| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 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 | |
| 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 */ |
| 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 | |
| 72 | static void DISKAUD_DeleteDevice(SDL_AudioDevice *device) |
| 73 | { |
| 74 | SDL_free(device->hidden); |
| 75 | SDL_free(device); |
| 76 | } |
| 77 | |
| 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 */ |
| 120 | static void DISKAUD_WaitAudio(_THIS) |
| 121 | { |
| 122 | SDL_Delay(this->hidden->write_delay); |
| 123 | } |
| 124 | |
| 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 | |
| 143 | static Uint8 *DISKAUD_GetAudioBuf(_THIS) |
| 144 | { |
| 145 | return(this->hidden->mixbuf); |
| 146 | } |
| 147 | |
| 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 | |
| 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 | |