audio_driver_t driver );
   104 /**
   105  * Mark the current write buffer as full and prepare the next buffer for
   106  * writing. Returns the next buffer to write to.
   107  * If all buffers are full, returns NULL.
   108  */
   109 audio_buffer_t audio_next_write_buffer();
   111 /**
   112  * Mark the current read buffer as empty and return the next buffer for
   113  * reading. If there is no next buffer yet, returns NULL.
   114  */
   115 audio_buffer_t audio_next_read_buffer();
   117 /**
   118  * Mix a single output sample and append it to the output buffers
   119  */
   120 void audio_mix_samples( int num_samples );
   122 /**
   123  * Retrieve the channel information for the channel, numbered 0..63. 
   124  */
   125 audio_channel_t audio_get_channel( int channel );
   127 void audio_start_stop_channel( int channel, gboolean start );
   128 void audio_start_channel( int channel );
   129 void audio_stop_channel( int channel );
   131 void audio_save_state( FILE *f );
   132 int audio_load_state( FILE *f );
   134 #ifdef __cplusplus
   135 }
   136 #endif
   138 #endif /* !lxdream_audio_H */
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