cellMic: Implement SIGSTATE_MICENG

rpcs3/Emu/Cell/Modules/cellMic.cpp

@@ -8,6 +8,7 @@
 #include <Emu/Cell/lv2/sys_event.h>
 
 #include <numeric>
+#include <cmath>
 
 #include "3rdparty/OpenAL/openal-soft/include/AL/alext.h"
 
@@ -575,6 +576,28 @@ bool microphone_device::has_data() const
 	return mic_registered && mic_opened && mic_started && (rbuf_raw.has_data() || rbuf_dsp.has_data());
 }
 
+f32 microphone_device::calculate_energy_level()
+{
+	const auto& buffer = device_type == microphone_handler::real_singstar ? ::at32(devices, 0).buf : temp_buf;
+	const size_t num_samples = buffer.size() / sizeof(s16);
+
+	f64 sum_squares = 0.0;
+
+	for (usz i = 0; i < num_samples; i++)
+	{
+		const be_t<s16> sample = read_from_ptr<be_t<s16>>(buffer, i * sizeof(s16));
+		const f64 normalized_sample = static_cast<f64>(sample) / -std::numeric_limits<s16>::min();
+		sum_squares += normalized_sample * normalized_sample;
+	}
+
+	const f32 rms = std::sqrt(sum_squares / num_samples);
+	const f32 decibels_max = 90.0f;
+	const f32 decibels_relative = 20.0f * std::log10(std::max(rms, 0.00001f));
+	const f32 decibels = decibels_max + (decibels_relative * 0.5f);
+
+	return std::clamp(decibels, 40.0f, decibels_max);
+}
+
 u32 microphone_device::capture_audio()
 {
 	ensure(sample_size > 0);
@@ -1089,7 +1112,7 @@ error_code cellMicGetSignalState(s32 dev_num, CellMicSignalState sig_state, vm::
 		*fval = 1.0f; // No gain applied
 		break;
 	case CELLMIC_SIGSTATE_MICENG:
-		*fval = 40.0f; // 40 decibels
+		*fval = device.calculate_energy_level();
 		break;
 	case CELLMIC_SIGSTATE_SPKENG:
 		*fval = 10.0f; // 10 decibels

rpcs3/Emu/Cell/Modules/cellMic.h

@@ -289,6 +289,8 @@ public:
 	void update_audio();
 	bool has_data() const;
 
+	f32 calculate_energy_level();
+
 	bool is_registered() const { return mic_registered; }
 	bool is_opened() const { return mic_opened; }
 	bool is_started() const { return mic_started; }