Play one sound after another with SDL_mixer? - c++

Question

I have 4 sounds. I need play sound 1, when it finishes, automatically play sound 2; when sound 2 finishes, automatically play sound 3. Soun 3 finishes, play sound 4.... I'm using SDL Mixer 2.0, no SDL Sound...Is there a way?
int main() {
int frequencia = 22050;
Uint16 formato = AUDIO_S16SYS;
int canal = 2; // 1 mono; 2 = stereo;
int buffer = 4096;
Mix_OpenAudio(frequencia, formato, canal, buffer);
Mix_Chunk* sound_1;
Mix_Chunk* sound_2;
Mix_Chunk* sound_3;
Mix_Chunk* sound_4;
som_1 = Mix_LoadWAV("D:\\sound1.wav");
som_2 = Mix_LoadWAV("D:\\sound1.wav");
som_3 = Mix_LoadWAV("D:\\sound1.wav");
som_4 = Mix_LoadWAV("D:\\sound1.wav");
Mix_PlayChannel(-1, sound_1, 0);
Mix_PlayChannel(1, sound_2, 0);
Mix_PlayChannel(2, sound_3, 0);
Mix_PlayChannel(3, sound_4, 0);
return 0;
}

Answer 1

Check in a loop whether the channel is still playing using Mix_Playing(), and add a delay using SDL_Delay() to prevent the loop from consuming all available CPU time.
(In this example, I changed your first call to Mix_PlayChannel() from -1 to 1.)
Mix_PlayChannel(1, sound_1, 0);
while (Mix_Playing(1) != 0) {
SDL_Delay(200); // wait 200 milliseconds
}
Mix_PlayChannel(2, sound_2, 0);
while (Mix_Playing(2) != 0) {
SDL_Delay(200); // wait 200 milliseconds
}
// etc.
You should probably wrap that into a function instead so that you don't repeat what is basically the same code over and over again:
void PlayAndWait(int channel, Mix_Chunk* chunk, int loops)
{
channel = Mix_PlayChannel(channel, chunk, loops);
if (channel < 0) {
return; // error
}
while (Mix_Playing(channel) != 0) {
SDL_Delay(200);
}
}
// ...
PlayAndWait(-1, sound_1, 0);
PlayAndWait(1, sound_2, 0);
PlayAndWait(2, sound_3, 0);
PlayAndWait(3, sound_3, 0);