api8/src/audio.c

#include "../includes/audio.h"
#include "SDL_mixer.h"
#include <stdio.h>

// Stocke les données à propos de la musique
static double average;

static int _channel;

double averageMusic(void) { return average; }

void callback(void *_, Uint8 *stream, int size) {
  int i = 0;
  double tmp = 0.;
  for (signed short *stream16 = (signed short *)stream; i < size / 2; ++i) {
    tmp += stream16[i] / ((1 << 15) + 1.);
  }
  average = fabs(tmp / (i / 100.));
}

void initMusic(Mix_Chunk *music, const char *filename) {
  if (!Mix_Init(MIX_INIT_MID)) {
    fprintf(stderr, "Erreur Mix_Init\n");
    exit(2);
  }

  if (Mix_OpenAudio(MIX_DEFAULT_FREQUENCY, MIX_DEFAULT_FORMAT, 1, 2048)) {
    fprintf(stderr, "Erreur Mix_OpenAudio\n");
    exit(2);
  };

  if (!(music = Mix_LoadWAV(filename))) {
    fprintf(stderr, "Erreur Mix_LoadWAV for '%s'\n", filename);
    exit(2);
  }

  Mix_SetPostMix(callback, NULL);

  if ((_channel = Mix_PlayChannel(-1, music, -1)) == -1) {
    fprintf(stderr, "Erreur Mix_PlayChannel\n");
    exit(2);
  };
}

void freeMusic(Mix_Chunk *music) {
  if (music) {
    if (Mix_Playing(_channel)) {
      Mix_HaltChannel(_channel);
    }
    Mix_FreeChunk(music);
    music = NULL;
  }

  Mix_CloseAudio();
  Mix_Quit();
}