bsnes/SDL/audio/sdl.c

88 lines
2.3 KiB
C

#include "audio.h"
#include <SDL.h>
#ifndef _WIN32
#define AUDIO_FREQUENCY 96000
#include <unistd.h>
#else
#include <Windows.h>
/* Windows (well, at least my VM) can't handle 96KHz sound well :( */
/* felsqualle says: For SDL 2.0.6+ using the WASAPI driver, the highest freq.
we can get is 48000. 96000 also works, but always has some faint crackling in
the audio, no matter how high or low I set the buffer length...
Not quite satisfied with that solution, because acc. to SDL2 docs,
96k + WASAPI *should* work. */
#define AUDIO_FREQUENCY 48000
#endif
/* Compatibility with older SDL versions */
#ifndef SDL_AUDIO_ALLOW_SAMPLES_CHANGE
#define SDL_AUDIO_ALLOW_SAMPLES_CHANGE 0
#endif
static SDL_AudioDeviceID device_id;
static SDL_AudioSpec want_aspec, have_aspec;
bool GB_audio_is_playing(void)
{
return SDL_GetAudioDeviceStatus(device_id) == SDL_AUDIO_PLAYING;
}
void GB_audio_set_paused(bool paused)
{
GB_audio_clear_queue();
SDL_PauseAudioDevice(device_id, paused);
}
void GB_audio_clear_queue(void)
{
SDL_ClearQueuedAudio(device_id);
}
unsigned GB_audio_get_frequency(void)
{
return have_aspec.freq;
}
size_t GB_audio_get_queue_length(void)
{
return SDL_GetQueuedAudioSize(device_id);
}
void GB_audio_queue_sample(GB_sample_t *sample)
{
SDL_QueueAudio(device_id, sample, sizeof(*sample));
}
void GB_audio_init(void)
{
/* Configure Audio */
memset(&want_aspec, 0, sizeof(want_aspec));
want_aspec.freq = AUDIO_FREQUENCY;
want_aspec.format = AUDIO_S16SYS;
want_aspec.channels = 2;
want_aspec.samples = 512;
SDL_version _sdl_version;
SDL_GetVersion(&_sdl_version);
unsigned sdl_version = _sdl_version.major * 1000 + _sdl_version.minor * 100 + _sdl_version.patch;
#ifndef _WIN32
/* SDL 2.0.5 on macOS and Linux introduced a bug where certain combinations of buffer lengths and frequencies
fail to produce audio correctly. */
if (sdl_version >= 2005) {
want_aspec.samples = 2048;
}
#else
if (sdl_version < 2006) {
/* Since WASAPI audio was introduced in SDL 2.0.6, we have to lower the audio frequency
to 44100 because otherwise we would get garbled audio output.*/
want_aspec.freq = 44100;
}
#endif
device_id = SDL_OpenAudioDevice(0, 0, &want_aspec, &have_aspec, SDL_AUDIO_ALLOW_FREQUENCY_CHANGE | SDL_AUDIO_ALLOW_SAMPLES_CHANGE);
}