Add volume slider & mute audio settings

src/config.cpp

@@ -99,6 +99,11 @@ void EmulatorConfig::load() {
 			
 			audioEnabled = toml::find_or<toml::boolean>(audio, "EnableAudio", false);
 			aacEnabled = toml::find_or<toml::boolean>(audio, "EnableAACAudio", true);
+
+			audioDeviceConfig.muteAudio = toml::find_or<toml::boolean>(audio, "MuteAudio", false);
+			// Our volume ranges from 0.0 (muted) to 2.0 (boosted, using a logarithmic scale). 1.0 is the "default" volume, ie we don't adjust the PCM
+			// samples at all.
+			audioDeviceConfig.volumeRaw = float(std::clamp(toml::find_or<toml::floating>(audio, "AudioVolume", 1.0), 0.0, 2.0));
 		}
 	}
 
@@ -170,6 +175,8 @@ void EmulatorConfig::save() {
 	data["Audio"]["DSPEmulation"] = std::string(Audio::DSPCore::typeToString(dspType));
 	data["Audio"]["EnableAudio"] = audioEnabled;
 	data["Audio"]["EnableAACAudio"] = aacEnabled;
+	data["Audio"]["MuteAudio"] = audioDeviceConfig.muteAudio;
+	data["Audio"]["AudioVolume"] = double(audioDeviceConfig.volumeRaw);
 
 	data["Battery"]["ChargerPlugged"] = chargerPlugged;
 	data["Battery"]["BatteryPercentage"] = batteryPercentage;

src/core/audio/aac_decoder.cpp

@@ -103,10 +103,8 @@ void AAC::Decoder::decode(AAC::Message& response, const AAC::Message& request, A
 				}
 			} else {
 				// If audio is not enabled, push 0s
-				for (int sample = 0; sample < info->frameSize; sample++) {
-					for (int stream = 0; stream < channels; stream++) {
-						audioStreams[stream].push_back(0);
-					}
+				for (int stream = 0; stream < channels; stream++) {
+					audioStreams[stream].resize(audioStreams[stream].size() + info->frameSize, 0);
 				}
 			}
 		} else {

src/core/audio/hle_core.cpp

@@ -715,10 +715,7 @@ namespace Audio {
 				response.command = request.command;
 				response.mode = request.mode;
 
-				// We allow disabling AAC audio. Mostly useful for debugging & figuring out if an audio track is AAC or not.
-				if (settings.aacEnabled) {
-					aacDecoder->decode(response, request, [this](u32 paddr) { return getPointerPhys<u8>(paddr); });
-				}
+				aacDecoder->decode(response, request, [this](u32 paddr) { return getPointerPhys<u8>(paddr); }, settings.aacEnabled);
 				break;
 			}
 

src/core/audio/miniaudio_device.cpp

@@ -1,10 +1,14 @@
 #include "audio/miniaudio_device.hpp"
 
+#include <algorithm>
+#include <cmath>
 #include <cstring>
+#include <limits>
 
 #include "helpers.hpp"
 
-MiniAudioDevice::MiniAudioDevice() : initialized(false), running(false), samples(nullptr) {}
+MiniAudioDevice::MiniAudioDevice(AudioDeviceConfig& audioSettings)
+	: initialized(false), running(false), samples(nullptr), audioSettings(audioSettings) {}
 
 void MiniAudioDevice::init(Samples& samples, bool safe) {
 	this->samples = &samples;
@@ -106,6 +110,40 @@ void MiniAudioDevice::init(Samples& samples, bool safe) {
 			std::memcpy(&self->lastStereoSample[0], &output[(samplesWritten - 1) * 2], sizeof(lastStereoSample));
 		}
 
+		// Adjust the volume of our samples based on the emulator's volume slider
+		float audioVolume = self->audioSettings.getVolume();
+		// If volume is 1.0 we don't need to do anything
+		if (audioVolume != 1.0f) {
+			s16* sample = output;
+
+			// If our volume is > 1.0 then we boost samples using a logarithmic scale,
+			// In this case we also have to clamp samples to make sure they don't wrap around
+			if (audioVolume > 1.0f) {
+				audioVolume = 0.6 + 20 * std::log10(audioVolume);
+
+				constexpr s32 min = s32(std::numeric_limits<s16>::min());
+				constexpr s32 max = s32(std::numeric_limits<s16>::max());
+
+				for (usize i = 0; i < samplesWritten; i += 2) {
+					s16 l = s16(std::clamp<s32>(s32(float(sample[0]) * audioVolume), min, max));
+					s16 r = s16(std::clamp<s32>(s32(float(sample[1]) * audioVolume), min, max));
+
+					*sample++ = l;
+					*sample++ = r;
+				}
+			} else {
+				// If our volume is in [0.0, 1.0) then just multiply by the volume. No need to clamp, since there is no danger of our samples wrapping
+				// around due to overflow
+				for (usize i = 0; i < samplesWritten; i += 2) {
+					s16 l = s16(float(sample[0]) * audioVolume);
+					s16 r = s16(float(sample[1]) * audioVolume);
+
+					*sample++ = l;
+					*sample++ = r;
+				}
+			}
+		}
+
 		// If underruning, copy the last output sample
 		{
 			s16* pointer = &output[samplesWritten * 2];

src/emulator.cpp

@@ -20,7 +20,7 @@ __declspec(dllexport) DWORD AmdPowerXpressRequestHighPerformance = 1;
 
 Emulator::Emulator()
 	: config(getConfigPath()), kernel(cpu, memory, gpu, config), cpu(memory, kernel, *this), gpu(memory, config), memory(cpu.getTicksRef(), config),
-	  cheats(memory, kernel.getServiceManager().getHID()), lua(*this), running(false)
+	  cheats(memory, kernel.getServiceManager().getHID()), audioDevice(config.audioDeviceConfig), lua(*this), running(false)
 #ifdef PANDA3DS_ENABLE_HTTP_SERVER
 	  ,
 	  httpServer(this)