kc3-lang/SDL/test/testmultiaudio.c

Branch : - branch - v2.28 - tag -

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  Commit

• Author : Philipp Wiesemann
  Date : 2014-12-10 21:10:55
  Hash : 45fa5642
  Message : Added comments in example program.

• test/testmultiaudio.c

• /*
    Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
  
    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.
  
    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely.
  */
  #include "SDL.h"
  
  #include <stdio.h> /* for fflush() and stdout */
  
  static SDL_AudioSpec spec;
  static Uint8 *sound = NULL;     /* Pointer to wave data */
  static Uint32 soundlen = 0;     /* Length of wave data */
  
  typedef struct
  {
      SDL_AudioDeviceID dev;
      int soundpos;
      volatile int done;
  } callback_data;
  
  void SDLCALL
  play_through_once(void *arg, Uint8 * stream, int len)
  {
      callback_data *cbd = (callback_data *) arg;
      Uint8 *waveptr = sound + cbd->soundpos;
      int waveleft = soundlen - cbd->soundpos;
      int cpy = len;
      if (cpy > waveleft)
          cpy = waveleft;
  
      SDL_memcpy(stream, waveptr, cpy);
      len -= cpy;
      cbd->soundpos += cpy;
      if (len > 0) {
          stream += cpy;
          SDL_memset(stream, spec.silence, len);
          cbd->done++;
      }
  }
  
  static void
  test_multi_audio(int devcount)
  {
      callback_data cbd[64];
      int keep_going = 1;
      int i;
      
  #ifdef __ANDROID__  
      SDL_Event event;
    
      /* Create a Window to get fully initialized event processing for testing pause on Android. */
      SDL_CreateWindow("testmultiaudio", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 320, 240, 0);
  #endif
  
      if (devcount > 64) {
          SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Too many devices (%d), clamping to 64...\n",
                  devcount);
          devcount = 64;
      }
  
      spec.callback = play_through_once;
  
      for (i = 0; i < devcount; i++) {
          const char *devname = SDL_GetAudioDeviceName(i, 0);
          SDL_Log("playing on device #%d: ('%s')...", i, devname);
          fflush(stdout);
  
          SDL_memset(&cbd[0], '\0', sizeof(callback_data));
          spec.userdata = &cbd[0];
          cbd[0].dev = SDL_OpenAudioDevice(devname, 0, &spec, NULL, 0);
          if (cbd[0].dev == 0) {
              SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Open device failed: %s\n", SDL_GetError());
          } else {
              SDL_PauseAudioDevice(cbd[0].dev, 0);
              while (!cbd[0].done) {
  #ifdef __ANDROID__                
                  /* Empty queue, some application events would prevent pause. */
                  while (SDL_PollEvent(&event)){}
  #endif                
                  SDL_Delay(100);
              }
              SDL_PauseAudioDevice(cbd[0].dev, 1);
              SDL_Log("done.\n");
              SDL_CloseAudioDevice(cbd[0].dev);
          }
      }
  
      SDL_memset(cbd, '\0', sizeof(cbd));
  
      SDL_Log("playing on all devices...\n");
      for (i = 0; i < devcount; i++) {
          const char *devname = SDL_GetAudioDeviceName(i, 0);
          spec.userdata = &cbd[i];
          cbd[i].dev = SDL_OpenAudioDevice(devname, 0, &spec, NULL, 0);
          if (cbd[i].dev == 0) {
              SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Open device %d failed: %s\n", i, SDL_GetError());
          }
      }
  
      for (i = 0; i < devcount; i++) {
          if (cbd[i].dev) {
              SDL_PauseAudioDevice(cbd[i].dev, 0);
          }
      }
  
      while (keep_going) {
          keep_going = 0;
          for (i = 0; i < devcount; i++) {
              if ((cbd[i].dev) && (!cbd[i].done)) {
                  keep_going = 1;
              }
          }
  #ifdef __ANDROID__        
          /* Empty queue, some application events would prevent pause. */
          while (SDL_PollEvent(&event)){}
  #endif        
          SDL_Delay(100);
      }
  
      for (i = 0; i < devcount; i++) {
          if (cbd[i].dev) {
              SDL_PauseAudioDevice(cbd[i].dev, 1);
              SDL_CloseAudioDevice(cbd[i].dev);
          }
      }
  
      SDL_Log("All done!\n");
  }
  
  
  int
  main(int argc, char **argv)
  {
      int devcount = 0;
  
  	/* Enable standard application logging */
      SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
  
      /* Load the SDL library */
      if (SDL_Init(SDL_INIT_AUDIO) < 0) {
          SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
          return (1);
      }
  
      SDL_Log("Using audio driver: %s\n", SDL_GetCurrentAudioDriver());
      
      devcount = SDL_GetNumAudioDevices(0);
      if (devcount < 1) {
          SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Don't see any specific audio devices!\n");
      } else {
          if (argv[1] == NULL) {
              argv[1] = "sample.wav";
          }
  
          /* Load the wave file into memory */
          if (SDL_LoadWAV(argv[1], &spec, &sound, &soundlen) == NULL) {
              SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", argv[1],
                      SDL_GetError());
          } else {
              test_multi_audio(devcount);
              SDL_FreeWAV(sound);
          }
      }
  
      SDL_Quit();
      return 0;
  }