1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2012 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 written by Ryan C. Gordon (icculus@icculus.org)
23 */
24 #include "SDL_config.h"
25
26 /* Output raw audio data to a file. */
27
28 #if HAVE_STDIO_H
29 #include <stdio.h>
30 #endif
31
32 #include "SDL_rwops.h"
33 #include "SDL_timer.h"
34 #include "SDL_audio.h"
35 #include "../SDL_audiomem.h"
36 #include "../SDL_audio_c.h"
37 #include "../SDL_audiodev_c.h"
38 #include "SDL_diskaudio.h"
39
40 /* The tag name used by DISK audio */
41 #define DISKAUD_DRIVER_NAME "disk"
42
43 /* environment variables and defaults. */
44 #define DISKENVR_OUTFILE "SDL_DISKAUDIOFILE"
45 #define DISKDEFAULT_OUTFILE "sdlaudio.raw"
46 #define DISKENVR_WRITEDELAY "SDL_DISKAUDIODELAY"
47 #define DISKDEFAULT_WRITEDELAY 150
48
49 /* Audio driver functions */
50 static int DISKAUD_OpenAudio(_THIS, SDL_AudioSpec *spec);
51 static void DISKAUD_WaitAudio(_THIS);
52 static void DISKAUD_PlayAudio(_THIS);
53 static Uint8 *DISKAUD_GetAudioBuf(_THIS);
54 static void DISKAUD_CloseAudio(_THIS);
55
DISKAUD_GetOutputFilename(void)56 static const char *DISKAUD_GetOutputFilename(void)
57 {
58 const char *envr = SDL_getenv(DISKENVR_OUTFILE);
59 return((envr != NULL) ? envr : DISKDEFAULT_OUTFILE);
60 }
61
62 /* Audio driver bootstrap functions */
DISKAUD_Available(void)63 static int DISKAUD_Available(void)
64 {
65 const char *envr = SDL_getenv("SDL_AUDIODRIVER");
66 if (envr && (SDL_strcmp(envr, DISKAUD_DRIVER_NAME) == 0)) {
67 return(1);
68 }
69 return(0);
70 }
71
DISKAUD_DeleteDevice(SDL_AudioDevice * device)72 static void DISKAUD_DeleteDevice(SDL_AudioDevice *device)
73 {
74 SDL_free(device->hidden);
75 SDL_free(device);
76 }
77
DISKAUD_CreateDevice(int devindex)78 static SDL_AudioDevice *DISKAUD_CreateDevice(int devindex)
79 {
80 SDL_AudioDevice *this;
81 const char *envr;
82
83 /* Initialize all variables that we clean on shutdown */
84 this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
85 if ( this ) {
86 SDL_memset(this, 0, (sizeof *this));
87 this->hidden = (struct SDL_PrivateAudioData *)
88 SDL_malloc((sizeof *this->hidden));
89 }
90 if ( (this == NULL) || (this->hidden == NULL) ) {
91 SDL_OutOfMemory();
92 if ( this ) {
93 SDL_free(this);
94 }
95 return(0);
96 }
97 SDL_memset(this->hidden, 0, (sizeof *this->hidden));
98
99 envr = SDL_getenv(DISKENVR_WRITEDELAY);
100 this->hidden->write_delay = (envr) ? SDL_atoi(envr) : DISKDEFAULT_WRITEDELAY;
101
102 /* Set the function pointers */
103 this->OpenAudio = DISKAUD_OpenAudio;
104 this->WaitAudio = DISKAUD_WaitAudio;
105 this->PlayAudio = DISKAUD_PlayAudio;
106 this->GetAudioBuf = DISKAUD_GetAudioBuf;
107 this->CloseAudio = DISKAUD_CloseAudio;
108
109 this->free = DISKAUD_DeleteDevice;
110
111 return this;
112 }
113
114 AudioBootStrap DISKAUD_bootstrap = {
115 DISKAUD_DRIVER_NAME, "direct-to-disk audio",
116 DISKAUD_Available, DISKAUD_CreateDevice
117 };
118
119 /* This function waits until it is possible to write a full sound buffer */
DISKAUD_WaitAudio(_THIS)120 static void DISKAUD_WaitAudio(_THIS)
121 {
122 SDL_Delay(this->hidden->write_delay);
123 }
124
DISKAUD_PlayAudio(_THIS)125 static void DISKAUD_PlayAudio(_THIS)
126 {
127 int written;
128
129 /* Write the audio data */
130 written = SDL_RWwrite(this->hidden->output,
131 this->hidden->mixbuf, 1,
132 this->hidden->mixlen);
133
134 /* If we couldn't write, assume fatal error for now */
135 if ( (Uint32)written != this->hidden->mixlen ) {
136 this->enabled = 0;
137 }
138 #ifdef DEBUG_AUDIO
139 fprintf(stderr, "Wrote %d bytes of audio data\n", written);
140 #endif
141 }
142
DISKAUD_GetAudioBuf(_THIS)143 static Uint8 *DISKAUD_GetAudioBuf(_THIS)
144 {
145 return(this->hidden->mixbuf);
146 }
147
DISKAUD_CloseAudio(_THIS)148 static void DISKAUD_CloseAudio(_THIS)
149 {
150 if ( this->hidden->mixbuf != NULL ) {
151 SDL_FreeAudioMem(this->hidden->mixbuf);
152 this->hidden->mixbuf = NULL;
153 }
154 if ( this->hidden->output != NULL ) {
155 SDL_RWclose(this->hidden->output);
156 this->hidden->output = NULL;
157 }
158 }
159
DISKAUD_OpenAudio(_THIS,SDL_AudioSpec * spec)160 static int DISKAUD_OpenAudio(_THIS, SDL_AudioSpec *spec)
161 {
162 const char *fname = DISKAUD_GetOutputFilename();
163
164 /* Open the audio device */
165 this->hidden->output = SDL_RWFromFile(fname, "wb");
166 if ( this->hidden->output == NULL ) {
167 return(-1);
168 }
169
170 #if HAVE_STDIO_H
171 fprintf(stderr, "WARNING: You are using the SDL disk writer"
172 " audio driver!\n Writing to file [%s].\n", fname);
173 #endif
174
175 /* Allocate mixing buffer */
176 this->hidden->mixlen = spec->size;
177 this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
178 if ( this->hidden->mixbuf == NULL ) {
179 return(-1);
180 }
181 SDL_memset(this->hidden->mixbuf, spec->silence, spec->size);
182
183 /* We're ready to rock and roll. :-) */
184 return(0);
185 }
186
187