src/audio/dmedia/SDL_irixaudio.c
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FUNCTIONS
This source file includes following functions.
- Audio_Available
- Audio_DeleteDevice
- Audio_CreateDevice
- AL_WaitAudio
- AL_PlayAudio
- AL_GetAudioBuf
- AL_CloseAudio
- AL_OpenAudio
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997, 1998 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 5635-34 Springhouse Dr.
21 Pleasanton, CA 94588 (USA)
22 slouken@devolution.com
23 */
24
25 #ifdef SAVE_RCSID
26 static char rcsid =
27 "@(#) $Id: SDL_irixaudio.c,v 1.1.2.2 2001/01/05 20:13:18 hercules Exp $";
28 #endif
29
30 /* Allow access to a raw mixing buffer (For IRIX 6.5 and higher) */
31
32 #include <stdlib.h>
33
34 #include "SDL_endian.h"
35 #include "SDL_timer.h"
36 #include "SDL_audio.h"
37 #include "SDL_audiomem.h"
38 #include "SDL_audio_c.h"
39 #include "SDL_irixaudio.h"
40
41
42 /* Audio driver functions */
43 static int AL_OpenAudio(_THIS, SDL_AudioSpec *spec);
44 static void AL_WaitAudio(_THIS);
45 static void AL_PlayAudio(_THIS);
46 static Uint8 *AL_GetAudioBuf(_THIS);
47 static void AL_CloseAudio(_THIS);
48
49 /* Audio driver bootstrap functions */
50
51 static int Audio_Available(void)
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52 {
53 return 1;
54 }
55
56 static void Audio_DeleteDevice(SDL_AudioDevice *device)
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57 {
58 free(device->hidden);
59 free(device);
60 }
61
62 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
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63 {
64 SDL_AudioDevice *this;
65
66 /* Initialize all variables that we clean on shutdown */
67 this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
68 if ( this ) {
69 memset(this, 0, (sizeof *this));
70 this->hidden = (struct SDL_PrivateAudioData *)
71 malloc((sizeof *this->hidden));
72 }
73 if ( (this == NULL) || (this->hidden == NULL) ) {
74 SDL_OutOfMemory();
75 if ( this ) {
76 free(this);
77 }
78 return(0);
79 }
80 memset(this->hidden, 0, (sizeof *this->hidden));
81
82 /* Set the function pointers */
83 this->OpenAudio = AL_OpenAudio;
84 this->WaitAudio = AL_WaitAudio;
85 this->PlayAudio = AL_PlayAudio;
86 this->GetAudioBuf = AL_GetAudioBuf;
87 this->CloseAudio = AL_CloseAudio;
88
89 this->free = Audio_DeleteDevice;
90
91 return this;
92 }
93
94 AudioBootStrap AUDIO_bootstrap = {
95 "AL", "IRIX DMedia audio",
96 Audio_Available, Audio_CreateDevice
97 };
98
99
100 void static AL_WaitAudio(_THIS)
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101 {
102 Sint32 timeleft;
103
104 timeleft = this->spec.samples - alGetFillable(audio_port);
105 if ( timeleft > 0 ) {
106 timeleft /= (this->spec.freq/1000);
107 SDL_Delay((Uint32)timeleft);
108 }
109 }
110
111 static void AL_PlayAudio(_THIS)
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112 {
113 /* Write the audio data out */
114 if ( alWriteFrames(audio_port, mixbuf, this->spec.samples) < 0 ) {
115 /* Assume fatal error, for now */
116 this->enabled = 0;
117 }
118 }
119
120 static Uint8 *AL_GetAudioBuf(_THIS)
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121 {
122 return(mixbuf);
123 }
124
125 static void AL_CloseAudio(_THIS)
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126 {
127 if ( mixbuf != NULL ) {
128 SDL_FreeAudioMem(mixbuf);
129 mixbuf = NULL;
130 }
131 if ( audio_port != NULL ) {
132 ALcloseport(audio_port);
133 audio_port = NULL;
134 }
135 }
136
137 static int AL_OpenAudio(_THIS, SDL_AudioSpec *spec)
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138 {
139 ALconfig audio_config;
140 ALpv audio_param;
141 int width;
142
143 /* Determine the audio parameters from the AudioSpec */
144 switch ( spec->format & 0xFF ) {
145
146 case 8: { /* Signed 8 bit audio data */
147 spec->format = AUDIO_S8;
148 width = AL_SAMPLE_8;
149 }
150 break;
151
152 case 16: { /* Signed 16 bit audio data */
153 spec->format = AUDIO_S16MSB;
154 width = AL_SAMPLE_16;
155 }
156 break;
157
158 default: {
159 SDL_SetError("Unsupported audio format");
160 return(-1);
161 }
162 }
163
164 /* Update the fragment size as size in bytes */
165 SDL_CalculateAudioSpec(spec);
166
167 /* Set output frequency */
168 audio_param.param = AL_RATE;
169 audio_param.value.i = spec->freq;
170 if( alSetParams(AL_DEFAULT_OUTPUT, &audio_param, 1) < 0 ) {
171 SDL_SetError("alSetParams failed");
172 return(-1);
173 }
174
175 /* Open the audio port with the requested frequency */
176 audio_port = NULL;
177 audio_config = alNewConfig();
178 if ( audio_config &&
179 (alSetSampFmt(audio_config, AL_SAMPFMT_TWOSCOMP) >= 0) &&
180 (alSetWidth(audio_config, width) >= 0) &&
181 (alSetQueueSize(audio_config, spec->samples*2) >= 0) &&
182 (alSetChannels(audio_config, spec->channels) >= 0) ) {
183 audio_port = ALopenport("SDL audio", "w", audio_config);
184 }
185 alFreeConfig(audio_config);
186 if( audio_port == NULL ) {
187 SDL_SetError("Unable to open audio port");
188 return(-1);
189 }
190
191 /* Allocate mixing buffer */
192 mixbuf = (Uint8 *)SDL_AllocAudioMem(spec->size);
193 if ( mixbuf == NULL ) {
194 SDL_OutOfMemory();
195 return(-1);
196 }
197 memset(mixbuf, spec->silence, spec->size);
198
199 /* We're ready to rock and roll. :-) */
200 return(0);
201 }