1 files changed, 57 insertions, 0 deletions
diff --git a/Alc/mastering.h b/Alc/mastering.h
new file mode 100644
index 00000000..0a7b4901
--- /dev/null
+++ b/Alc/mastering.h
@@ -0,0 +1,57 @@
+#ifndef MASTERING_H
+#define MASTERING_H
+
+#include "AL/al.h"
+
+/* For BUFFERSIZE. */
+#include "alMain.h"
+
+typedef struct Compressor {
+    ALfloat PreGain;
+    ALfloat PostGain;
+    ALboolean SummedLink;
+    ALfloat AttackMin;
+    ALfloat AttackMax;
+    ALfloat ReleaseMin;
+    ALfloat ReleaseMax;
+    ALfloat Ratio;
+    ALfloat Threshold;
+    ALfloat Knee;
+    ALuint SampleRate;
+
+    ALuint RmsSum;
+    ALuint *RmsWindow;
+    ALsizei RmsIndex;
+    ALfloat Envelope[BUFFERSIZE];
+    ALfloat EnvLast;
+} Compressor;
+
+/* The compressor requires the following information for proper
+ * initialization:
+ *
+ *   PreGainDb      - Gain applied before detection (in dB).
+ *   PostGainDb     - Gain applied after compression (in dB).
+ *   SummedLink     - Whether to use summed (true) or maxed (false) linking.
+ *   RmsSensing     - Whether to use RMS (true) or Peak (false) sensing.
+ *   AttackTimeMin  - Minimum attack time (in seconds).
+ *   AttackTimeMax  - Maximum attack time.  Automates when min != max.
+ *   ReleaseTimeMin - Minimum release time (in seconds).
+ *   ReleaseTimeMax - Maximum release time.  Automates when min != max.
+ *   Ratio          - Compression ratio (x:1).  Set to 0 for true limiter.
+ *   ThresholdDb    - Triggering threshold (in dB).
+ *   KneeDb         - Knee width (below threshold; in dB).
+ *   SampleRate     - Sample rate to process.
+ */
+Compressor *CompressorInit(const ALfloat PreGainDb, const ALfloat PostGainDb,
+    const ALboolean SummedLink, const ALboolean RmsSensing, const ALfloat AttackTimeMin,
+    const ALfloat AttackTimeMax, const ALfloat ReleaseTimeMin, const ALfloat ReleaseTimeMax,
+    const ALfloat Ratio, const ALfloat ThresholdDb, const ALfloat KneeDb,
+    const ALuint SampleRate);
+
+void ApplyCompression(struct Compressor *Comp, const ALsizei NumChans, const ALsizei SamplesToDo,
+                      ALfloat (*restrict OutBuffer)[BUFFERSIZE]);
+
+inline ALuint GetCompressorSampleRate(const Compressor *Comp)
+{ return Comp->SampleRate; }
+
+#endif /* MASTERING_H */