Refactor Audio

src/backend/core/mmio/AI.cpp

@@ -2,7 +2,6 @@
 #include <log.hpp>
 #include <core/Mem.hpp>
 #include <core/registers/Registers.hpp>
-#include <Audio.hpp>
 
 namespace n64 {
 void AI::Reset() {
@@ -56,12 +55,12 @@ void AI::Write(Mem& mem, Registers& regs, u32 addr, u32 val) {
       InterruptLower(mem.mmio.mi, regs, Interrupt::AI);
       break;
     case 0x04500010: {
-      u32 old_dac_freq = dac.freq;
+      u32 oldDacFreq = dac.freq;
       dacRate = val & 0x3FFF;
       dac.freq = std::max(1u, GetVideoFrequency(mem.IsROMPAL()) / (dacRate + 1));
       dac.period = N64_CPU_FREQ / dac.freq;
-      if(old_dac_freq != dac.freq) {
-        AdjustSampleRate(dac.freq);
+      if(oldDacFreq != dac.freq) {
+        device.AdjustSampleRate(dac.freq);
       }
     } break;
     case 0x04500014:
@@ -87,7 +86,7 @@ void AI::Step(Mem& mem, Registers& regs, u32 cpuCycles, float volumeL, float vol
       s16 r = s16(data);
 
       if(volumeR > 0 && volumeL > 0) {
-        PushSample((float) l / INT16_MAX, volumeL, (float) r / INT16_MAX, volumeR);
+        device.PushSample((float) l / INT16_MAX, volumeL, (float) r / INT16_MAX, volumeR);
       }
 
       u32 addrLo = (dmaAddr[0] + 4) & 0x1FFF;

src/backend/core/mmio/AI.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <common.hpp>
 #include <core/mmio/Interrupt.hpp>
+#include "Audio.hpp"
 
 namespace n64 {
 struct Mem;
@@ -20,6 +21,7 @@ struct AI {
   u32 dmaAddr[2]{};
   bool dmaAddrCarry{};
   u32 cycles{};
+  AudioDevice device;
 
   struct {
     u32 freq{44100};

src/backend/core/mmio/Audio.cpp

@@ -1,6 +1,5 @@
 #include <Audio.hpp>
 #include <log.hpp>
-#include <SDL2/SDL.h>
 
 namespace n64 {
 #define AUDIO_SAMPLE_RATE 44100
@@ -8,56 +7,47 @@ namespace n64 {
 #define SYSTEM_SAMPLE_SIZE 4
 #define BYTES_PER_HALF_SECOND (((float)AUDIO_SAMPLE_RATE / 2) * SYSTEM_SAMPLE_SIZE)
 
-static SDL_AudioStream* audioStream = nullptr;
-SDL_mutex* audioStreamMutex;
-SDL_AudioSpec audioSpec;
-SDL_AudioSpec request;
-SDL_AudioDeviceID audioDev{};
-
-#define LockAudioMutex() SDL_LockMutex(audioStreamMutex)
-#define UnlockAudioMutex() SDL_UnlockMutex(audioStreamMutex)
-
-void audioCallback(void*, Uint8* stream, int length) {
+void audioCallback(void* user, Uint8* stream, int length) {
+  auto audioDevice = (AudioDevice*)user;
   int gotten = 0;
-  LockAudioMutex();
-  int available = SDL_AudioStreamAvailable(audioStream);
+  audioDevice->LockMutex();
+  int available = SDL_AudioStreamAvailable(audioDevice->GetStream());
 
   if (available > 0) {
-    gotten = SDL_AudioStreamGet(audioStream, stream, length);
+    gotten = SDL_AudioStreamGet(audioDevice->GetStream(), stream, length);
   }
-  UnlockAudioMutex();
+  audioDevice->UnlockMutex();
 
-  int gotten_samples = (int)(gotten / sizeof(float));
+  int gottenSamples = (int)(gotten / sizeof(float));
   auto* out = (float*)stream;
-  out += gotten_samples;
+  out += gottenSamples;
 
-  for (int i = gotten_samples; i < length / sizeof(float); i++) {
+  for (int i = gottenSamples; i < length / sizeof(float); i++) {
     float sample = 0;
     *out++ = sample;
   }
 }
 
-void InitAudio() {
+AudioDevice::AudioDevice() {
   SDL_InitSubSystem(SDL_INIT_AUDIO);
   AdjustSampleRate(AUDIO_SAMPLE_RATE);
-  memset(&request, 0, sizeof(request));
 
   request.freq = AUDIO_SAMPLE_RATE;
   request.format = SYSTEM_SAMPLE_FORMAT;
   request.channels = 2;
   request.samples = 1024;
   request.callback = audioCallback;
-  request.userdata = nullptr;
+  request.userdata = (void*)this;
 
-  if(!audioDev) {
-    audioDev = SDL_OpenAudioDevice(nullptr, 0, &request, &audioSpec, 0);
+  if(!handle) {
+    handle = SDL_OpenAudioDevice(nullptr, 0, &request, &audioSpec, 0);
   }
 
-  if(!audioDev) {
+  if(!handle) {
     Util::panic("Failed to initialize SDL Audio: {}", SDL_GetError());
   }
 
-  SDL_PauseAudioDevice(audioDev, false);
+  SDL_PauseAudioDevice(handle, false);
 
   audioStreamMutex = SDL_CreateMutex();
 
@@ -66,7 +56,7 @@ void InitAudio() {
   }
 }
 
-void PushSample(float left, float volumeL, float right, float volumeR) {
+void AudioDevice::PushSample(float left, float volumeL, float right, float volumeR) {
   float adjustedL = left * volumeL;
   float adjustedR = right * volumeR;
   float samples[2]{ adjustedL, adjustedR };
@@ -77,12 +67,11 @@ void PushSample(float left, float volumeL, float right, float volumeR) {
   }
 }
 
-void AdjustSampleRate(int sampleRate) {
-  LockAudioMutex();
+void AudioDevice::AdjustSampleRate(int sampleRate) {
+  LockMutex();
   if(audioStream) SDL_FreeAudioStream(audioStream);
 
   audioStream = SDL_NewAudioStream(AUDIO_F32SYS, 2, sampleRate, SYSTEM_SAMPLE_FORMAT, 2, AUDIO_SAMPLE_RATE);
-  UnlockAudioMutex();
+  UnlockMutex();
 }
-
 }

src/backend/core/mmio/Audio.hpp

@@ -1,8 +1,31 @@
 #pragma once
 #include <common.hpp>
+#include <SDL2/SDL.h>
 
 namespace n64 {
-void PushSample(float, float, float, float);
-void InitAudio();
-void AdjustSampleRate(int);
+struct AudioDevice {
+  AudioDevice();
+  ~AudioDevice() {
+    SDL_FreeAudioStream(audioStream);
+    SDL_DestroyMutex(audioStreamMutex);
+  }
+
+  void PushSample(float, float, float, float);
+  void AdjustSampleRate(int);
+  void LockMutex() {
+    SDL_LockMutex(audioStreamMutex);
+  }
+  void UnlockMutex() {
+    SDL_UnlockMutex(audioStreamMutex);
+  }
+
+  SDL_AudioStream* GetStream() { return audioStream; }
+private:
+  SDL_AudioStream* audioStream = nullptr;
+  SDL_mutex* audioStreamMutex = nullptr;
+  SDL_AudioSpec audioSpec{};
+  SDL_AudioSpec request{};
+  SDL_AudioDeviceID handle{};
+};
+
 }

src/frontend/EmuThread.cpp

@@ -9,7 +9,7 @@ EmuThread::EmuThread(std::unique_ptr<QtInstanceFactory>&& instance, std::unique_
 [[noreturn]] void EmuThread::run() noexcept {
   LoadWSIPlatform(instance.get(), std::move(wsiPlatform), std::move(windowInfo));
   LoadParallelRDP(core->cpu->mem.GetRDRAM());
-  n64::InitAudio();
+
   while (true) {
     if (!core->pause) {
       core->Run(settings->getVolumeL(), settings->getVolumeR());