0
|
1 /*
|
|
2 SDL - Simple DirectMedia Layer
|
|
3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
|
|
4
|
|
5 This library is free software; you can redistribute it and/or
|
|
6 modify it under the terms of the GNU Library General Public
|
|
7 License as published by the Free Software Foundation; either
|
|
8 version 2 of the License, or (at your option) any later version.
|
|
9
|
|
10 This library is distributed in the hope that it will be useful,
|
|
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
13 Library General Public License for more details.
|
|
14
|
|
15 You should have received a copy of the GNU Library General Public
|
|
16 License along with this library; if not, write to the Free
|
|
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
18
|
|
19 Sam Lantinga
|
|
20 slouken@devolution.com
|
|
21 */
|
|
22
|
|
23 #ifdef SAVE_RCSID
|
|
24 static char rcsid =
|
|
25 "@(#) $Id$";
|
|
26 #endif
|
|
27
|
|
28 /* Allow access to a raw mixing buffer */
|
|
29
|
|
30 #include <sys/types.h>
|
|
31 #include <stdlib.h>
|
|
32 #include <stdio.h>
|
|
33 #include <string.h>
|
|
34 #include <errno.h>
|
|
35 #include <signal.h>
|
|
36 #include <unistd.h>
|
|
37
|
|
38 #include "SDL_audio.h"
|
|
39 #include "SDL_error.h"
|
|
40 #include "SDL_audiomem.h"
|
|
41 #include "SDL_audio_c.h"
|
|
42 #include "SDL_timer.h"
|
|
43 #include "SDL_audiodev_c.h"
|
|
44 #include "SDL_artsaudio.h"
|
|
45
|
|
46 /* The tag name used by artsc audio */
|
|
47 #define ARTSC_DRIVER_NAME "artsc"
|
|
48
|
|
49 /* Audio driver functions */
|
|
50 static int ARTSC_OpenAudio(_THIS, SDL_AudioSpec *spec);
|
|
51 static void ARTSC_WaitAudio(_THIS);
|
|
52 static void ARTSC_PlayAudio(_THIS);
|
|
53 static Uint8 *ARTSC_GetAudioBuf(_THIS);
|
|
54 static void ARTSC_CloseAudio(_THIS);
|
|
55
|
|
56 /* Audio driver bootstrap functions */
|
|
57
|
|
58 static int Audio_Available(void)
|
|
59 {
|
|
60 if(arts_init())
|
|
61 return 0;
|
|
62 else
|
|
63 return 1;
|
|
64 }
|
|
65
|
|
66 static void Audio_DeleteDevice(SDL_AudioDevice *device)
|
|
67 {
|
|
68 free(device->hidden);
|
|
69 free(device);
|
|
70 }
|
|
71
|
|
72 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
|
|
73 {
|
|
74 SDL_AudioDevice *this;
|
|
75
|
|
76 /* Initialize all variables that we clean on shutdown */
|
|
77 this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
|
|
78 if ( this ) {
|
|
79 memset(this, 0, (sizeof *this));
|
|
80 this->hidden = (struct SDL_PrivateAudioData *)
|
|
81 malloc((sizeof *this->hidden));
|
|
82 }
|
|
83 if ( (this == NULL) || (this->hidden == NULL) ) {
|
|
84 SDL_OutOfMemory();
|
|
85 if ( this ) {
|
|
86 free(this);
|
|
87 }
|
|
88 return(0);
|
|
89 }
|
|
90 memset(this->hidden, 0, (sizeof *this->hidden));
|
|
91 stream = 0;
|
|
92
|
|
93 /* Set the function pointers */
|
|
94 this->OpenAudio = ARTSC_OpenAudio;
|
|
95 this->WaitAudio = ARTSC_WaitAudio;
|
|
96 this->PlayAudio = ARTSC_PlayAudio;
|
|
97 this->GetAudioBuf = ARTSC_GetAudioBuf;
|
|
98 this->CloseAudio = ARTSC_CloseAudio;
|
|
99
|
|
100 this->free = Audio_DeleteDevice;
|
|
101
|
|
102 return this;
|
|
103 }
|
|
104
|
|
105 AudioBootStrap ARTSC_bootstrap = {
|
|
106 ARTSC_DRIVER_NAME, "Analog Realtime Synthesizer",
|
|
107 Audio_Available, Audio_CreateDevice
|
|
108 };
|
|
109
|
|
110 /* This function waits until it is possible to write a full sound buffer */
|
|
111 static void ARTSC_WaitAudio(_THIS)
|
|
112 {
|
|
113 Sint32 ticks;
|
|
114
|
|
115 /* Check to see if the thread-parent process is still alive */
|
|
116 { static int cnt = 0;
|
|
117 /* Note that this only works with thread implementations
|
|
118 that use a different process id for each thread.
|
|
119 */
|
|
120 if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */
|
|
121 if ( kill(parent, 0) < 0 ) {
|
|
122 this->enabled = 0;
|
|
123 }
|
|
124 }
|
|
125 }
|
|
126
|
|
127 /* Use timer for general audio synchronization */
|
|
128 ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS;
|
|
129 if ( ticks > 0 ) {
|
|
130 SDL_Delay(ticks);
|
|
131 }
|
|
132 }
|
|
133
|
|
134 static void ARTSC_PlayAudio(_THIS)
|
|
135 {
|
|
136 int written;
|
|
137
|
|
138 /* Write the audio data */
|
|
139 written = arts_write(stream, mixbuf, mixlen);
|
|
140
|
|
141 /* If timer synchronization is enabled, set the next write frame */
|
|
142 if ( frame_ticks ) {
|
|
143 next_frame += frame_ticks;
|
|
144 }
|
|
145
|
|
146 /* If we couldn't write, assume fatal error for now */
|
|
147 if ( written < 0 ) {
|
|
148 this->enabled = 0;
|
|
149 }
|
|
150 #ifdef DEBUG_AUDIO
|
|
151 fprintf(stderr, "Wrote %d bytes of audio data\n", written);
|
|
152 #endif
|
|
153 }
|
|
154
|
|
155 static Uint8 *ARTSC_GetAudioBuf(_THIS)
|
|
156 {
|
|
157 return(mixbuf);
|
|
158 }
|
|
159
|
|
160 static void ARTSC_CloseAudio(_THIS)
|
|
161 {
|
|
162 if ( mixbuf != NULL ) {
|
|
163 SDL_FreeAudioMem(mixbuf);
|
|
164 mixbuf = NULL;
|
|
165 }
|
|
166 if ( stream ) {
|
|
167 arts_close_stream(stream);
|
|
168 stream = 0;
|
|
169 }
|
|
170 }
|
|
171
|
|
172 static int ARTSC_OpenAudio(_THIS, SDL_AudioSpec *spec)
|
|
173 {
|
|
174 int bits, frag_spec;
|
|
175 Uint16 test_format, format;
|
|
176
|
|
177 /* Reset the timer synchronization flag */
|
|
178 frame_ticks = 0.0;
|
|
179
|
|
180 mixbuf = NULL;
|
|
181
|
|
182 /* Try for a closest match on audio format */
|
|
183 format = 0;
|
|
184 bits = 0;
|
|
185 for ( test_format = SDL_FirstAudioFormat(spec->format);
|
|
186 ! format && test_format; ) {
|
|
187 #ifdef DEBUG_AUDIO
|
|
188 fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
|
|
189 #endif
|
|
190 switch ( test_format ) {
|
|
191 case AUDIO_U8:
|
|
192 bits = 8;
|
|
193 format = 1;
|
|
194 break;
|
|
195 case AUDIO_S16LSB:
|
|
196 bits = 16;
|
|
197 format = 1;
|
|
198 break;
|
|
199 default:
|
|
200 format = 0;
|
|
201 break;
|
|
202 }
|
|
203 if ( ! format ) {
|
|
204 test_format = SDL_NextAudioFormat();
|
|
205 }
|
|
206 }
|
|
207 if ( format == 0 ) {
|
|
208 SDL_SetError("Couldn't find any hardware audio formats");
|
|
209 return(-1);
|
|
210 }
|
|
211 spec->format = test_format;
|
|
212
|
|
213 stream = arts_play_stream(spec->freq, bits, spec->channels, "SDL");
|
|
214
|
|
215 /* Calculate the final parameters for this audio specification */
|
|
216 SDL_CalculateAudioSpec(spec);
|
|
217
|
|
218 /* Determine the power of two of the fragment size */
|
|
219 for ( frag_spec = 0; (0x01<<frag_spec) < spec->size; ++frag_spec );
|
|
220 if ( (0x01<<frag_spec) != spec->size ) {
|
|
221 SDL_SetError("Fragment size must be a power of two");
|
|
222 return(-1);
|
|
223 }
|
|
224 frag_spec |= 0x00020000; /* two fragments, for low latency */
|
|
225
|
|
226 #ifdef ARTS_P_PACKET_SETTINGS
|
|
227 arts_stream_set(stream, ARTS_P_PACKET_SETTINGS, frag_spec);
|
|
228 #else
|
|
229 arts_stream_set(stream, ARTS_P_PACKET_SIZE, frag_spec&0xffff);
|
|
230 arts_stream_set(stream, ARTS_P_PACKET_COUNT, frag_spec>>16);
|
|
231 #endif
|
|
232 spec->size = arts_stream_get(stream, ARTS_P_PACKET_SIZE);
|
|
233
|
|
234 /* Allocate mixing buffer */
|
|
235 mixlen = spec->size;
|
|
236 mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
|
|
237 if ( mixbuf == NULL ) {
|
|
238 return(-1);
|
|
239 }
|
|
240 memset(mixbuf, spec->silence, spec->size);
|
|
241
|
|
242 /* Get the parent process id (we're the parent of the audio thread) */
|
|
243 parent = getpid();
|
|
244
|
|
245 /* We're ready to rock and roll. :-) */
|
|
246 return(0);
|
|
247 }
|