Release 1.0.20

* Optimization of compressor and gate functions using AVX-512 instruction set.
* Introduced SIMD-optimized expander curve and gain functions.
* Improved performance of logarithm values calculations.
* Fixed Mid/Side conversion functions for AArch64 architecture (contributed by
  marcan at GitHub).
* Updated build scripts.
* Updated module versions in dependencies.

Author: sadko4u

CHANGELOG

@@ -2,6 +2,15 @@
 * RECENT CHANGES
 *******************************************************************************
 
+=== 1.0.20 ===
+* Optimization of compressor and gate functions using AVX-512 instruction set.
+* Introduced SIMD-optimized expander curve and gain functions.
+* Improved performance of logarithm values calculations.
+* Fixed Mid/Side conversion functions for AArch64 architecture (contributed by
+  marcan at GitHub).
+* Updated build scripts.
+* Updated module versions in dependencies.
+
 === 1.0.19 ===
 * AVX2 optimization of search functions for maximum and minimum.
 * Implemented SIMD-optimized gate functions.

include/lsp-plug.in/dsp/common/dynamics.h

@@ -26,6 +26,7 @@
 
 #include <lsp-plug.in/dsp/common/dynamics/types.h>
 #include <lsp-plug.in/dsp/common/dynamics/compressor.h>
+#include <lsp-plug.in/dsp/common/dynamics/expander.h>
 #include <lsp-plug.in/dsp/common/dynamics/gate.h>
 
 

include/lsp-plug.in/dsp/common/dynamics/expander.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2023 Linux Studio Plugins Project <https://lsp-plug.in/>
+ *           (C) 2023 Vladimir Sadovnikov <sadko4u@gmail.com>
+ *
+ * This file is part of lsp-dsp-lib
+ * Created on: 1 нояб. 2023 г.
+ *
+ * lsp-dsp-lib is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * lsp-dsp-lib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with lsp-dsp-lib. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef LSP_PLUG_IN_DSP_COMMON_DYNAMICS_EXPANDER_H_
+#define LSP_PLUG_IN_DSP_COMMON_DYNAMICS_EXPANDER_H_
+
+#include <lsp-plug.in/dsp/common/types.h>
+#include <lsp-plug.in/dsp/common/dynamics/types.h>
+
+LSP_DSP_LIB_SYMBOL(void, uexpander_x1_gain, float *dst, const float *src, const LSP_DSP_LIB_TYPE(expander_knee_t) *c, size_t count);
+LSP_DSP_LIB_SYMBOL(void, dexpander_x1_gain, float *dst, const float *src, const LSP_DSP_LIB_TYPE(expander_knee_t) *c, size_t count);
+
+LSP_DSP_LIB_SYMBOL(void, uexpander_x1_curve, float *dst, const float *src, const LSP_DSP_LIB_TYPE(expander_knee_t) *c, size_t count);
+LSP_DSP_LIB_SYMBOL(void, dexpander_x1_curve, float *dst, const float *src, const LSP_DSP_LIB_TYPE(expander_knee_t) *c, size_t count);
+
+
+#endif /* LSP_PLUG_IN_DSP_COMMON_DYNAMICS_EXPANDER_H_ */

include/lsp-plug.in/dsp/common/dynamics/types.h

@@ -85,6 +85,41 @@ typedef struct LSP_DSP_LIB_TYPE(gate_knee_t)
     float       herm[4];        // Hermite interpolation of the knee with the 3rd-order polynom
 } LSP_DSP_LIB_TYPE(gate_knee_t);
 
+/**
+ * Gate knee is a curve that consists of three parts:
+ *   1. Part with constant gain amplification
+ *   2. Soft compression knee
+ *   3. Gain reduction part
+ *
+ * The order of these parts can be direct for upward expander and reverse for downward expander.
+ *
+ * The typical algorithm of computing the expander's curve:
+ *   a. for upward expander:
+ *     1. Take absolute value of the sample: x = fabfs(in)
+ *     2. If x >= threshold then assume x = threshold
+ *     3. If x <= start then return x
+ *     4. Compute the natural logarithm of the x: lx = logf(x).
+ *     5. If x < end then compute the gain using the 2nd-order polynom: gain = (herm[0]*lx + herm[1])*lx + herm[2]
+ *     6. Otherwise compute the gain using the 1st-order polynom: gain = tilt[0]*lx + tilt[1]
+ *     7. return expf(gain)
+ *   b. for downward expander:
+ *     1. Take absolute value of the sample: x = fabfs(in)
+ *     2. If x < threshold then return 0.
+ *     3. If x >= end then return x
+ *     4. Compute the natural logarithm of the x: lx = logf(x).
+ *     5. If x > start then compute the gain using the 2nd-order polynom: gain = (herm[0]*lx + herm[1])*lx + herm[2]
+ *     6. Otherwise compute the gain using the 1st-order polynom: gain = tilt[0]*lx + tilt[1]
+ *     7. return expf(gain)
+ */
+typedef struct LSP_DSP_LIB_TYPE(expander_knee_t)
+{
+    float       start;          // The start of the knee, in gain units
+    float       end;            // The end of the knee, in gain units
+    float       threshold;      // The threshold to limit the expander effect and prevent from +Inf/-Inf values
+    float       herm[3];        // Hermite interpolation of the knee with the 2nd-order polynom
+    float       tilt[2];        // Tilt interpolation
+} LSP_DSP_LIB_TYPE(expander_knee_t);
+
 #pragma pack(pop)
 
 LSP_DSP_LIB_END_NAMESPACE

include/lsp-plug.in/dsp/version.h

@@ -25,7 +25,7 @@
 // Define version of headers
 #define LSP_DSP_LIB_MAJOR           1
 #define LSP_DSP_LIB_MINOR           0
-#define LSP_DSP_LIB_MICRO           19
+#define LSP_DSP_LIB_MICRO           20
 
 #if defined(__WINDOWS__) || defined(__WIN32__) || defined(__WIN64__) || defined(_WIN64) || defined(_WIN32) || defined(__WINNT) || defined(__WINNT__)
     #define LSP_DSP_LIB_EXPORT_MODIFIER     __declspec(dllexport)

include/private/dsp/arch/aarch64/asimd/dynamics.h

@@ -27,6 +27,7 @@
 #endif /* PRIVATE_DSP_ARCH_AARCH64_ASIMD_IMPL */
 
 #include <private/dsp/arch/aarch64/asimd/dynamics/compressor.h>
+#include <private/dsp/arch/aarch64/asimd/dynamics/expander.h>
 #include <private/dsp/arch/aarch64/asimd/dynamics/gate.h>
 
 #endif /* PRIVATE_DSP_ARCH_AARCH64_ASIMD_DYNAMICS_H_ */

include/private/dsp/arch/aarch64/asimd/dynamics/compressor.h

@@ -22,6 +22,10 @@
 #ifndef PRIVATE_DSP_ARCH_AARCH64_ASIMD_DYNAMICS_COMPRESSOR_H_
 #define PRIVATE_DSP_ARCH_AARCH64_ASIMD_DYNAMICS_COMPRESSOR_H_
 
+#ifndef PRIVATE_DSP_ARCH_AARCH64_ASIMD_IMPL
+    #error "This header should not be included directly"
+#endif /* PRIVATE_DSP_ARCH_AARCH64_ASIMD_IMPL */
+
 #include <private/dsp/arch/aarch64/asimd/pmath/exp.h>
 #include <private/dsp/arch/aarch64/asimd/pmath/log.h>
 
@@ -126,6 +130,7 @@ namespace lsp
 
     #define PROCESS_COMP_FULL_X4 \
         /* in: q0 = x0, q1 = x1 */ \
+        __ASM_EMIT("fabs                v0.4s, v0.4s")                      /* v0  = fabsf(x0) */ \
         __ASM_EMIT("str                 q0, [%[mem], #0x00]")               /* mem[0x00] = fabfs(x0) */ \
         LOGE_CORE_X4                                                        /* v0= lx0 = logf(fabsf(x0)) */ \
         __ASM_EMIT("str                 q0, [%[mem], #0x20]")               /* mem[0x20] = lx0 */ \