filename | src/aica/audio.h |
changeset | 1024:c67f2d61ab97 |
prev | 759:f16975739abc |
next | 1089:a3984d242909 |
author | nkeynes |
date | Sun Jul 05 13:54:48 2009 +1000 (14 years ago) |
permissions | -rw-r--r-- |
last change | No-op merge lxdream-mem to tip to remove head (Long since merged in actuality) |
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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 "gettext.h"
25 #include "plugin.h"
27 #ifdef __cplusplus
28 extern "C" {
29 #endif
31 #define AUDIO_CHANNEL_COUNT 64
33 #define AUDIO_FMT_8BIT 0
34 #define AUDIO_FMT_16BIT 1
35 #define AUDIO_FMT_ADPCM 2
36 #define AUDIO_FMT_FLOAT 3 // 32-bit -1.0 to 1.0
37 #define AUDIO_FMT_MONO 0
38 #define AUDIO_FMT_STEREO 4
39 #define AUDIO_FMT_SIGNED 0
40 #define AUDIO_FMT_UNSIGNED 8
42 #define AUDIO_FMT_SAMPLE_MASK 3
44 #define AUDIO_FMT_16ST (AUDIO_FMT_16BIT|AUDIO_FMT_STEREO)
45 #define AUDIO_FMT_FLOATST (AUDIO_FMT_FLOAT|AUDIO_FMT_STEREO)
47 #define DEFAULT_SAMPLE_RATE 44100
48 #define DEFAULT_SAMPLE_FORMAT AUDIO_FMT_16ST
50 typedef enum { LOOP_OFF = 0, LOOP_ON = 1, LOOP_LOOPED = 2 } loop_t;
52 typedef struct audio_channel {
53 gboolean active;
54 uint32_t posn; /* current sample #, 0 = first sample */
55 uint32_t posn_left;
56 uint32_t start;
57 uint32_t end;
58 loop_t loop;
59 uint32_t loop_start;
60 int vol; /* 0..255 */
61 int pan; /* 0 (left) .. 31 (right) */
62 uint32_t sample_rate;
63 int sample_format;
64 /* Envelope etc stuff */
65 /* ADPCM */
66 int adpcm_step;
67 int adpcm_predict;
68 } *audio_channel_t;
71 typedef struct audio_buffer {
72 uint32_t length; /* Bytes */
73 uint32_t posn; /* Bytes */
74 int status;
75 char data[0];
76 } *audio_buffer_t;
78 typedef struct audio_driver {
79 const char *name;
80 const char *description;
81 int priority; /* Lower == higher priority */
82 uint32_t sample_rate;
83 uint32_t sample_format;
84 gboolean (*init)( );
85 void (*start)( );
86 gboolean (*process_buffer)( audio_buffer_t buffer );
87 void (*stop)( );
88 gboolean (*shutdown)( );
89 } *audio_driver_t;
92 /**
93 * Print the configured audio drivers to the output stream, one to a line.
94 */
95 void print_audio_drivers( FILE *out );
97 audio_driver_t get_audio_driver_by_name( const char *name );
99 /**
100 * Set the output driver, sample rate and format. Also initializes the
101 * output buffers, flushing any current data and reallocating as
102 * necessary. Must be called before attempting to generate any audio.
103 */
104 gboolean audio_set_driver( audio_driver_t driver );
106 /**
107 * Initialize the audio driver, using the specified driver if available.
108 */
109 audio_driver_t audio_init_driver( const char *preferred_driver );
111 /**
112 * Add a new audio driver to the available drivers list
113 */
114 gboolean audio_register_driver( audio_driver_t driver );
116 /**
117 * Signal the audio driver that playback is beginning
118 */
119 void audio_start_driver();
121 /**
122 * Signal the audio driver that playback is stopping
123 */
124 void audio_stop_driver();
126 /**
127 * Mark the current write buffer as full and prepare the next buffer for
128 * writing. Returns the next buffer to write to.
129 * If all buffers are full, returns NULL.
130 */
131 audio_buffer_t audio_next_write_buffer();
133 /**
134 * Mark the current read buffer as empty and return the next buffer for
135 * reading. If there is no next buffer yet, returns NULL.
136 */
137 audio_buffer_t audio_next_read_buffer();
139 /**
140 * Mix a single output sample and append it to the output buffers
141 */
142 void audio_mix_samples( int num_samples );
144 /**
145 * Retrieve the channel information for the channel, numbered 0..63.
146 */
147 audio_channel_t audio_get_channel( int channel );
149 void audio_start_stop_channel( int channel, gboolean start );
150 void audio_start_channel( int channel );
151 void audio_stop_channel( int channel );
153 void audio_save_state( FILE *f );
154 int audio_load_state( FILE *f );
156 #ifdef __cplusplus
157 }
158 #endif
160 #endif /* !lxdream_audio_H */
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