1 files changed, 74 insertions, 0 deletions
diff --git a/src/audio_core/renderer/command/effect/biquad_filter.h b/src/audio_core/renderer/command/effect/biquad_filter.h
new file mode 100644
index 000000000..4c9c42d29
--- /dev/null
+++ b/src/audio_core/renderer/command/effect/biquad_filter.h
@@ -0,0 +1,74 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string>
+
+#include "audio_core/renderer/command/icommand.h"
+#include "audio_core/renderer/voice/voice_info.h"
+#include "audio_core/renderer/voice/voice_state.h"
+#include "common/common_types.h"
+
+namespace AudioCore::AudioRenderer {
+namespace ADSP {
+class CommandListProcessor;
+}
+
+/**
+ * AudioRenderer command for applying a biquad filter to the input mix buffer, saving the results to
+ * the output mix buffer.
+ */
+struct BiquadFilterCommand : ICommand {
+    /**
+     * Print this command's information to a string.
+     *
+     * @param processor - The CommandListProcessor processing this command.
+     * @param string    - The string to print into.
+     */
+    void Dump(const ADSP::CommandListProcessor& processor, std::string& string) override;
+
+    /**
+     * Process this command.
+     *
+     * @param processor - The CommandListProcessor processing this command.
+     */
+    void Process(const ADSP::CommandListProcessor& processor) override;
+
+    /**
+     * Verify this command's data is valid.
+     *
+     * @param processor - The CommandListProcessor processing this command.
+     * @return True if the command is valid, otherwise false.
+     */
+    bool Verify(const ADSP::CommandListProcessor& processor) override;
+
+    /// Input mix buffer index
+    s16 input;
+    /// Output mix buffer index
+    s16 output;
+    /// Input parameters for biquad
+    VoiceInfo::BiquadFilterParameter biquad;
+    /// 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;
+};
+
+/**
+ * Biquad filter float implementation.
+ *
+ * @param output       - Output container for filtered samples.
+ * @param input        - Input container for samples to be filtered.
+ * @param b            - Feedforward coefficients.
+ * @param a            - Feedback coefficients.
+ * @param state        - State to track previous samples.
+ * @param sample_count - Number of samples to process.
+ */
+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);
+
+} // namespace AudioCore::AudioRenderer