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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
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24
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25 /* Allow access to a raw mixing buffer */
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26
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27 #include <stdlib.h>
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28 #include <stdio.h>
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29 #include <string.h>
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30 #include <errno.h>
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31 #include <unistd.h>
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32 #include <fcntl.h>
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33 #include <signal.h>
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34 #include <sys/types.h>
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35 #include <sys/time.h>
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36 #include <sched.h>
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37 #include <sys/asoundlib.h>
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38
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39 #include "SDL_audio.h"
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40 #include "SDL_error.h"
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41 #include "SDL_audiomem.h"
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42 #include "SDL_audio_c.h"
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43 #include "SDL_timer.h"
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44 #include "SDL_nto_audio.h"
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45
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46 /* The tag name used by NTO audio */
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47 #define DRIVER_NAME "nto"
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48
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49 /* default card and device numbers as listed in dev/snd */
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50 static int card_no = 0;
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51 static int device_no = 0;
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52
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53 /* default channel communication parameters */
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54 #define DEFAULT_CPARAMS_RATE 22050
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55 #define DEFAULT_CPARAMS_VOICES 1
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56 #define DEFAULT_CPARAMS_FRAG_SIZE 4096 //was 512
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57 #define DEFAULT_CPARAMS_FRAGS_MIN 1
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58 #define DEFAULT_CPARAMS_FRAGS_MAX -1
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59
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60 /* Open the audio device for playback, and don't block if busy */
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61 #define OPEN_FLAGS SND_PCM_OPEN_PLAYBACK
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62
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63 /* Audio driver functions */
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64 static int NTO_OpenAudio(_THIS, SDL_AudioSpec *spec);
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65 static void NTO_WaitAudio(_THIS);
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66 static void NTO_PlayAudio(_THIS);
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67 static Uint8 *NTO_GetAudioBuf(_THIS);
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68 static void NTO_CloseAudio(_THIS);
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69
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70 static snd_pcm_channel_status_t cstatus;
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71 static snd_pcm_channel_params_t cparams;
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72 static snd_pcm_channel_setup_t csetup;
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73
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74 /* PCM transfer channel parameters initialize function */
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75 static void init_pcm_cparams(snd_pcm_channel_params_t* cparams)
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76 {
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77 memset(cparams,0,sizeof(snd_pcm_channel_params_t));
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78
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79 cparams->channel = SND_PCM_CHANNEL_PLAYBACK;
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80 cparams->mode = SND_PCM_MODE_BLOCK;
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81 cparams->start_mode = SND_PCM_START_DATA; //_FULL
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82 cparams->stop_mode = SND_PCM_STOP_STOP;
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83 cparams->format.format = SND_PCM_SFMT_S16_LE;
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84 cparams->format.interleave = 1;
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85 cparams->format.rate = DEFAULT_CPARAMS_RATE;
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86 cparams->format.voices = DEFAULT_CPARAMS_VOICES;
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87 cparams->buf.block.frag_size = DEFAULT_CPARAMS_FRAG_SIZE;
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88 cparams->buf.block.frags_min = DEFAULT_CPARAMS_FRAGS_MIN;
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89 cparams->buf.block.frags_max = DEFAULT_CPARAMS_FRAGS_MAX;
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90 }
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91
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92 /* Audio driver bootstrap functions */
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93
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94 static int Audio_Available(void)
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95 /*
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96 See if we can open a nonblocking channel.
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97 Return value '1' means we can.
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98 Return value '0' means we cannot.
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99 */
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100 {
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101 int available;
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102 int rval;
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103 snd_pcm_t *handle;
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104
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105 available = 0;
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106 handle = NULL;
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107
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108 //JB modified to take advantage of software mixer
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109 rval = snd_pcm_open_preferred(&handle, &card_no, &device_no, OPEN_FLAGS);
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110
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111 if (rval >= 0)
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112 {
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113 available = 1;
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114
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115 if ((rval = snd_pcm_close(handle)) < 0)
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116 {
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117 SDL_SetError("snd_pcm_close failed: %s\n",snd_strerror(rval));
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118 available = 0;
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119 }
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120 }
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121 else
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122 {
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123
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124 SDL_SetError("snd_pcm_open failed: %s\n", snd_strerror(rval));
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125 }
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126
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127 #ifdef DEBUG_AUDIO
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128 fprintf(stderr,"AudioAvailable rtns %d\n", available);
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129 #endif
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130 return(available);
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131 }
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132
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133 static void Audio_DeleteDevice(SDL_AudioDevice *device)
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134 {
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135 #ifdef DEBUG_AUDIO
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136 fprintf(stderr,"Audio_DeleteDevice\n");
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137 #endif
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138
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139
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140 free(device->hidden);
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141 free(device);
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142 }
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143
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144 static SDL_AudioDevice *Audio_CreateDevice(int devindex)
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145 {
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146 SDL_AudioDevice *this;
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147 #ifdef DEBUG_AUDIO
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148 fprintf(stderr,"Audio_CreateDevice\n");
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149 #endif
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150 /* Initialize all variables that we clean on shutdown */
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151 this = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
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152 if ( this ) {
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153 memset(this, 0, (sizeof *this));
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154 this->hidden = (struct SDL_PrivateAudioData *)
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155 malloc((sizeof *this->hidden));
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156 }
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157 if ( (this == NULL) || (this->hidden == NULL) ) {
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158 SDL_OutOfMemory();
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159 if ( this ) {
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160 free(this);
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161 }
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162 return(0);
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163 }
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164 memset(this->hidden, 0, (sizeof *this->hidden));
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165 audio_handle = NULL;
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166
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167 /* Set the function pointers */
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168 this->OpenAudio = NTO_OpenAudio;
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169 this->WaitAudio = NTO_WaitAudio;
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170 this->PlayAudio = NTO_PlayAudio;
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171 this->GetAudioBuf = NTO_GetAudioBuf;
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172 this->CloseAudio = NTO_CloseAudio;
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173
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174 this->free = Audio_DeleteDevice;
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175
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176 return this;
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177 }
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178
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179 /* Don't change the name from "ALSA_bootstrap" - that's how it's called */
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180 AudioBootStrap ALSA_bootstrap = {
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181 DRIVER_NAME, "Neutrino PCM audio",
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182 Audio_Available, Audio_CreateDevice
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183 };
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184
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185 /* This function waits until it is possible to write a full sound buffer */
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186 static void NTO_WaitAudio(_THIS)
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187 {
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188 int rval;
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189 int totalbytes,roomavail;
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190 /*we consider a full sound buffer to be of size pcm_len bytes */
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191
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192 #ifdef DEBUG_AUDIO
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193 fprintf(stderr,"NTO_WaitAudio\n");
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194 #endif
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195
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196 while(1)
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197 {
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198 memset(&cstatus, 0, sizeof(cstatus));
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199 if( (rval = snd_pcm_plugin_status(audio_handle, &cstatus)) < 0 )
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200 {
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201 SDL_SetError("snd_pcm_plugin_status failed: %s\n", snd_strerror(rval));
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202 return;
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203 }
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204
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205 totalbytes = csetup.buf.block.frag_size *csetup.buf.block.frags;
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206 roomavail = totalbytes - cstatus.count;
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207
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208 #ifdef DEBUG_AUDIO
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209 fprintf(stderr,"NTO_WaitAudio roomavail %d pcm_len %d\n",roomavail,pcm_len);
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210 #endif
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211
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212 if ((roomavail >= pcm_len) || (roomavail < 0))
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213 return;
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214
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215 SDL_Delay(10);
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216 }
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217
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218 }
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219
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220
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221
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222 static void NTO_PlayAudio(_THIS)
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223 {
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224 int written, rval;
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225 int towrite;
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226
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227 #ifdef DEBUG_AUDIO
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228 fprintf(stderr, "NTO_PlayAudio\n");
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229 #endif
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230
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231 if( !this->enabled)
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232 return;
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233
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234 towrite = pcm_len;
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235
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236
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237 /* Write the audio data, checking for EAGAIN (buffer full) and underrun */
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238 do {
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239 written = snd_pcm_plugin_write(audio_handle, pcm_buf, towrite);
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240 #ifdef DEBUG_AUDIO
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241 fprintf(stderr, "NTO_PlayAudio: written = %d towrite = %d\n",written,towrite);
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242 #endif
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243 if (written != towrite)
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244 {
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245 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
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246 {
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247 SDL_Delay(1); /* Let a little CPU time go by and try to write again */
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248 #ifdef DEBUG_AUDIO
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249 fprintf(stderr, "errno == EAGAIN written %d\n", written);
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250 towrite -= written; //we wrote some data
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251 #endif
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252 continue;
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253 }
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254 else if((errno == EINVAL) || (errno == EIO))
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255 {
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256 #ifdef DEBUG_AUDIO
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257 if(errno == EIO)
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258 fprintf(stderr,"snd_pcm_plugin_write failed EIO: %s\n", snd_strerror(written));
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259 if(errno == EINVAL)
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260 fprintf(stderr,"snd_pcm_plugin_write failed EINVAL: %s\n", snd_strerror(written));
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261
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262 #endif
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263
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264 memset(&cstatus, 0, sizeof(cstatus));
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265 if( (rval = snd_pcm_plugin_status(audio_handle, &cstatus)) < 0 )
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266 {
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267 #ifdef DEBUG_AUDIO
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268 fprintf(stderr, "snd_pcm_plugin_status failed %s\n",snd_strerror(rval));
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269 #endif
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270 SDL_SetError("snd_pcm_plugin_status failed: %s\n", snd_strerror(rval));
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271 return;
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272 }
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273
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274 if ( (cstatus.status == SND_PCM_STATUS_UNDERRUN) ||
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275 (cstatus.status == SND_PCM_STATUS_READY) )
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276 {
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277 #ifdef DEBUG_AUDIO
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278 fprintf(stderr, "buffer underrun\n");
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279 #endif
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280 if ( (rval = snd_pcm_plugin_prepare (audio_handle,SND_PCM_CHANNEL_PLAYBACK)) < 0 )
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281 {
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282 #ifdef DEBUG_AUDIO
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283 fprintf(stderr, "NTO_PlayAudio: prepare failed %s\n",snd_strerror(rval));
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284 #endif
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285 SDL_SetError("snd_pcm_plugin_prepare failed: %s\n",snd_strerror(rval) );
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286 return;
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287 }
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288
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289 }
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290 continue;
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291 }
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292 else
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293 {
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294 #ifdef DEBUG_AUDIO
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295 fprintf(stderr, "NTO_PlayAudio: snd_pcm_plugin_write failed unknown errno %d %s\n",errno, snd_strerror(rval));
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296 #endif
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297 return;
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298
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299 }
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300
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301 }
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302 else
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303 {
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304 towrite -= written; //we wrote all remaining data
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305 }
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306 } while ( (towrite > 0) && (this->enabled) );
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307
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308 /* If we couldn't write, assume fatal error for now */
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309 if ( towrite != 0 ) {
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310 this->enabled = 0;
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311 }
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312 return;
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313 }
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314
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315 static Uint8 *NTO_GetAudioBuf(_THIS)
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316 {
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317 #ifdef DEBUG_AUDIO
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318 fprintf(stderr, "NTO_GetAudioBuf: pcm_buf %X\n",(Uint8 *)pcm_buf);
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319 #endif
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320 return(pcm_buf);
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321 }
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322
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323 static void NTO_CloseAudio(_THIS)
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324 {
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325 int rval;
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326
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327 #ifdef DEBUG_AUDIO
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328 fprintf(stderr, "NTO_CloseAudio\n");
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329 #endif
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330
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331 this->enabled = 0;
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332
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333 if ( audio_handle != NULL ) {
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334 if ((rval = snd_pcm_plugin_flush(audio_handle,SND_PCM_CHANNEL_PLAYBACK)) < 0)
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335 {
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336 SDL_SetError("snd_pcm_plugin_flush failed: %s\n",snd_strerror(rval));
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337 return;
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338 }
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339 if ((rval = snd_pcm_close(audio_handle)) < 0)
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340 {
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341 SDL_SetError("snd_pcm_close failed: %s\n",snd_strerror(rval));
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342 return;
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343 }
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344 audio_handle = NULL;
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345 }
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346 }
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347
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348 static int NTO_OpenAudio(_THIS, SDL_AudioSpec *spec)
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349 {
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350 int rval;
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351 int format;
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352 Uint16 test_format;
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353 int twidth;
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354 int found;
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355
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356 #ifdef DEBUG_AUDIO
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357 fprintf(stderr, "NTO_OpenAudio\n");
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358 #endif
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359
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360 audio_handle = NULL;
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361 this->enabled = 0;
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362
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363 if ( pcm_buf != NULL ) {
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364 free((Uint8 *)pcm_buf);
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365 pcm_buf = NULL;
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366 }
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367
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368 /* initialize channel transfer parameters to default */
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369 init_pcm_cparams(&cparams);
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370
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371 /* Open the audio device */
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372
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373 rval = snd_pcm_open_preferred(&audio_handle, &card_no, &device_no, OPEN_FLAGS);
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374 if ( rval < 0 ) {
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375 SDL_SetError("snd_pcm_open failed: %s\n", snd_strerror(rval));
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376 return(-1);
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377 }
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378
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379 /* set to nonblocking mode */
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380 if ((rval = snd_pcm_nonblock_mode(audio_handle, 1))<0) //I assume 1 means on
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381 {
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382 SDL_SetError("snd_pcm_nonblock_mode failed: %s\n", snd_strerror(rval));
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383 return(-1);
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384 }
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385
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386 /* enable count status parameter */
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387 if ((rval = snd_plugin_set_disable(audio_handle, PLUGIN_DISABLE_MMAP))<0)
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388 {
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389 SDL_SetError("snd_plugin_set_disable failed: %s\n", snd_strerror(rval));
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390 return(-1);
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391 }
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392
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393
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394 /* Try for a closest match on audio format */
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395 format = 0;
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396 found = 0; // can't use format as SND_PCM_SFMT_U8 = 0 in nto
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397 for ( test_format = SDL_FirstAudioFormat(spec->format); !found ; )
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398
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399 {
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400 #ifdef DEBUG_AUDIO
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401 fprintf(stderr, "Trying format 0x%4.4x spec->samples %d\n", test_format,spec->samples);
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402 #endif
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403 /* if match found set format to equivalent ALSA format */
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404 switch ( test_format ) {
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405 case AUDIO_U8:
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406 format = SND_PCM_SFMT_U8;
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407 cparams.buf.block.frag_size = spec->samples * spec->channels;
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408 found = 1;
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409 break;
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410 case AUDIO_S8:
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411 format = SND_PCM_SFMT_S8;
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412 cparams.buf.block.frag_size = spec->samples * spec->channels;
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413 found = 1;
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414 break;
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415 case AUDIO_S16LSB:
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416 format = SND_PCM_SFMT_S16_LE;
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417 cparams.buf.block.frag_size = spec->samples*2 * spec->channels;
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418 found = 1;
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419 break;
|
|
|
420 case AUDIO_S16MSB:
|
|
|
421 format = SND_PCM_SFMT_S16_BE;
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|
|
422 cparams.buf.block.frag_size = spec->samples*2 * spec->channels;
|
|
|
423 found = 1;
|
|
|
424 break;
|
|
|
425 case AUDIO_U16LSB:
|
|
|
426 format = SND_PCM_SFMT_U16_LE;
|
|
|
427 cparams.buf.block.frag_size = spec->samples*2 * spec->channels;
|
|
|
428 found = 1;
|
|
|
429 break;
|
|
|
430 case AUDIO_U16MSB:
|
|
|
431 format = SND_PCM_SFMT_U16_BE;
|
|
|
432 cparams.buf.block.frag_size = spec->samples*2 * spec->channels;
|
|
|
433 found = 1;
|
|
|
434 break;
|
|
|
435 default:
|
|
|
436 break;
|
|
|
437 }
|
|
|
438 if ( ! found ) {
|
|
|
439 test_format = SDL_NextAudioFormat();
|
|
|
440 }
|
|
|
441 }
|
|
|
442
|
|
|
443 /* assumes test_format not 0 on success */
|
|
|
444 if ( test_format == 0 ) {
|
|
|
445 SDL_SetError("Couldn't find any hardware audio formats");
|
|
|
446 return(-1);
|
|
|
447 }
|
|
|
448
|
|
|
449 spec->format = test_format;
|
|
|
450
|
|
|
451 /* Set the audio format */
|
|
|
452 cparams.format.format = format;
|
|
|
453
|
|
|
454 /* Set mono or stereo audio (currently only two channels supported) */
|
|
|
455 cparams.format.voices = spec->channels;
|
|
|
456
|
|
|
457 #ifdef DEBUG_AUDIO
|
|
|
458 fprintf(stderr,"intializing channels %d\n", cparams.format.voices);
|
|
|
459 #endif
|
|
|
460
|
|
|
461
|
|
|
462 /* Set rate */
|
|
|
463 cparams.format.rate = spec->freq ;
|
|
|
464
|
|
|
465 /* Setup the transfer parameters according to cparams */
|
|
|
466 rval = snd_pcm_plugin_params(audio_handle, &cparams);
|
|
|
467 if (rval < 0) {
|
|
|
468 SDL_SetError("snd_pcm_channel_params failed: %s\n", snd_strerror (rval));
|
|
|
469 return(-1);
|
|
|
470 }
|
|
|
471
|
|
|
472 /* Make sure channel is setup right one last time */
|
|
|
473 memset( &csetup, 0, sizeof( csetup ) );
|
|
|
474 csetup.channel = SND_PCM_CHANNEL_PLAYBACK;
|
|
|
475 if ( snd_pcm_plugin_setup( audio_handle, &csetup ) < 0 )
|
|
|
476 {
|
|
|
477 SDL_SetError("Unable to setup playback channel\n" );
|
|
|
478 return(-1);
|
|
|
479 }
|
|
|
480 else
|
|
|
481 {
|
|
|
482 #ifdef DEBUG_AUDIO
|
|
|
483 fprintf(stderr,"requested format: %d\n",cparams.format.format);
|
|
|
484 fprintf(stderr,"requested frag size: %d\n",cparams.buf.block.frag_size);
|
|
|
485 fprintf(stderr,"requested max frags: %d\n\n",cparams.buf.block.frags_max);
|
|
|
486
|
|
|
487 fprintf(stderr,"real format: %d\n", csetup.format.format );
|
|
|
488 fprintf(stderr,"real frag size : %d\n", csetup.buf.block.frag_size );
|
|
|
489 fprintf(stderr,"real max frags : %d\n", csetup.buf.block.frags_max );
|
|
|
490 #endif // DEBUG_AUDIO
|
|
|
491 }
|
|
|
492
|
|
|
493
|
|
|
494 /* Allocate memory to the audio buffer and initialize with silence
|
|
|
495 (Note that buffer size must be a multiple of fragment size, so find closest multiple)
|
|
|
496 */
|
|
|
497
|
|
|
498 twidth = snd_pcm_format_width(format);
|
|
|
499 if (twidth < 0) {
|
|
|
500 printf("snd_pcm_format_width failed\n");
|
|
|
501 twidth = 0;
|
|
|
502 }
|
|
|
503
|
|
|
504 #ifdef DEBUG_AUDIO
|
|
|
505 fprintf(stderr,"format is %d bits wide\n",twidth);
|
|
|
506 #endif
|
|
|
507
|
|
|
508 pcm_len = spec->size ;
|
|
|
509
|
|
|
510
|
|
|
511 #ifdef DEBUG_AUDIO
|
|
|
512 fprintf(stderr,"pcm_len set to %d\n", pcm_len);
|
|
|
513 #endif
|
|
|
514
|
|
|
515 if (pcm_len == 0)
|
|
|
516 {
|
|
|
517 pcm_len = csetup.buf.block.frag_size;
|
|
|
518 }
|
|
|
519
|
|
|
520 pcm_buf = (Uint8*)malloc(pcm_len);
|
|
|
521 if (pcm_buf == NULL) {
|
|
|
522 SDL_SetError("pcm_buf malloc failed\n");
|
|
|
523 return(-1);
|
|
|
524 }
|
|
|
525 memset(pcm_buf,spec->silence,pcm_len);
|
|
|
526
|
|
|
527 #ifdef DEBUG_AUDIO
|
|
|
528 fprintf(stderr,"pcm_buf malloced and silenced.\n");
|
|
|
529 #endif
|
|
|
530
|
|
|
531 /* get the file descriptor */
|
|
|
532 if( (audio_fd = snd_pcm_file_descriptor(audio_handle, SND_PCM_CHANNEL_PLAYBACK)) < 0)
|
|
|
533 {
|
|
|
534 fprintf(stderr, "snd_pcm_file_descriptor failed with error code: %d\n", audio_fd);
|
|
|
535 }
|
|
|
536
|
|
|
537 /* Trigger audio playback */
|
|
|
538 rval = snd_pcm_plugin_prepare( audio_handle, SND_PCM_CHANNEL_PLAYBACK);
|
|
|
539 if (rval < 0) {
|
|
|
540 SDL_SetError("snd_pcm_plugin_prepare failed: %s\n", snd_strerror (rval));
|
|
|
541 return(-1);
|
|
|
542 }
|
|
|
543
|
|
|
544 this->enabled = 1;
|
|
|
545
|
|
|
546 /* Get the parent process id (we're the parent of the audio thread) */
|
|
|
547 parent = getpid();
|
|
|
548
|
|
|
549 /* We're ready to rock and roll. :-) */
|
|
|
550 return(0);
|
|
|
551 }
|
|
|
552
|
|
|
553
|
|
|
554
|
