mini_al is a single file library for playing and recording audio. It's written in C (compilable as C++) and released into the public domain. It has a heavy focus on simplicity, and features a simple API and a very simple build system.

Features

Public domain.
Single file.
Compilable as both C and C++.
Easy to build.
- Does not require linking to anything on the Windows build and only -ldl on Linux.
- It should Just Work out of the box, without the need to download and install any dependencies. (Note that some older versions of MinGW/MinGW-64 don't include WASAPI and DirectSound headers which may require manual installation. Plans are in place to work around this in a future update.)
- The header section does not include any platform specific headers.
A very simple API.
Transparent data structures with direct access to internal data.
Supports both playback and capture on all backends.
Automatic format conversion.
- Sample format conversion.
- Sample rate conversion.
  - Sample rate conversion is currently low quality, but a higher quality implementation is planned.
- Channel mapping/layout.
- Channel mixing (converting mono to 5.1, etc.)
MP3, Vorbis, FLAC and WAV decoding
- This depends on external single file libraries which can be found in the "extras" folder.

Supported Platforms

Windows (XP+)
Linux
BSD
Android
Emscripten / HTML5

macOS and iOS support is coming soon(ish) via Core Audio. Unofficial support is enabled via the PulseAudio, JACK, OpenAL and SDL backends, however I have not tested these personally.

Backends

WASAPI
DirectSound
WinMM
ALSA
PulseAudio
JACK
OSS
OpenSL|ES (Android only)
OpenAL
SDL
Null (Silence)

Simple Playback Example

#define DR_FLAC_IMPLEMENTATION
#include "../extras/dr_flac.h"  // Enables FLAC decoding.
#define DR_MP3_IMPLEMENTATION
#include "../extras/dr_mp3.h"   // Enables MP3 decoding.
#define DR_WAV_IMPLEMENTATION
#include "../extras/dr_wav.h"   // Enables WAV decoding.

#define MAL_IMPLEMENTATION
#include "../mini_al.h"

#include <stdio.h>

// This is the function that's used for sending more data to the device for playback.
mal_uint32 on_send_frames_to_device(mal_device* pDevice, mal_uint32 frameCount, void* pSamples)
{
    mal_decoder* pDecoder = (mal_decoder*)pDevice->pUserData;
    if (pDecoder == NULL) {
        return 0;
    }

    return (mal_uint32)mal_decoder_read(pDecoder, frameCount, pSamples);
}

int main(int argc, char** argv)
{
    if (argc < 2) {
        printf("No input file.\n");
        return -1;
    }

    mal_decoder decoder;
    mal_result result = mal_decoder_init_file(argv[1], NULL, &decoder);
    if (result != MAL_SUCCESS) {
        return -2;
    }

    mal_device_config config = mal_device_config_init_playback(
        decoder.outputFormat,
        decoder.outputChannels,
        decoder.outputSampleRate,
        on_send_frames_to_device);

    mal_device device;
    if (mal_device_init(NULL, mal_device_type_playback, NULL, &config, &decoder, &device) != MAL_SUCCESS) {
        printf("Failed to open playback device.\n");
        mal_decoder_uninit(&decoder);
        return -3;
    }

    if (mal_device_start(&device) != MAL_SUCCESS) {
        printf("Failed to start playback device.\n");
        mal_device_uninit(&device);
        mal_decoder_uninit(&decoder);
        return -4;
    }

    printf("Press Enter to quit...");
    getchar();

    mal_device_uninit(&device);
    mal_decoder_uninit(&decoder);

    return 0;
}

MP3/Vorbis/FLAC/WAV Decoding

mini_al includes a decoding API which supports the following backends:

FLAC via dr_flac
MP3 via dr_mp3
WAV via dr_wav
Vorbis via stb_vorbis

Copies of these libraries can be found in the "extras" folder. You may also want to look at the libraries below, but they are not supported by the mini_al decoder API. If you know of any other single file libraries I can add to this list, let me know. Preferably public domain or MIT.

To enable support for a decoding backend, all you need to do is #include the header section of the relevant backend library before the implementation of mini_al, like so:

#include "dr_flac.h"    // Enables FLAC decoding.
#include "dr_mp3.h"     // Enables MP3 decoding.
#include "dr_wav.h"     // Enables WAV decoding.

#define MAL_IMPLEMENTATION
#include "mini_al.h"