lxdream 0.9.1| filename | src/aica/audio.h |
| changeset | 66:2ec5b6eb75e5 |
| next | 73:0bb57e51ac9e |
| author | nkeynes |
| date | Tue Jan 10 13:56:54 2006 +0000 (18 years ago) |
| permissions | -rw-r--r-- |
| last change | Go go gadget audio! Slow, but it works :) |
| view | annotate | diff | log | raw |
1 /**
2 * $Id: audio.h,v 1.1 2006-01-10 13:56:54 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
37 typedef struct audio_channel {
38 gboolean active;
39 uint32_t posn;
40 uint32_t posn_left;
41 uint32_t start;
42 uint32_t end;
43 uint32_t loop_start;
44 uint32_t loop_end;
45 int loop_count; /* 0 = no loop, -1 = loop forever */
46 int vol_left; /* 0..255 */
47 int vol_right; /* 0..255 */
48 uint32_t sample_rate;
49 int sample_format;
50 /* Envelope etc stuff */
51 /* ADPCM */
52 int adpcm_nibble; /* 0 = low nibble, 1 = high nibble */
53 int adpcm_step;
54 int adpcm_predict;
55 } *audio_channel_t;
58 typedef struct audio_buffer {
59 uint32_t length; /* Samples */
60 uint32_t posn; /* Samples */
61 int status;
62 char data[0];
63 } *audio_buffer_t;
65 struct audio_driver {
66 gboolean (*set_output_format)( uint32_t sample_rate, uint32_t format );
67 gboolean (*process_buffer)( audio_buffer_t buffer );
68 };
70 typedef struct audio_driver *audio_driver_t;
72 extern struct audio_driver null_audio_driver;
73 extern struct audio_driver esd_audio_driver;
75 /**
76 * Set the output driver, sample rate and format. Also initializes the
77 * output buffers, flushing any current data and reallocating as
78 * necessary. Must be called before attempting to generate any audio.
79 */
80 void audio_set_output( audio_driver_t driver, uint32_t samplerate,
81 int format );
83 /**
84 * Mark the current write buffer as full and prepare the next buffer for
85 * writing. Returns the next buffer to write to.
86 * If all buffers are full, returns NULL.
87 */
88 audio_buffer_t audio_next_write_buffer();
90 /**
91 * Mark the current read buffer as empty and return the next buffer for
92 * reading. If there is no next buffer yet, returns NULL.
93 */
94 audio_buffer_t audio_next_read_buffer();
96 /**
97 * Mix a single output sample and append it to the output buffers
98 */
99 void audio_mix_sample( void );
101 /**
102 * Retrieve the channel information for the channel, numbered 0..63.
103 */
104 audio_channel_t audio_get_channel( int channel );
106 void audio_start_channel( int channel );
107 void audio_stop_channel( int channel );
110 #ifdef __cplusplus
111 }
112 #endif
113 #endif
.