Mercurial > sdl-ios-xcode

comparison src/audio/dummy/SDL_dummyaudio.c @ 1532:30f189cdd82b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Implemented dummy audio driver. Fixes Bugzilla #161.
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 14 Mar 2006 08:53:33 +0000
parents
children 38c1eb6b0083
comparison
equal deleted inserted replaced
1531:543ffd71ab6d 1532:30f189cdd82b
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2006 Sam Lantinga
4
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 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 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with this library; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19 Sam Lantinga
20 slouken@libsdl.org
21
22 This file hacked^H^H^H^H^H^Hwritten by Ryan C. Gordon
23 (icculus@icculus.org)
24 */
25 #include "SDL_config.h"
26
27 /* Output raw audio data to a file. */
28
29 #if HAVE_STDIO_H
30 #include <stdio.h>
31 #endif
32
33 #include "SDL_rwops.h"
34 #include "SDL_timer.h"
35 #include "SDL_audio.h"
36 #include "../SDL_audiomem.h"
37 #include "../SDL_audio_c.h"
38 #include "../SDL_audiodev_c.h"
39 #include "SDL_dummyaudio.h"
40
41 /* The tag name used by DUMMY audio */
42 #define DUMMYAUD_DRIVER_NAME "dummy"
43
44 /* environment variables and defaults. */
45 #define DUMMYENVR_WRITEDELAY "SDL_DUMMYAUDIODELAY"
46 #define DUMMYDEFAULT_WRITEDELAY 150
47
48 /* Audio driver functions */
49 static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec);
50 static void DUMMYAUD_WaitAudio(_THIS);
51 static void DUMMYAUD_PlayAudio(_THIS);
52 static Uint8 *DUMMYAUD_GetAudioBuf(_THIS);
53 static void DUMMYAUD_CloseAudio(_THIS);
54
55 /* Audio driver bootstrap functions */
56 static int DUMMYAUD_Available(void)
57 {
58 const char *envr = SDL_getenv("SDL_AUDIODRIVER");
59 if (envr && (SDL_strcmp(envr, DUMMYAUD_DRIVER_NAME) == 0)) {
60 return(1);
61 }
62 return(0);
63 }
64
65 static void DUMMYAUD_DeleteDevice(SDL_AudioDevice *device)
66 {
67 SDL_free(device->hidden);
68 SDL_free(device);
69 }
70
71 static SDL_AudioDevice *DUMMYAUD_CreateDevice(int devindex)
72 {
73 SDL_AudioDevice *this;
74 const char *envr;
75
76 /* Initialize all variables that we clean on shutdown */
77 this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
78 if ( this ) {
79 SDL_memset(this, 0, (sizeof *this));
80 this->hidden = (struct SDL_PrivateAudioData *)
81 SDL_malloc((sizeof *this->hidden));
82 }
83 if ( (this == NULL) || (this->hidden == NULL) ) {
84 SDL_OutOfMemory();
85 if ( this ) {
86 SDL_free(this);
87 }
88 return(0);
89 }
90 SDL_memset(this->hidden, 0, (sizeof *this->hidden));
91
92 envr = SDL_getenv(DUMMYENVR_WRITEDELAY);
93 this->hidden->write_delay = (envr) ? SDL_atoi(envr) : DUMMYDEFAULT_WRITEDELAY;
94
95 /* Set the function pointers */
96 this->OpenAudio = DUMMYAUD_OpenAudio;
97 this->WaitAudio = DUMMYAUD_WaitAudio;
98 this->PlayAudio = DUMMYAUD_PlayAudio;
99 this->GetAudioBuf = DUMMYAUD_GetAudioBuf;
100 this->CloseAudio = DUMMYAUD_CloseAudio;
101
102 this->free = DUMMYAUD_DeleteDevice;
103
104 return this;
105 }
106
107 AudioBootStrap DUMMYAUD_bootstrap = {
108 DUMMYAUD_DRIVER_NAME, "SDL dummy audio driver",
109 DUMMYAUD_Available, DUMMYAUD_CreateDevice
110 };
111
112 /* This function waits until it is possible to write a full sound buffer */
113 static void DUMMYAUD_WaitAudio(_THIS)
114 {
115 SDL_Delay(this->hidden->write_delay);
116 }
117
118 static void DUMMYAUD_PlayAudio(_THIS)
119 {
120 /* no-op...this is a null driver. */
121 }
122
123 static Uint8 *DUMMYAUD_GetAudioBuf(_THIS)
124 {
125 return(this->hidden->mixbuf);
126 }
127
128 static void DUMMYAUD_CloseAudio(_THIS)
129 {
130 if ( this->hidden->mixbuf != NULL ) {
131 SDL_FreeAudioMem(this->hidden->mixbuf);
132 this->hidden->mixbuf = NULL;
133 }
134 }
135
136 static int DUMMYAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)
137 {
138 #if HAVE_STDIO_H
139 fprintf(stderr, "\nWARNING: You are using the SDL dummy audio driver!"
140 " No sound will be output!\n\n");
141 #endif
142
143 /* Allocate mixing buffer */
144 this->hidden->mixlen = spec->size;
145 this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
146 if ( this->hidden->mixbuf == NULL ) {
147 return(-1);
148 }
149 SDL_memset(this->hidden->mixbuf, spec->silence, spec->size);
150
151 /* We're ready to rock and roll. :-) */
152 return(0);
153 }
154