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// Copyright 2016 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <list>
#include <numeric>
#include <vector>
#include <SDL.h>
#include "audio_core/audio_core.h"
#include "audio_core/sdl2_sink.h"
#include "common/assert.h"
#include "common/logging/log.h"
namespace AudioCore {
struct SDL2Sink::Impl {
unsigned int sample_rate = 0;
SDL_AudioDeviceID audio_device_id = 0;
std::list<std::vector<s16>> queue;
static void Callback(void* impl_, u8* buffer, int buffer_size_in_bytes);
};
SDL2Sink::SDL2Sink() : impl(std::make_unique<Impl>()) {
if (SDL_Init(SDL_INIT_AUDIO) < 0) {
LOG_CRITICAL(Audio_Sink, "SDL_Init(SDL_INIT_AUDIO) failed");
impl->audio_device_id = 0;
return;
}
SDL_AudioSpec desired_audiospec;
SDL_zero(desired_audiospec);
desired_audiospec.format = AUDIO_S16;
desired_audiospec.channels = 2;
desired_audiospec.freq = native_sample_rate;
desired_audiospec.samples = 512;
desired_audiospec.userdata = impl.get();
desired_audiospec.callback = &Impl::Callback;
SDL_AudioSpec obtained_audiospec;
SDL_zero(obtained_audiospec);
impl->audio_device_id =
SDL_OpenAudioDevice(nullptr, false, &desired_audiospec, &obtained_audiospec, 0);
if (impl->audio_device_id <= 0) {
LOG_CRITICAL(Audio_Sink, "SDL_OpenAudioDevice failed");
return;
}
impl->sample_rate = obtained_audiospec.freq;
// SDL2 audio devices start out paused, unpause it:
SDL_PauseAudioDevice(impl->audio_device_id, 0);
}
SDL2Sink::~SDL2Sink() {
if (impl->audio_device_id <= 0)
return;
SDL_CloseAudioDevice(impl->audio_device_id);
}
unsigned int SDL2Sink::GetNativeSampleRate() const {
if (impl->audio_device_id <= 0)
return native_sample_rate;
return impl->sample_rate;
}
void SDL2Sink::EnqueueSamples(const s16* samples, size_t sample_count) {
if (impl->audio_device_id <= 0)
return;
SDL_LockAudioDevice(impl->audio_device_id);
impl->queue.emplace_back(samples, samples + sample_count * 2);
SDL_UnlockAudioDevice(impl->audio_device_id);
}
size_t SDL2Sink::SamplesInQueue() const {
if (impl->audio_device_id <= 0)
return 0;
SDL_LockAudioDevice(impl->audio_device_id);
size_t total_size = std::accumulate(impl->queue.begin(), impl->queue.end(),
static_cast<size_t>(0), [](size_t sum, const auto& buffer) {
// Division by two because each stereo sample is made of
// two s16.
return sum + buffer.size() / 2;
});
SDL_UnlockAudioDevice(impl->audio_device_id);
return total_size;
}
void SDL2Sink::Impl::Callback(void* impl_, u8* buffer, int buffer_size_in_bytes) {
Impl* impl = reinterpret_cast<Impl*>(impl_);
size_t remaining_size = static_cast<size_t>(buffer_size_in_bytes) /
sizeof(s16); // Keep track of size in 16-bit increments.
while (remaining_size > 0 && !impl->queue.empty()) {
if (impl->queue.front().size() <= remaining_size) {
memcpy(buffer, impl->queue.front().data(), impl->queue.front().size() * sizeof(s16));
buffer += impl->queue.front().size() * sizeof(s16);
remaining_size -= impl->queue.front().size();
impl->queue.pop_front();
} else {
memcpy(buffer, impl->queue.front().data(), remaining_size * sizeof(s16));
buffer += remaining_size * sizeof(s16);
impl->queue.front().erase(impl->queue.front().begin(),
impl->queue.front().begin() + remaining_size);
remaining_size = 0;
}
}
if (remaining_size > 0) {
memset(buffer, 0, remaining_size * sizeof(s16));
}
}
} // namespace AudioCore
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