[audio_core/hid] Audio REV12+15 support + HID fixes (#2719)

This fixes newer updates / games.

Implements partial audio rev15, rev13, rev12 and HID issues on SDK20+ games.

Credits to LotP (Ryubing) and Zephyron (Citron) for their research and implementation.

Co-authored-by: Zephyron <zephyron@citron-emu.org>
Co-authored-by: Shinmegumi <shinmegumi@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2719
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Co-authored-by: unknown <sahyno1996@gmail.com>
Co-committed-by: unknown <sahyno1996@gmail.com>

4 files changed, 81 insertions, 4 deletions

diff --git a/src/audio_core/renderer/command/effect/biquad_filter.cpp b/src/audio_core/renderer/command/effect/biquad_filter.cpp
index 539e0c6370..4ad3184079 100644
--- a/src/audio_core/renderer/command/effect/biquad_filter.cpp
+++ b/src/audio_core/renderer/command/effect/biquad_filter.cpp
@@ -52,6 +52,40 @@ void ApplyBiquadFilterFloat(std::span<s32> output, std::span<const s32> input,
 }
 
 /**
+ * Biquad filter float implementation with native float coefficients.
+ */
+void ApplyBiquadFilterFloat2(std::span<s32> output, std::span<const s32> input,
+                             std::array<f32, 3>& b, std::array<f32, 2>& a,
+                             VoiceState::BiquadFilterState& state, const u32 sample_count) {
+    constexpr f64 min{std::numeric_limits<s32>::min()};
+    constexpr f64 max{std::numeric_limits<s32>::max()};
+
+    std::array<f64, 3> b_double{static_cast<f64>(b[0]), static_cast<f64>(b[1]),
+                                static_cast<f64>(b[2])};
+    std::array<f64, 2> a_double{static_cast<f64>(a[0]), static_cast<f64>(a[1])};
+    std::array<f64, 4> s{Common::BitCast<f64>(state.s0), Common::BitCast<f64>(state.s1),
+                         Common::BitCast<f64>(state.s2), Common::BitCast<f64>(state.s3)};
+
+    for (u32 i = 0; i < sample_count; i++) {
+        f64 in_sample{static_cast<f64>(input[i])};
+        auto sample{in_sample * b_double[0] + s[0] * b_double[1] + s[1] * b_double[2] +
+                    s[2] * a_double[0] + s[3] * a_double[1]};
+
+        output[i] = static_cast<s32>(std::clamp(sample, min, max));
+
+        s[1] = s[0];
+        s[0] = in_sample;
+        s[3] = s[2];
+        s[2] = sample;
+    }
+
+    state.s0 = Common::BitCast<s64>(s[0]);
+    state.s1 = Common::BitCast<s64>(s[1]);
+    state.s2 = Common::BitCast<s64>(s[2]);
+    state.s3 = Common::BitCast<s64>(s[3]);
+}
+
+/**
  * Biquad filter s32 implementation.
  *
  * @param output       - Output container for filtered samples.
@@ -98,8 +132,14 @@ void BiquadFilterCommand::Process(const AudioRenderer::CommandListProcessor& pro
         processor.mix_buffers.subspan(output * processor.sample_count, processor.sample_count)};
 
     if (use_float_processing) {
-        ApplyBiquadFilterFloat(output_buffer, input_buffer, biquad.b, biquad.a, *state_,
-                               processor.sample_count);
+        // REV15+: Use native float coefficients if available
+        if (use_float_coefficients) {
+            ApplyBiquadFilterFloat2(output_buffer, input_buffer, biquad_float.numerator,
+                                    biquad_float.denominator, *state_, processor.sample_count);
+        } else {
+            ApplyBiquadFilterFloat(output_buffer, input_buffer, biquad.b, biquad.a, *state_,
+                                   processor.sample_count);
+        }
     } else {
         ApplyBiquadFilterInt(output_buffer, input_buffer, biquad.b, biquad.a, *state_,
                              processor.sample_count);
diff --git a/src/audio_core/renderer/command/effect/biquad_filter.h b/src/audio_core/renderer/command/effect/biquad_filter.h
index 0e903930a6..0e1893e536 100644
--- a/src/audio_core/renderer/command/effect/biquad_filter.h
+++ b/src/audio_core/renderer/command/effect/biquad_filter.h
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -50,12 +53,16 @@ struct BiquadFilterCommand : ICommand {
     s16 output;
     /// Input parameters for biquad
     VoiceInfo::BiquadFilterParameter biquad;
+    /// Input parameters for biquad (REV15+ native float)
+    VoiceInfo::BiquadFilterParameter2 biquad_float;
     /// Biquad state, updated each call
     CpuAddr state;
     /// If true, reset the state
     bool needs_init;
     /// If true, use float processing rather than int
     bool use_float_processing;
+    /// If true, use native float coefficients (REV15+)
+    bool use_float_coefficients;
 };
 
 /**
@@ -72,4 +79,18 @@ void ApplyBiquadFilterFloat(std::span<s32> output, std::span<const s32> input,
                             std::array<s16, 3>& b, std::array<s16, 2>& a,
                             VoiceState::BiquadFilterState& state, const u32 sample_count);
 
+/**
+ * Biquad filter float implementation with native float coefficients (SDK REV15+).
+ *
+ * @param output       - Output container for filtered samples.
+ * @param input        - Input container for samples to be filtered.
+ * @param b            - Feedforward coefficients (float).
+ * @param a            - Feedback coefficients (float).
+ * @param state        - State to track previous samples.
+ * @param sample_count - Number of samples to process.
+ */
+void ApplyBiquadFilterFloat2(std::span<s32> output, std::span<const s32> input,
+                             std::array<f32, 3>& b, std::array<f32, 2>& a,
+                             VoiceState::BiquadFilterState& state, const u32 sample_count);
+
 } // namespace AudioCore::Renderer
diff --git a/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.cpp b/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.cpp
index 208bbeaf29..2dfbcf6145 100644
--- a/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.cpp
+++ b/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.cpp
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -33,8 +36,14 @@ void MultiTapBiquadFilterCommand::Process(const AudioRenderer::CommandListProces
             *state = {};
         }
 
-        ApplyBiquadFilterFloat(output_buffer, input_buffer, biquads[i].b, biquads[i].a, *state,
-                               processor.sample_count);
+        // REV15+: Use native float coefficients if available
+        if (use_float_coefficients) {
+            ApplyBiquadFilterFloat2(output_buffer, input_buffer, biquads_float[i].numerator,
+                                    biquads_float[i].denominator, *state, processor.sample_count);
+        } else {
+            ApplyBiquadFilterFloat(output_buffer, input_buffer, biquads[i].b, biquads[i].a, *state,
+                                   processor.sample_count);
+        }
     }
 }
 
diff --git a/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.h b/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.h
index 50fce80b0c..35fa76f62d 100644
--- a/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.h
+++ b/src/audio_core/renderer/command/effect/multi_tap_biquad_filter.h
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -49,12 +52,16 @@ struct MultiTapBiquadFilterCommand : ICommand {
     s16 output;
     /// Biquad parameters
     std::array<VoiceInfo::BiquadFilterParameter, MaxBiquadFilters> biquads;
+    /// Biquad parameters (REV15+ native float)
+    std::array<VoiceInfo::BiquadFilterParameter2, MaxBiquadFilters> biquads_float;
     /// Biquad states, updated each call
     std::array<CpuAddr, MaxBiquadFilters> states;
     /// If each biquad needs initialisation
     std::array<bool, MaxBiquadFilters> needs_init;
     /// Number of active biquads
     u8 filter_tap_count;
+    /// If true, use native float coefficients (REV15+)
+    bool use_float_coefficients;
 };
 
 } // namespace AudioCore::Renderer