lxdream 0.9.1| filename | src/aica/audio.h |
| changeset | 434:8af49a412d92 |
| prev | 111:230243c2b520 |
| next | 463:0655796f9bb5 |
| author | nkeynes |
| date | Thu Oct 11 08:22:03 2007 +0000 (16 years ago) |
| permissions | -rw-r--r-- |
| last change | Add speed meter to main window Add sunken border around video area Add debugger menu item Move logging out to util.c |
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1 /**
2 * $Id: audio.h,v 1.8 2007-10-09 11:37:36 nkeynes Exp $
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 dream_audio_H
19 #define dream_audio_H 1
21 #include <stdint.h>
22 #include <glib/gtypes.h>
24 #ifdef __cplusplus
25 extern "C" {
26 #endif
28 #define AUDIO_FMT_8BIT 0
29 #define AUDIO_FMT_16BIT 1
30 #define AUDIO_FMT_ADPCM 2
31 #define AUDIO_FMT_MONO 0
32 #define AUDIO_FMT_STEREO 4
33 #define AUDIO_FMT_SIGNED 0
34 #define AUDIO_FMT_UNSIGNED 8
36 #define AUDIO_FMT_16ST (AUDIO_FMT_16BIT|AUDIO_FMT_STEREO)
38 typedef struct audio_channel {
39 gboolean active;
40 uint32_t posn; /* current sample #, 0 = first sample */
41 uint32_t posn_left;
42 uint32_t start;
43 uint32_t end;
44 gboolean loop;
45 uint32_t loop_start;
46 int vol; /* 0..255 */
47 int pan; /* 0 (left) .. 31 (right) */
48 uint32_t sample_rate;
49 int sample_format;
50 /* Envelope etc stuff */
51 /* ADPCM */
52 int adpcm_step;
53 int adpcm_predict;
54 } *audio_channel_t;
57 typedef struct audio_buffer {
58 uint32_t length; /* Bytes */
59 uint32_t posn; /* Bytes */
60 int status;
61 char data[0];
62 } *audio_buffer_t;
64 typedef struct audio_driver {
65 char *name;
66 gboolean (*set_output_format)( uint32_t sample_rate, uint32_t format );
67 gboolean (*process_buffer)( audio_buffer_t buffer );
68 } *audio_driver_t;
70 extern struct audio_driver audio_null_driver;
71 extern struct audio_driver audio_esd_driver;
73 /**
74 * Set the output driver, sample rate and format. Also initializes the
75 * output buffers, flushing any current data and reallocating as
76 * necessary. Must be called before attempting to generate any audio.
77 */
78 gboolean audio_set_driver( audio_driver_t driver, uint32_t samplerate,
79 int format );
81 /**
82 * Mark the current write buffer as full and prepare the next buffer for
83 * writing. Returns the next buffer to write to.
84 * If all buffers are full, returns NULL.
85 */
86 audio_buffer_t audio_next_write_buffer();
88 /**
89 * Mark the current read buffer as empty and return the next buffer for
90 * reading. If there is no next buffer yet, returns NULL.
91 */
92 audio_buffer_t audio_next_read_buffer();
94 /**
95 * Mix a single output sample and append it to the output buffers
96 */
97 void audio_mix_samples( int num_samples );
99 /**
100 * Retrieve the channel information for the channel, numbered 0..63.
101 */
102 audio_channel_t audio_get_channel( int channel );
104 void audio_start_stop_channel( int channel, gboolean start );
105 void audio_start_channel( int channel );
106 void audio_stop_channel( int channel );
109 #ifdef __cplusplus
110 }
111 #endif
112 #endif
.