gistfile1.txt

#include <SDL2/SDL.h>
#include <stdio.h>

/*
--- Want
Rate : 44444
Channels : 2
Samples : 4096
Size : 0
Format : 0x008120
--- Have
Rate : 44444
Channels : 2
Samples : 4096
Size : 32768
Format : 0x008120
 */

static void SDLCALL MyAudioCallback (void *userdata, Uint8 * stream, int len)
{
}

void printAudioSpec(const SDL_AudioSpec &spec)
{
    printf("Rate : %d\n", spec.freq);
    printf("Channels : %d\n", spec.channels);
    printf("Samples : %d\n", spec.samples);
    printf("Size : %d\n", spec.size);
    printf("Format : %#08x\n", spec.format);
}

int main()
{
    SDL_Init(SDL_INIT_EVERYTHING);

    SDL_AudioSpec want, have;
    SDL_AudioDeviceID dev;

    SDL_memset(&want, 0, sizeof(want));
    SDL_memset(&have, 0, sizeof(have));

    want.freq = 44444;
    want.format = AUDIO_F32;
    want.channels = 2;
    want.samples = 4096;
    want.callback = MyAudioCallback;
    dev = SDL_OpenAudioDevice(NULL, 0, &want, &have, SDL_AUDIO_ALLOW_FORMAT_CHANGE|SDL_AUDIO_ALLOW_FREQUENCY_CHANGE);

    if (!dev)
        return 1;

    printf("--- Want\n");
    printAudioSpec(want);
    printf("--- Have\n");
    printAudioSpec(have);

    return 0;
}