Playing Audio with SDL2

To play audio with SDL2, you can use the SDL_mixer extension library, which provides a simple API for loading and playing audio files.

First, make sure you have SDL_mixer installed and added to your project (similar to how SDL_image and SDL_ttf were added in the lesson).

Here's a simple example of loading and playing an audio file with SDL_mixer:

1#include <SDL.h>
2#include <SDL_mixer.h>
3
4int main(int argc, char** argv) {
5  SDL_Init(SDL_INIT_AUDIO);
6
7  Mix_OpenAudio(44100, MIX_DEFAULT_FORMAT,
8    2, 2048);
9
10  Mix_Music* music{Mix_LoadMUS("music.mp3")};  
11  if (!music) {
12    // Error handling
13    return 1;
14  }
15
16  Mix_PlayMusic(music, -1);  
17
18  // Main loop
19  // ...
20
21  bool quit = false;
22  while (!quit) {
23    SDL_Event e;
24    while (SDL_PollEvent(&e)) {
25      if (e.type == SDL_QUIT) {
26        quit = true;
27      }
28    }
29  }
30
31  Mix_FreeMusic(music);
32  Mix_CloseAudio();
33  SDL_Quit();
34
35  return 0;
36}

This code:

1. Initializes the SDL audio subsystem with SDL_Init(SDL_INIT_AUDIO)
2. Opens the audio device with Mix_OpenAudio
3. Loads an audio file with Mix_LoadMUS
4. Plays the loaded audio with Mix_PlayMusic (-1 means loop indefinitely)
5. Frees the audio resources when done

SDL_mixer supports various audio formats like MP3, WAV, OGG, and MOD. You can also load and play short sound effects using Mix_LoadWAV and Mix_PlayChannel.

Remember to link against the SDL_mixer library when compiling:

1g++ ... -lSDL2 -lSDL2_mixer ...