c/sampler/c/sdl-old.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Michal Turek - Woq                              *
   3  *   WOQ (zavinac) seznam.cz                                               *
   4  *                                                                         *
   5  *   Program ukazuje nahrani zvuku ve formatu .AU pomoci knihovny          *
   6  *   SDL_sound, jeho dekodovani a nasledne prehravani                      *
   7  *   (opet pro jednoduchost smycka). Zde je pouzit .AU, ale naprosto       *
   8  *   stejnym zpusobem lze pouzivat zvukove soubory jakychkoli jinych       *
   9  *   formatu (.MP3, .OGG atd.), staci jen zmenit jmeno souboru.            *
  10  *                                                                         *
  11  *   This program is free software; you can redistribute it and/or modify  *
  12  *   it under the terms of the GNU General Public License as published by  *
  13  *   the Free Software Foundation; either version 2 of the License, or     *
  14  *   (at your option) any later version.                                   *
  15  *                                                                         *
  16  *   This program is distributed in the hope that it will be useful,       *
  17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  19  *   GNU General Public License for more details.                          *
  20  *                                                                         *
  21  *   You should have received a copy of the GNU General Public License     *
  22  *   along with this program; if not, write to the                         *
  23  *   Free Software Foundation, Inc.,                                       *
  24  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  25  ***************************************************************************/
  26
  27 #include <stdio.h>
  28 #include <SDL/SDL.h>
  29 #include <SDL/SDL_sound.h>// Nezapomenout prilinkovat -lSDL_sound
  30
  31
  32 /*
  33  * Symbolicke konstanty
  34  */
  35
  36 #define SDL_SUBSYSTEMS SDL_INIT_AUDIO
  37
  38 /*
  39  * Funkcni prototypy
  40  */
  41
  42 void AudioCallback(void *unused, Uint8 *stream, int len);
  43 int Init();                                     // Inicializace
  44 void Destroy();                                 // Deinicializace
  45 int ProcessEvent();                             // Osetruje udalosti
  46 int  main(int argc, char *argv[]);              // Vstup do programu
  47
  48
  49 /*
  50  * Globalni promenne
  51  */
  52
  53
  54 Sound_Sample *g_sample;                         // Zvuk
  55 Uint32 g_pos;                                   // Pozice pri prehravani
  56
  57
  58 /*
  59  * Audio callback funkce, posila data do streamu
  60  */
  61
  62 void AudioCallback(void *unused, Uint8 *stream, int len)
  63 {
  64         // Ukazatel na cast, kde se ma zacit prehravat
  65         Uint8 *wave_ptr = (Uint8 *)g_sample->buffer + g_pos;
  66
  67         // Delka zvuku do konce
  68         int wave_left = g_sample->buffer_size - g_pos;
  69
  70         // Zbyvajici delka je mensi nez pozadovana
  71         // Cyklus, protoze cely zvuk muze byt kratsi
  72         while(wave_left <= len)
  73         {
  74                 // Posle data na zvukovou kartu
  75                 SDL_MixAudio(stream, wave_ptr, wave_left, SDL_MIX_MAXVOLUME);
  76
  77                 // Posune se o prave zapsana data
  78                 stream += wave_left;
  79                 len -= wave_left;
  80
  81                 // Od zacatku zvuku
  82                 wave_ptr = (Uint8 *)g_sample->buffer;
  83                 wave_left = g_sample->buffer_size;
  84                 g_pos = 0;
  85         }
  86
  87         // Je jistota, ze zbyvajici cast zvuku je delsi nez pozadovana
  88         SDL_MixAudio(stream, wave_ptr, len, SDL_MIX_MAXVOLUME);
  89         g_pos += len;
  90 }
  91
  92
  93 /*
  94  * Inicializacni funkce
  95  */
  96
  97 int Init()
  98 {
  99         // Inicializace SDL
 100         if(SDL_Init(SDL_SUBSYSTEMS) == -1)
 101         {
 102                 fprintf(stderr, "Unable to initialize SDL: %s\n",
 103                                 SDL_GetError());
 104                 return 0;
 105         }
 106
 107         // Inicializace SDL_sound
 108         if(Sound_Init() == 0)
 109         {
 110                 fprintf(stderr, "Unable to initialize SDL_sound: %s\n",
 111                                 Sound_GetError());
 112                 return 0;
 113         }
 114
 115         // Vypise verzi SDL_sound
 116         Sound_Version compiled;
 117         Sound_Version linked;
 118         SOUND_VERSION(&compiled);
 119         Sound_GetLinkedVersion(&linked);
 120
 121         printf("\nVersion of compiled SDL_sound: %d.%d.%d\n",
 122                 compiled.major, compiled.minor, compiled.patch);
 123         printf("Version of linked SDL_sound: %d.%d.%d\n\n",
 124                 linked.major, linked.minor, linked.patch);
 125
 126         // Vypise dostupne audio formaty
 127         const Sound_DecoderInfo **dec_info = Sound_AvailableDecoders();
 128
 129         printf("Supported sound formats:\n");
 130         int i;
 131         for(i = 0; dec_info[i] != NULL; i++)
 132         {
 133                 printf("%s\t- %s\n",
 134                         *dec_info[i]->extensions, dec_info[i]->description);
 135         }
 136         printf("\n");
 137
 138         // Nastaveni audia
 139         SDL_AudioSpec desired, obtained;
 140         desired.freq = 22050;// 16-bit. stereo na 22 kHz
 141         desired.format = AUDIO_S16;
 142         desired.channels = 2;
 143         desired.samples = 512;// Vhodne pro hry
 144         desired.callback = AudioCallback;
 145         desired.userdata = NULL;
 146
 147         // Otevre audio zarizeni
 148         if(SDL_OpenAudio(&desired, &obtained) == -1)
 149         {
 150                 fprintf(stderr, "Unable to open audio: %s\n", SDL_GetError());
 151                 return 0;
 152         }
 153
 154         // Loading audia a dekodovani (vse najednou)
 155         Sound_AudioInfo info;
 156         info.channels = obtained.channels;
 157         info.format = obtained.format;
 158         info.rate = obtained.freq;
 159
 160         g_sample = Sound_NewSampleFromFile("bd.wav", &info, 512);
 161         if(g_sample == NULL)
 162         {
 163                 fprintf(stderr, "Unable to load sound: %s\n", Sound_GetError());
 164                 return 0;
 165         }
 166
 167         // Dekoduje cely zvuk najednou
 168         Sound_DecodeAll(g_sample);
 169         if(g_sample->flags & SOUND_SAMPLEFLAG_ERROR)
 170         {
 171                 fprintf(stderr, "Unable to decode sound: %s\n",
 172                                 Sound_GetError());
 173                 return 0;
 174         }
 175
 176         // Zacne prehravat
 177         SDL_PauseAudio(0);
 178
 179         return 1;
 180 }
 181
 182
 183 /*
 184  * Deinicializacni funkce
 185  */
 186
 187 void Destroy()
 188 {
 189         Sound_FreeSample(g_sample);     // Uvolni zvuk
 190         Sound_Quit();                   // Ukonci SDL_sound
 191         SDL_CloseAudio();               // Zavre audio zarizeni
 192         SDL_Quit();                     // Deinicializuje SDL
 193 }
 194
 195
 196 /*
 197  * Osetreni udalosti
 198  */
 199
 200 int ProcessEvent()
 201 {
 202         SDL_Event event;
 203
 204         while(SDL_WaitEvent(&event))
 205         {
 206                 switch(event.type)
 207                 {
 208                 case SDL_KEYDOWN:
 209                         switch(event.key.keysym.sym)
 210                         {
 211                         case SDLK_ESCAPE:
 212                                 return 0;
 213                                 break;
 214
 215                         default:
 216                                 break;
 217                         }
 218                         break;
 219
 220                 case SDL_QUIT:
 221                         return 0;
 222                         break;
 223
 224                 default:
 225                         break;
 226                 }
 227         }
 228
 229         return 1;
 230 }
 231
 232
 233 /*
 234  * Vstup do programu
 235  */
 236
 237 int main(int argc, char *argv[])
 238 {
 239         printf("\nPress ESC key to quit.\n");
 240
 241         // Inicializace
 242         if(!Init())
 243         {
 244                 Destroy();
 245                 return 1;
 246         }
 247
 248         // Hlavni smycka programu
 249         int done = 0;
 250         while(!done)
 251         {
 252                 done = !ProcessEvent();
 253         }
 254
 255         // Deinicializace a konec
 256         Destroy();
 257         return 0;
 258 }
 259