Merge pull request #11 from hedge-dev/sdl2-audio

Implement SDL Audio

UnleashedRecomp/CMakeLists.txt

@@ -1,6 +1,8 @@
 project("UnleashedRecomp")
 set(TARGET_NAME "SWA")
 
+option(SWA_XAUDIO2 "Use XAudio2 for audio playback" OFF)
+
 add_compile_options(
     /fp:strict
     -march=sandybridge
@@ -57,9 +59,14 @@ set(SWA_GPU_CXX_SOURCES
 
 set(SWA_APU_CXX_SOURCES
     "apu/audio.cpp"
-    "apu/driver/xaudio_driver.cpp"
 )
 
+if(SWA_XAUDIO2)
+    list(APPEND SWA_APU_CXX_SOURCES "apu/driver/xaudio_driver.cpp")
+else()
+    list(APPEND SWA_APU_CXX_SOURCES "apu/driver/sdl2_driver.cpp")
+endif()
+
 set(SWA_HID_CXX_SOURCES
     "hid/hid.cpp"
     "hid/driver/sdl_hid.cpp"

UnleashedRecomp/apu/audio.h

@@ -1,5 +1,12 @@
 #pragma once
 
+#define XAUDIO_SAMPLES_HZ 48000
+#define XAUDIO_NUM_CHANNELS 6
+#define XAUDIO_SAMPLE_BITS 32
+
+// Number of samples in a frame
+#define XAUDIO_NUM_SAMPLES 256
+
 #ifdef SWA_IMPL
 void XAudioInitializeSystem();
 void XAudioRegisterClient(PPCFunc* callback, uint32_t param);

UnleashedRecomp/apu/driver/sdl2_driver.cpp

@@ -0,0 +1,101 @@
+#include "sdl2_driver.h"
+#include <cpu/code_cache.h>
+#include <cpu/guest_thread.h>
+#include <cpu/guest_code.h>
+#include <kernel/heap.h>
+
+#define SDLAUDIO_DRIVER_KEY (uint32_t)('SDLA')
+constexpr uint32_t g_semaphoreCount = 16;
+constexpr uint32_t g_audioFrameSize = XAUDIO_NUM_SAMPLES * XAUDIO_NUM_CHANNELS;
+
+PPCFunc* volatile g_clientCallback{};
+DWORD g_clientCallbackParam{}; // pointer in guest memory
+
+SDL_AudioDeviceID g_audioDevice{};
+SDL_sem* g_audioSemaphore{ SDL_CreateSemaphore(g_semaphoreCount) };
+uint32_t g_audioFrames[g_audioFrameSize * g_semaphoreCount];
+uint32_t g_audioFrameIndex = 0;
+uint32_t g_renderFrameIndex = 0; // Index of frame that's being rendered
+uint32_t g_numRenderFrames = 0; // Number of frames to render
+Mutex g_framesMutex{};
+
+static void SDLAudioCallback(void*, uint8_t* frames, int len)
+{
+    std::lock_guard guard{ g_framesMutex };
+    if (g_numRenderFrames == 0)
+    {
+        memset(frames, 0, len);
+    }
+    else
+    {
+        g_renderFrameIndex = (g_renderFrameIndex + 1) % g_semaphoreCount;
+        auto* srcFrames = &g_audioFrames[g_renderFrameIndex * g_audioFrameSize];
+        memcpy(frames, srcFrames, g_audioFrameSize * sizeof(float));
+        --g_numRenderFrames;
+    }
+    SDL_SemPost(g_audioSemaphore);
+}
+
+static PPC_FUNC(DriverLoop)
+{
+    GuestThread::SetThreadName(GetCurrentThreadId(), "Audio Driver");
+
+    while (true)
+    {
+        if (!g_clientCallback)
+        {
+            continue;
+        }
+
+        SDL_SemWait(g_audioSemaphore);
+        ctx.r3.u64 = g_clientCallbackParam;
+        GuestCode::Run((void*)g_clientCallback, &ctx);
+    }
+}
+
+void XAudioInitializeSystem()
+{
+    assert(g_audioSemaphore);
+
+    SDL_SetHint(SDL_HINT_AUDIO_CATEGORY, "playback");
+    SDL_SetHint(SDL_HINT_AUDIO_DEVICE_APP_NAME, "SWA");
+
+    auto err = SDL_InitSubSystem(SDL_INIT_AUDIO);
+    SDL_AudioSpec spec{};
+    spec.freq = XAUDIO_SAMPLES_HZ;
+    spec.format = AUDIO_F32SYS;
+    spec.channels = XAUDIO_NUM_CHANNELS;
+    spec.samples = XAUDIO_NUM_SAMPLES;
+    spec.callback = SDLAudioCallback;
+    g_audioDevice = SDL_OpenAudioDevice(nullptr, false, &spec, &spec, 0);
+    assert(g_audioDevice);
+
+    SDL_PauseAudioDevice(g_audioDevice, 0);
+    KeInsertHostFunction(SDLAUDIO_DRIVER_KEY, DriverLoop);
+    GuestThread::Start(SDLAUDIO_DRIVER_KEY, 0, 0, nullptr);
+}
+
+void XAudioRegisterClient(PPCFunc* callback, uint32_t param)
+{
+    auto* pClientParam = static_cast<uint32_t*>(g_userHeap.Alloc(sizeof(param)));
+    ByteSwap(param);
+    *pClientParam = param;
+    g_clientCallbackParam = g_memory.MapVirtual(pClientParam);
+
+    g_clientCallback = callback;
+}
+
+void XAudioSubmitFrame(void* samples)
+{
+    std::lock_guard guard{ g_framesMutex };
+    uint32_t* audioFrame = &g_audioFrames[g_audioFrameSize * g_audioFrameIndex];
+    g_audioFrameIndex = (g_audioFrameIndex + 1) % g_semaphoreCount;
+
+    for (size_t i = 0; i < XAUDIO_NUM_SAMPLES; i++)
+    {
+        for (size_t j = 0; j < XAUDIO_NUM_CHANNELS; j++)
+            audioFrame[i * XAUDIO_NUM_CHANNELS + j] = std::byteswap(((uint32_t*)samples)[j * XAUDIO_NUM_SAMPLES + i]);
+    }
+
+    ++g_numRenderFrames;
+}

UnleashedRecomp/apu/driver/sdl2_driver.h

@@ -0,0 +1,3 @@
+#pragma once
+#include <SDL.h>
+#include <apu/audio.h>

UnleashedRecomp/apu/driver/xaudio_driver.cpp

@@ -9,7 +9,7 @@
 
 #define XAUDIO_DRIVER_KEY (uint32_t)('XAUD')
 
-PPCFunc* g_clientCallback{};
+PPCFunc* volatile g_clientCallback{};
 DWORD g_clientCallbackParam{}; // pointer in guest memory
 DWORD g_driverThread{};
 
@@ -49,8 +49,6 @@ PPC_FUNC(DriverLoop)
     {
         if (!g_clientCallback)
         {
-            // NOTE: This if statement doesn't get compiled in without this barrier. What?
-            _ReadBarrier();
             continue;
         }
 
@@ -77,9 +75,9 @@ void XAudioInitializeSystem()
     WAVEFORMATIEEEFLOATEX format{};
     format.Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
     format.Format.cbSize = sizeof(format) - sizeof(format.Format);
-    format.Format.nChannels = 6;
+    format.Format.nChannels = XAUDIO_NUM_CHANNELS;
-    format.Format.nSamplesPerSec = 48000;
+    format.Format.nSamplesPerSec = XAUDIO_SAMPLES_HZ;
-    format.Format.wBitsPerSample = 32;
+    format.Format.wBitsPerSample = XAUDIO_SAMPLE_BITS;
     format.Format.nBlockAlign = (format.Format.nChannels * format.Format.wBitsPerSample) / 8;
     format.Format.nAvgBytesPerSec = format.Format.nSamplesPerSec * format.Format.nBlockAlign;
 
@@ -110,16 +108,16 @@ void XAudioSubmitFrame(void* samples)
     uint32_t* audioFrame = &g_audioFrames[g_audioFrameSize * g_audioFrameIndex];
     g_audioFrameIndex = (g_audioFrameIndex + 1) % g_semaphoreCount;
 
-    for (size_t i = 0; i < 256; i++)
+    for (size_t i = 0; i < XAUDIO_NUM_SAMPLES; i++)
     {
         for (size_t j = 0; j < 6; j++)
-            audioFrame[i * 6 + j] = std::byteswap(((uint32_t*)samples)[j * 256 + i]);
+            audioFrame[i * XAUDIO_NUM_CHANNELS + j] = std::byteswap(((uint32_t*)samples)[j * XAUDIO_NUM_SAMPLES + i]);
     }
 
     XAUDIO2_BUFFER buffer{};
     buffer.pAudioData = (BYTE*)audioFrame;
-    buffer.AudioBytes = 256 * 6 * sizeof(float);
+    buffer.AudioBytes = XAUDIO_NUM_SAMPLES * XAUDIO_NUM_CHANNELS * sizeof(float);
-    buffer.PlayLength = 256;
+    buffer.PlayLength = XAUDIO_NUM_SAMPLES;
 
     g_sourceVoice->SubmitSourceBuffer(&buffer);
 }

UnleashedRecomp/apu/driver/xaudio_driver.h

@@ -1 +1,2 @@
 #pragma once
+#include <apu/audio.h>