Decode a .wav file into signed 32-bit PCM samples with Dr Wav, then write those samples to the audio server via Pulse Audio.

wav-pulse-example.c

// compile with `gcc wav-pulse-example.c -lpulse-simple -lpulse -o wav-pulse-example`
// run with `./wav-pulse-example <path_to_wav_file>`

#include <stdio.h>
#include <stdlib.h>

// install dev libs from package "pulseaudio-libs-devel" (rpm) or "libpulse-dev" (deb)
#include <pulse/simple.h>
#include <pulse/error.h>

// Download dr_wav.h from: https://mackron.github.io/dr_wav
// put it in the same directory as this file
#define DR_WAV_IMPLEMENTATION
#include "dr_wav.h"

int main(int argc, char *argv[])
{
    drwav* wav = drwav_open_file(argv[1]);
    if (wav == NULL) {
        return -1;
    }

    size_t sampleDataSize = (size_t) wav->totalSampleCount * sizeof(int32_t);
    int32_t *sampleData = (int32_t *) malloc(sampleDataSize);
    drwav_read_s32(wav, wav->totalSampleCount, sampleData);

    drwav_close(wav);

    pa_simple *pulse;
    pa_sample_spec pulseSpec = {
        .format = PA_SAMPLE_S16LE,
        .channels = 2,
        .rate = 44100,
    };

    pulse = pa_simple_new(NULL, "TestApp", PA_STREAM_PLAYBACK, NULL,
                          "Music", &pulseSpec, NULL, NULL, NULL);

    int error;
    if (pa_simple_write(pulse, sampleData, sampleDataSize, &error) < 0) {
        fprintf(stderr, "pa_simple_write() failed: %s\n", pa_strerror(error));
    }

    pa_simple_free(pulse);
}