1 files changed, 56 insertions, 0 deletions
diff --git a/dnn/common.h b/dnn/common.h
new file mode 100644
index 00000000..b3bec730
--- /dev/null
+++ b/dnn/common.h
@@ -0,0 +1,56 @@
+
+
+#ifndef COMMON_H
+#define COMMON_H
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "opus_defines.h"
+
+#define LOG256 5.5451774445f
+static OPUS_INLINE float log2_approx(float x)
+{
+   int integer;
+   float frac;
+   union {
+      float f;
+      int i;
+   } in;
+   in.f = x;
+   integer = (in.i>>23)-127;
+   in.i -= integer<<23;
+   frac = in.f - 1.5f;
+   frac = -0.41445418f + frac*(0.95909232f
+          + frac*(-0.33951290f + frac*0.16541097f));
+   return 1+integer+frac;
+}
+
+#define log_approx(x) (0.69315f*log2_approx(x))
+
+static OPUS_INLINE float ulaw2lin(float u)
+{
+    float s;
+    float scale_1 = 32768.f/255.f;
+    u = u - 128.f;
+    s = u >= 0.f ? 1.f : -1.f;
+    u = fabs(u);
+    return s*scale_1*(exp(u/128.*LOG256)-1);
+}
+
+static OPUS_INLINE int lin2ulaw(float x)
+{
+    float u;
+    float scale = 255.f/32768.f;
+    int s = x >= 0 ? 1 : -1;
+    x = fabs(x);
+    u = (s*(128*log_approx(1+scale*x)/LOG256));
+    u = 128 + u;
+    if (u < 0) u = 0;
+    if (u > 255) u = 255;
+    return (int)floor(.5 + u);
+}
+
+
+
+#endif