Search
lxdream.org :: lxdream/src/aica/audio.h
lxdream 0.9.1
released Jun 29
Download Now
filename src/aica/audio.h
changeset 700:4650d0c7f6f9
prev697:479b8c213f61
next736:a02d1475ccfd
author nkeynes
date Sun Jun 22 06:49:00 2008 +0000 (13 years ago)
permissions -rw-r--r--
last change Big cleanup of the command-line options
Add an actual manpage (*gasp*)
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 dream_audio_H
    19 #define dream_audio_H 1
    21 #include <stdint.h>
    22 #include <stdio.h>
    23 #include <glib/gtypes.h>
    24 #include <glib/gi18n.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     char *name;
    80     char *description;
    81     uint32_t sample_rate;
    82     uint32_t sample_format;
    83     gboolean (*init)( );
    84     void (*start)( );
    85     gboolean (*process_buffer)( audio_buffer_t buffer );
    86     void (*stop)( );
    87     gboolean (*shutdown)(  );
    88 } *audio_driver_t;
    91 /**
    92  * Print the configured audio drivers to the output stream, one to a line.
    93  */
    94 void print_audio_drivers( FILE *out );
    96 audio_driver_t get_audio_driver_by_name( const char *name );
    98 /**
    99  * Set the output driver, sample rate and format. Also initializes the 
   100  * output buffers, flushing any current data and reallocating as 
   101  * necessary. Must be called before attempting to generate any audio.
   102  */
   103 gboolean audio_set_driver( audio_driver_t driver );
   105 /**
   106  * Mark the current write buffer as full and prepare the next buffer for
   107  * writing. Returns the next buffer to write to.
   108  * If all buffers are full, returns NULL.
   109  */
   110 audio_buffer_t audio_next_write_buffer();
   112 /**
   113  * Mark the current read buffer as empty and return the next buffer for
   114  * reading. If there is no next buffer yet, returns NULL.
   115  */
   116 audio_buffer_t audio_next_read_buffer();
   118 /**
   119  * Mix a single output sample and append it to the output buffers
   120  */
   121 void audio_mix_samples( int num_samples );
   123 /**
   124  * Retrieve the channel information for the channel, numbered 0..63. 
   125  */
   126 audio_channel_t audio_get_channel( int channel );
   128 void audio_start_stop_channel( int channel, gboolean start );
   129 void audio_start_channel( int channel );
   130 void audio_stop_channel( int channel );
   132 void audio_save_state( FILE *f );
   133 int audio_load_state( FILE *f );
   135 #ifdef __cplusplus
   136 }
   137 #endif
   138 #endif
.