initial commit

companding/mulaw.h

@@ -0,0 +1,47 @@
+#pragma once
+#include <cstdint>
+
+namespace trnr::lib::companding {
+// mulaw companding based on code by Emilie Gillet / Mutable Instruments
+class mulaw {
+public:
+    int8_t encode_samples(int16_t pcm_val) {
+        int16_t mask;
+        int16_t seg;
+        uint8_t uval;
+        pcm_val = pcm_val >> 2;
+        if (pcm_val < 0) {
+            pcm_val = -pcm_val;
+            mask = 0x7f;
+        } else {
+            mask = 0xff;
+        }
+        if (pcm_val > 8159) pcm_val = 8159;
+        pcm_val += (0x84 >> 2);
+        
+        if (pcm_val <= 0x3f) seg = 0;
+        else if (pcm_val <= 0x7f) seg = 1;
+        else if (pcm_val <= 0xff) seg = 2;
+        else if (pcm_val <= 0x1ff) seg = 3;
+        else if (pcm_val <= 0x3ff) seg = 4;
+        else if (pcm_val <= 0x7ff) seg = 5;
+        else if (pcm_val <= 0xfff) seg = 6;
+        else if (pcm_val <= 0x1fff) seg = 7;
+        else seg = 8;
+        if (seg >= 8)
+            return static_cast<uint8_t>(0x7f ^ mask);
+        else {
+            uval = static_cast<uint8_t>((seg << 4) | ((pcm_val >> (seg + 1)) & 0x0f));
+            return (uval ^ mask);
+        }
+    }
+
+    int16_t decode_samples(uint8_t u_val) {
+        int16_t t;
+        u_val = ~u_val;
+        t = ((u_val & 0xf) << 3) + 0x84;
+        t <<= ((unsigned)u_val & 0x70) >> 4;
+        return ((u_val & 0x80) ? (0x84 - t) : (t - 0x84));
+    }
+};
+}

companding/ulaw.h

@@ -0,0 +1,93 @@
+#pragma once
+#include <stdlib.h>
+#include <cstdint>
+#include <cmath>
+
+namespace trnr::lib::companding {
+// ulaw compansion based on code by Chris Johnson
+class ulaw {
+public:
+    ulaw() {
+        fpd_l = 1.0; while (fpd_l < 16386) fpd_l = rand()*UINT32_MAX;
+        fpd_r = 1.0; while (fpd_r < 16386) fpd_r = rand()*UINT32_MAX;
+    }
+
+    void encode_samples(double& input_sample_l, double& input_sample_r) {
+
+        // ulaw encoding
+        static int noisesource_l = 0;
+        static int noisesource_r = 850010;
+        int residue;
+        double applyresidue;
+        
+        noisesource_l = noisesource_l % 1700021; noisesource_l++;
+        residue = noisesource_l * noisesource_l;
+        residue = residue % 170003; residue *= residue;
+        residue = residue % 17011; residue *= residue;
+        residue = residue % 1709; residue *= residue;
+        residue = residue % 173; residue *= residue;
+        residue = residue % 17;
+        applyresidue = residue;
+        applyresidue *= 0.00000001;
+        applyresidue *= 0.00000001;
+        input_sample_l += applyresidue;
+        if (input_sample_l<1.2e-38 && -input_sample_l<1.2e-38) {
+            input_sample_l -= applyresidue;
+        }
+        
+        noisesource_r = noisesource_r % 1700021; noisesource_r++;
+        residue = noisesource_r * noisesource_r;
+        residue = residue % 170003; residue *= residue;
+        residue = residue % 17011; residue *= residue;
+        residue = residue % 1709; residue *= residue;
+        residue = residue % 173; residue *= residue;
+        residue = residue % 17;
+        applyresidue = residue;
+        applyresidue *= 0.00000001;
+        applyresidue *= 0.00000001;
+        input_sample_r += applyresidue;
+        if (input_sample_r<1.2e-38 && -input_sample_r<1.2e-38) {
+            input_sample_r -= applyresidue;
+        }
+        
+        if (input_sample_l > 1.0) input_sample_l = 1.0;
+        if (input_sample_l < -1.0) input_sample_l = -1.0;
+        
+        if (input_sample_r > 1.0) input_sample_r = 1.0;
+        if (input_sample_r < -1.0) input_sample_r = -1.0;
+        
+        if (input_sample_l > 0) input_sample_l = log(1.0+(255*fabs(input_sample_l))) / log(256);
+        if (input_sample_l < 0) input_sample_l = -log(1.0+(255*fabs(input_sample_l))) / log(256);
+        
+        if (input_sample_r > 0) input_sample_r = log(1.0+(255*fabs(input_sample_r))) / log(256);
+        if (input_sample_r < 0) input_sample_r = -log(1.0+(255*fabs(input_sample_r))) / log(256);
+    }
+
+    void decode_samples(double& input_sample_l, double& input_sample_r) {
+
+        // ulaw decoding
+        if (fabs(input_sample_l)<1.18e-23) input_sample_l = fpd_l * 1.18e-17;
+        if (fabs(input_sample_r)<1.18e-23) input_sample_r = fpd_r * 1.18e-17;
+        
+        if (input_sample_l > 1.0) input_sample_l = 1.0;
+        if (input_sample_l < -1.0) input_sample_l = -1.0;
+        
+        if (input_sample_r > 1.0) input_sample_r = 1.0;
+        if (input_sample_r < -1.0) input_sample_r = -1.0;
+        
+        if (input_sample_l > 0) input_sample_l = (pow(256,fabs(input_sample_l))-1.0) / 255;
+        if (input_sample_l < 0) input_sample_l = -(pow(256,fabs(input_sample_l))-1.0) / 255;
+        
+        if (input_sample_r > 0) input_sample_r = (pow(256,fabs(input_sample_r))-1.0) / 255;
+        if (input_sample_r < 0) input_sample_r = -(pow(256,fabs(input_sample_r))-1.0) / 255;
+
+        // 64 bit stereo floating point dither
+        fpd_l ^= fpd_l << 13; fpd_l ^= fpd_l >> 17; fpd_l ^= fpd_l << 5;
+        fpd_r ^= fpd_r << 13; fpd_r ^= fpd_r >> 17; fpd_r ^= fpd_r << 5;
+    }
+
+private:
+    uint32_t fpd_l;
+	uint32_t fpd_r;
+};
+}