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// Copyright 2018 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <atomic>
#include <cstring>
#include "audio_core/sdl2_sink.h"
#include "audio_core/stream.h"
#include "audio_core/time_stretch.h"
#include "common/assert.h"
#include "common/logging/log.h"
//#include "common/settings.h"
// Ignore -Wimplicit-fallthrough due to https://github.com/libsdl-org/SDL/issues/4307
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wimplicit-fallthrough"
#endif
#include <SDL.h>
#ifdef __clang__
#pragma clang diagnostic pop
#endif
namespace AudioCore {
class SDLSinkStream final : public SinkStream {
public:
SDLSinkStream(u32 sample_rate, u32 num_channels_, const std::string& output_device)
: num_channels{std::min(num_channels_, 6u)}, time_stretch{sample_rate, num_channels} {
SDL_AudioSpec spec;
spec.freq = sample_rate;
spec.channels = static_cast<u8>(num_channels);
spec.format = AUDIO_S16SYS;
spec.samples = 4096;
spec.callback = nullptr;
SDL_AudioSpec obtained;
if (output_device.empty()) {
dev = SDL_OpenAudioDevice(nullptr, 0, &spec, &obtained, 0);
} else {
dev = SDL_OpenAudioDevice(output_device.c_str(), 0, &spec, &obtained, 0);
}
if (dev == 0) {
LOG_CRITICAL(Audio_Sink, "Error opening sdl audio device: {}", SDL_GetError());
return;
}
SDL_PauseAudioDevice(dev, 0);
}
~SDLSinkStream() override {
if (dev == 0) {
return;
}
SDL_CloseAudioDevice(dev);
}
void EnqueueSamples(u32 source_num_channels, const std::vector<s16>& samples) override {
if (source_num_channels > num_channels) {
// Downsample 6 channels to 2
ASSERT_MSG(source_num_channels == 6, "Channel count must be 6");
std::vector<s16> buf;
buf.reserve(samples.size() * num_channels / source_num_channels);
for (std::size_t i = 0; i < samples.size(); i += source_num_channels) {
// Downmixing implementation taken from the ATSC standard
const s16 left{samples[i + 0]};
const s16 right{samples[i + 1]};
const s16 center{samples[i + 2]};
const s16 surround_left{samples[i + 4]};
const s16 surround_right{samples[i + 5]};
// Not used in the ATSC reference implementation
[[maybe_unused]] const s16 low_frequency_effects{samples[i + 3]};
constexpr s32 clev{707}; // center mixing level coefficient
constexpr s32 slev{707}; // surround mixing level coefficient
buf.push_back(static_cast<s16>(left + (clev * center / 1000) +
(slev * surround_left / 1000)));
buf.push_back(static_cast<s16>(right + (clev * center / 1000) +
(slev * surround_right / 1000)));
}
int ret = SDL_QueueAudio(dev, static_cast<const void*>(buf.data()),
static_cast<u32>(buf.size() * sizeof(s16)));
if (ret < 0)
LOG_WARNING(Audio_Sink, "Could not queue audio buffer: {}", SDL_GetError());
return;
}
int ret = SDL_QueueAudio(dev, static_cast<const void*>(samples.data()),
static_cast<u32>(samples.size() * sizeof(s16)));
if (ret < 0)
LOG_WARNING(Audio_Sink, "Could not queue audio buffer: {}", SDL_GetError());
}
std::size_t SamplesInQueue(u32 channel_count) const override {
if (dev == 0)
return 0;
return SDL_GetQueuedAudioSize(dev) / (channel_count * sizeof(s16));
}
void Flush() override {
should_flush = true;
}
u32 GetNumChannels() const {
return num_channels;
}
private:
SDL_AudioDeviceID dev = 0;
u32 num_channels{};
std::atomic<bool> should_flush{};
TimeStretcher time_stretch;
};
SDLSink::SDLSink(std::string_view target_device_name) {
if (!SDL_WasInit(SDL_INIT_AUDIO)) {
if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
LOG_CRITICAL(Audio_Sink, "SDL_InitSubSystem audio failed: {}", SDL_GetError());
return;
}
}
if (target_device_name != auto_device_name && !target_device_name.empty()) {
output_device = target_device_name;
} else {
output_device.clear();
}
}
SDLSink::~SDLSink() = default;
SinkStream& SDLSink::AcquireSinkStream(u32 sample_rate, u32 num_channels, const std::string&) {
sink_streams.push_back(
std::make_unique<SDLSinkStream>(sample_rate, num_channels, output_device));
return *sink_streams.back();
}
std::vector<std::string> ListSDLSinkDevices() {
std::vector<std::string> device_list;
if (!SDL_WasInit(SDL_INIT_AUDIO)) {
if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
LOG_CRITICAL(Audio_Sink, "SDL_InitSubSystem audio failed: {}", SDL_GetError());
return {};
}
}
const int device_count = SDL_GetNumAudioDevices(0);
for (int i = 0; i < device_count; ++i) {
device_list.emplace_back(SDL_GetAudioDeviceName(i, 0));
}
return device_list;
}
} // namespace AudioCore
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