0
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1 /*
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2 SDL - Simple DirectMedia Layer
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3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
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4
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5 This library is free software; you can redistribute it and/or
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6 modify it under the terms of the GNU Library General Public
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7 License as published by the Free Software Foundation; either
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8 version 2 of the License, or (at your option) any later version.
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9
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10 This library is distributed in the hope that it will be useful,
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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13 Library General Public License for more details.
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14
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15 You should have received a copy of the GNU Library General Public
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16 License along with this library; if not, write to the Free
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17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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18
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19 Sam Lantinga
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20 slouken@devolution.com
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21 */
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22
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23 #ifdef SAVE_RCSID
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24 static char rcsid =
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25 "@(#) $Id$";
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26 #endif
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27
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28 /* Allow access to an ESD network stream mixing buffer */
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29
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30 #ifdef ESD_SUPPORT
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31
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32 #include <stdlib.h>
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33 #include <stdio.h>
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34 #include <string.h>
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35 #include <errno.h>
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36 #include <signal.h>
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37 #include <unistd.h>
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38
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39 #include <esd.h>
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40
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41 #include "SDL_audio.h"
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42 #include "SDL_error.h"
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43 #include "SDL_audiomem.h"
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44 #include "SDL_audio_c.h"
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45 #include "SDL_timer.h"
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46 #include "SDL_audiodev_c.h"
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47 #include "SDL_esdaudio.h"
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48
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49 /* The tag name used by ESD audio */
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50 #define ESD_DRIVER_NAME "esd"
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51
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52 /* Audio driver functions */
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53 static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec);
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54 static void ESD_WaitAudio(_THIS);
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55 static void ESD_PlayAudio(_THIS);
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56 static Uint8 *ESD_GetAudioBuf(_THIS);
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57 static void ESD_CloseAudio(_THIS);
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58
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59 /* Audio driver bootstrap functions */
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60
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61 static int Audio_Available(void)
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62 {
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63 int connection;
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64 int available;
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65
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66 available = 0;
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67 connection = esd_open_sound(NULL);
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68 if ( connection >= 0 ) {
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69 available = 1;
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70 esd_close(connection);
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71 }
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72 return(available);
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73 }
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74
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75 static void Audio_DeleteDevice(SDL_AudioDevice *device)
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76 {
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77 free(device->hidden);
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78 free(device);
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79 }
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80
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81 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
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82 {
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83 SDL_AudioDevice *this;
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84
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85 /* Initialize all variables that we clean on shutdown */
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86 this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
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87 if ( this ) {
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88 memset(this, 0, (sizeof *this));
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89 this->hidden = (struct SDL_PrivateAudioData *)
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90 malloc((sizeof *this->hidden));
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91 }
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92 if ( (this == NULL) || (this->hidden == NULL) ) {
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93 SDL_OutOfMemory();
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94 if ( this ) {
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95 free(this);
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96 }
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97 return(0);
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98 }
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99 memset(this->hidden, 0, (sizeof *this->hidden));
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100 audio_fd = -1;
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101
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102 /* Set the function pointers */
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103 this->OpenAudio = ESD_OpenAudio;
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104 this->WaitAudio = ESD_WaitAudio;
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105 this->PlayAudio = ESD_PlayAudio;
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106 this->GetAudioBuf = ESD_GetAudioBuf;
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107 this->CloseAudio = ESD_CloseAudio;
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108
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109 this->free = Audio_DeleteDevice;
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110
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111 return this;
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112 }
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113
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114 AudioBootStrap ESD_bootstrap = {
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115 ESD_DRIVER_NAME, "Enlightened Sound Daemon",
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116 Audio_Available, Audio_CreateDevice
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117 };
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118
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119 /* This function waits until it is possible to write a full sound buffer */
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120 static void ESD_WaitAudio(_THIS)
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121 {
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122 Sint32 ticks;
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123
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124 /* Check to see if the thread-parent process is still alive */
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125 { static int cnt = 0;
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126 /* Note that this only works with thread implementations
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127 that use a different process id for each thread.
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128 */
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129 if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */
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130 if ( kill(parent, 0) < 0 ) {
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131 this->enabled = 0;
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132 }
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133 }
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134 }
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135
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136 /* Use timer for general audio synchronization */
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137 ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS;
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138 if ( ticks > 0 ) {
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139 SDL_Delay(ticks);
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140 }
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141 }
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142
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143 static void ESD_PlayAudio(_THIS)
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144 {
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145 int written;
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146
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147 /* Write the audio data, checking for EAGAIN on broken audio drivers */
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148 do {
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149 written = write(audio_fd, mixbuf, mixlen);
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150 if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) {
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151 SDL_Delay(1); /* Let a little CPU time go by */
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152 }
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153 } while ( (written < 0) &&
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154 ((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) );
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155
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156 /* Set the next write frame */
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157 next_frame += frame_ticks;
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158
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159 /* If we couldn't write, assume fatal error for now */
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160 if ( written < 0 ) {
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161 this->enabled = 0;
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162 }
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163 }
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164
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165 static Uint8 *ESD_GetAudioBuf(_THIS)
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166 {
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167 return(mixbuf);
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168 }
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169
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170 static void ESD_CloseAudio(_THIS)
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171 {
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172 if ( mixbuf != NULL ) {
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173 SDL_FreeAudioMem(mixbuf);
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174 mixbuf = NULL;
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175 }
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176 if ( audio_fd >= 0 ) {
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177 close(audio_fd);
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178 audio_fd = -1;
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179 }
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180 }
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181
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182 /* Try to get the name of the program */
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183 static char *get_progname(void)
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184 {
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185 char *progname = NULL;
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186 #ifdef linux
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187 FILE *fp;
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188 static char temp[BUFSIZ];
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189
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190 sprintf(temp, "/proc/%d/cmdline", getpid());
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191 fp = fopen(temp, "r");
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192 if ( fp != NULL ) {
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193 if ( fgets(temp, sizeof(temp)-1, fp) ) {
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194 progname = strrchr(temp, '/');
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195 if ( progname == NULL ) {
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196 progname = temp;
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197 } else {
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198 progname = progname+1;
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199 }
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200 }
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201 fclose(fp);
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202 }
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203 #endif
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204 return(progname);
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205 }
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206
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207 static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec)
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208 {
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209 esd_format_t format;
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210
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211 /* Convert audio spec to the ESD audio format */
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212 format = (ESD_STREAM | ESD_PLAY);
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213 switch ( spec->format & 0xFF ) {
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214 case 8:
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215 format |= ESD_BITS8;
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216 break;
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217 case 16:
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218 format |= ESD_BITS16;
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219 break;
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220 default:
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221 SDL_SetError("Unsupported ESD audio format");
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222 return(-1);
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223 }
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224 if ( spec->channels == 1 ) {
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225 format |= ESD_MONO;
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226 } else {
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227 format |= ESD_STEREO;
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228 }
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229 #if 0
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230 spec->samples = ESD_BUF_SIZE; /* Darn, no way to change this yet */
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231 #endif
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232
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233 /* Open a connection to the ESD audio server */
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234 audio_fd = esd_play_stream(format, spec->freq, NULL, get_progname());
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235 if ( audio_fd < 0 ) {
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236 SDL_SetError("Couldn't open ESD connection");
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237 return(-1);
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238 }
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239
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240 /* Calculate the final parameters for this audio specification */
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241 SDL_CalculateAudioSpec(spec);
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242 frame_ticks = (float)(spec->samples*1000)/spec->freq;
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243 next_frame = SDL_GetTicks()+frame_ticks;
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244
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245 /* Allocate mixing buffer */
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246 mixlen = spec->size;
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247 mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
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248 if ( mixbuf == NULL ) {
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249 return(-1);
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250 }
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251 memset(mixbuf, spec->silence, spec->size);
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252
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253 /* Get the parent process id (we're the parent of the audio thread) */
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254 parent = getpid();
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255
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256 /* We're ready to rock and roll. :-) */
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257 return(0);
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258 }
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259
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260 #endif /* ESD_SUPPORT */
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