From 40311310d1a6d2fde2ee9f04bfa1f21ced7cbee2 Mon Sep 17 00:00:00 2001
From: Mary-nyan <mary@mary.zone>
Date: Tue, 6 Dec 2022 15:04:25 +0100
Subject: amadeus: Add missing compressor effect from REV11 (#4010)

* amadeus: Add missing compressor effect from REV11

This was in my reversing notes but seems I completely forgot to
implement it

Also took the opportunity to simplify the Limiter effect a bit.

* Remove some outdated comment

* Address gdkchan's comments
---
 .../Renderer/Dsp/State/CompressorState.cs          | 51 ++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 Ryujinx.Audio/Renderer/Dsp/State/CompressorState.cs

(limited to 'Ryujinx.Audio/Renderer/Dsp/State/CompressorState.cs')

diff --git a/Ryujinx.Audio/Renderer/Dsp/State/CompressorState.cs b/Ryujinx.Audio/Renderer/Dsp/State/CompressorState.cs
new file mode 100644
index 00000000..76aff807
--- /dev/null
+++ b/Ryujinx.Audio/Renderer/Dsp/State/CompressorState.cs
@@ -0,0 +1,51 @@
+using Ryujinx.Audio.Renderer.Dsp.Effect;
+using Ryujinx.Audio.Renderer.Parameter.Effect;
+
+namespace Ryujinx.Audio.Renderer.Dsp.State
+{
+    public class CompressorState
+    {
+        public ExponentialMovingAverage InputMovingAverage;
+        public float Unknown4;
+        public ExponentialMovingAverage CompressionGainAverage;
+        public float CompressorGainReduction;
+        public float Unknown10;
+        public float Unknown14;
+        public float PreviousCompressionEmaAlpha;
+        public float MakeupGain;
+        public float OutputGain;
+
+        public CompressorState(ref CompressorParameter parameter)
+        {
+            InputMovingAverage = new ExponentialMovingAverage(0.0f);
+            Unknown4 = 1.0f;
+            CompressionGainAverage = new ExponentialMovingAverage(1.0f);
+
+            UpdateParameter(ref parameter);
+        }
+
+        public void UpdateParameter(ref CompressorParameter parameter)
+        {
+            float threshold = parameter.Threshold;
+            float ratio = 1.0f / parameter.Ratio;
+            float attackCoefficient = parameter.AttackCoefficient;
+            float makeupGain;
+
+            if (parameter.MakeupGainEnabled)
+            {
+                makeupGain = (threshold * 0.5f * (ratio - 1.0f)) - 3.0f;
+            }
+            else
+            {
+                makeupGain = 0.0f;
+            }
+
+            PreviousCompressionEmaAlpha = attackCoefficient;
+            MakeupGain = makeupGain;
+            CompressorGainReduction = (1.0f - ratio) / Constants.ChannelCountMax;
+            Unknown10 = threshold - 1.5f;
+            Unknown14 = threshold + 1.5f;
+            OutputGain = FloatingPointHelper.DecibelToLinearExtended(parameter.OutputGain + makeupGain);
+        }
+    }
+}
-- 
cgit v1.2.3