feat: REV15 audio renderer + HID fix (v0.8.0)

Complete SDK15 audio implementation with native float biquads.
Fixes TotK 1.4.2 and BotW 1.8.2 boot loops.

- Add REV15 float biquad filter support
- Implement VoiceInParameterV2 (0x188 bytes)
- Add SplitterDestinationV2b with biquad filters
- Fix HID sampling number (double state value)
- Add AudioSnoopManager and AudioSystemManager
- Implement FinalOutputRecorder system
- Add FFT and loudness calculator (ITU-R BS.1770)
- Add full Limiter effect

Resolves boot loops and controller detection in SDK20 games.

Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/audio_core/renderer/effect/limiter.cpp

@@ -0,0 +1,67 @@
+// SPDX-FileCopyrightText: Copyright 2025 Citron Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "audio_core/renderer/effect/limiter.h"
+#include "core/hle/result.h"
+
+namespace AudioCore::Renderer {
+
+void LimiterInfo::Update(BehaviorInfo::ErrorInfo& error_info,
+                          const EffectInfoBase::InParameterVersion1& in_params,
+                          const PoolMapper& pool_mapper) {
+    auto in_specific{reinterpret_cast<const ParameterVersion1*>(in_params.specific.data())};
+    auto params{reinterpret_cast<ParameterVersion1*>(parameter.data())};
+
+    std::memcpy(params, in_specific, sizeof(ParameterVersion1));
+    mix_id = in_params.mix_id;
+    process_order = in_params.process_order;
+    enabled = in_params.enabled;
+
+    error_info.error_code = ResultSuccess;
+    error_info.address = CpuAddr(0);
+}
+
+void LimiterInfo::Update(BehaviorInfo::ErrorInfo& error_info,
+                          const EffectInfoBase::InParameterVersion2& in_params,
+                          const PoolMapper& pool_mapper) {
+    auto in_specific{reinterpret_cast<const ParameterVersion2*>(in_params.specific.data())};
+    auto params{reinterpret_cast<ParameterVersion2*>(parameter.data())};
+
+    std::memcpy(params, in_specific, sizeof(ParameterVersion2));
+    mix_id = in_params.mix_id;
+    process_order = in_params.process_order;
+    enabled = in_params.enabled;
+
+    error_info.error_code = ResultSuccess;
+    error_info.address = CpuAddr(0);
+}
+
+void LimiterInfo::UpdateForCommandGeneration() {
+    if (enabled) {
+        usage_state = UsageState::Enabled;
+    } else {
+        usage_state = UsageState::Disabled;
+    }
+
+    auto params{reinterpret_cast<ParameterVersion1*>(parameter.data())};
+    params->state = ParameterState::Updated;
+}
+
+void LimiterInfo::InitializeResultState(EffectResultState& result_state) {
+    auto limiter_state{reinterpret_cast<State*>(result_state.state.data())};
+    limiter_state->envelope = 1.0f;
+    limiter_state->gain_reduction = 1.0f;
+    limiter_state->peak_hold = 0.0f;
+    limiter_state->peak_hold_count = 0;
+    limiter_state->channel_peaks.fill(0.0f);
+}
+
+void LimiterInfo::UpdateResultState(EffectResultState& cpu_state, EffectResultState& dsp_state) {
+    cpu_state = dsp_state;
+}
+
+CpuAddr LimiterInfo::GetWorkbuffer(s32 index) {
+    return GetSingleBuffer(index);
+}
+
+} // namespace AudioCore::Renderer

src/audio_core/renderer/effect/limiter.h

@@ -0,0 +1,101 @@
+// SPDX-FileCopyrightText: Copyright 2025 Citron Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <array>
+
+#include "audio_core/common/common.h"
+#include "audio_core/renderer/effect/effect_info_base.h"
+#include "common/common_types.h"
+
+namespace AudioCore::Renderer {
+
+/**
+ * A full-featured limiter effect with attack, release, and threshold controls.
+ * More sophisticated than LightLimiter.
+ */
+class LimiterInfo : public EffectInfoBase {
+public:
+    struct ParameterVersion1 {
+        /* 0x00 */ std::array<s8, MaxChannels> inputs;
+        /* 0x06 */ std::array<s8, MaxChannels> outputs;
+        /* 0x0C */ u16 channel_count;
+        /* 0x0E */ u16 padding;
+        /* 0x10 */ s32 sample_rate;
+        /* 0x14 */ f32 attack_time;    // Attack time in milliseconds
+        /* 0x18 */ f32 release_time;   // Release time in milliseconds
+        /* 0x1C */ f32 threshold;      // Threshold in dB
+        /* 0x20 */ f32 makeup_gain;    // Makeup gain in dB
+        /* 0x24 */ f32 ratio;          // Compression ratio
+        /* 0x28 */ ParameterState state;
+        /* 0x29 */ bool is_enabled;
+        /* 0x2A */ char unk2A[0x2];
+    };
+    static_assert(sizeof(ParameterVersion1) <= sizeof(EffectInfoBase::InParameterVersion1),
+                  "LimiterInfo::ParameterVersion1 has the wrong size!");
+
+    using ParameterVersion2 = ParameterVersion1;
+
+    struct State {
+        /* 0x00 */ f32 envelope;
+        /* 0x04 */ f32 gain_reduction;
+        /* 0x08 */ f32 peak_hold;
+        /* 0x0C */ u32 peak_hold_count;
+        /* 0x10 */ std::array<f32, MaxChannels> channel_peaks;
+    };
+    static_assert(sizeof(State) <= sizeof(EffectInfoBase::State),
+                  "LimiterInfo::State is too large!");
+
+    /**
+     * Update the info with new parameters.
+     *
+     * @param error_info - Output error information.
+     * @param in_params - Input parameters.
+     * @param pool_mapper - Memory pool mapper for buffers.
+     */
+    void Update(BehaviorInfo::ErrorInfo& error_info,
+                const EffectInfoBase::InParameterVersion1& in_params,
+                const PoolMapper& pool_mapper);
+
+    /**
+     * Update the info with new parameters (version 2).
+     *
+     * @param error_info - Output error information.
+     * @param in_params - Input parameters.
+     * @param pool_mapper - Memory pool mapper for buffers.
+     */
+    void Update(BehaviorInfo::ErrorInfo& error_info,
+                const EffectInfoBase::InParameterVersion2& in_params,
+                const PoolMapper& pool_mapper);
+
+    /**
+     * Update the usage state for command generation.
+     */
+    void UpdateForCommandGeneration();
+
+    /**
+     * Initialize the result state.
+     *
+     * @param result_state - Result state to initialize.
+     */
+    void InitializeResultState(EffectResultState& result_state);
+
+    /**
+     * Update the result state.
+     *
+     * @param cpu_state - CPU-side result state.
+     * @param dsp_state - DSP-side result state.
+     */
+    void UpdateResultState(EffectResultState& cpu_state, EffectResultState& dsp_state);
+
+    /**
+     * Get a workbuffer address.
+     *
+     * @param index - Index of the workbuffer.
+     * @return Address of the workbuffer.
+     */
+    CpuAddr GetWorkbuffer(s32 index);
+};
+
+} // namespace AudioCore::Renderer