Create libretro-common/include/filters.h

audio/drivers_resampler/sinc.c

@@ -25,6 +25,7 @@
 #endif
 
 #include <retro_inline.h>
+#include <filters.h>
 #include <memalign.h>
 
 #include "../audio_resampler_driver.h"
@@ -116,43 +117,9 @@ typedef struct rarch_sinc_resampler
    float *main_buffer;
 } rarch_sinc_resampler_t;
 
-static INLINE double sinc(double val)
-{
-   if (fabs(val) < 0.00001)
-      return 1.0;
-   return sin(val) / val;
-}
-
 #if defined(SINC_WINDOW_LANCZOS)
 #define window_function(idx)  (sinc(M_PI * (idx)))
 #elif defined(SINC_WINDOW_KAISER)
-/* Modified Bessel function of first order.
- * Check Wiki for mathematical definition ... */
-static INLINE double besseli0(double x)
-{
-   unsigned i;
-   double sum            = 0.0;
-   double factorial      = 1.0;
-   double factorial_mult = 0.0;
-   double x_pow          = 1.0;
-   double two_div_pow    = 1.0;
-   double x_sqr          = x * x;
-
-   /* Approximate. This is an infinite sum.
-    * Luckily, it converges rather fast. */
-   for (i = 0; i < 18; i++)
-   {
-      sum += x_pow * two_div_pow / (factorial * factorial);
-
-      factorial_mult += 1.0;
-      x_pow *= x_sqr;
-      two_div_pow *= 0.25;
-      factorial *= factorial_mult;
-   }
-
-   return sum;
-}
-
 #define window_function(idx) (besseli0(SINC_WINDOW_KAISER_BETA * sqrt(1 - (idx) * (idx))))
 #else
 #error "No SINC window function defined."

libretro-common/gfx/scaler/scaler_filter.c

@@ -20,16 +20,19 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+
 #include <gfx/scaler/filter.h>
 #include <gfx/scaler/scaler_int.h>
 #include <retro_miscellaneous.h>
-#include <math.h>
+#include <retro_inline.h>
+#include <filters.h>
+
 #ifndef M_PI
 #define M_PI 3.14159265358979323846
 #endif
-#include <stdio.h>
-#include <string.h>
-#include <retro_inline.h>
 
 static bool allocate_filters(struct scaler_ctx *ctx)
 {
@@ -113,13 +116,6 @@ static bool gen_filter_bilinear(struct scaler_ctx *ctx)
    return true;
 }
 
-static INLINE double filter_sinc(double phase)
-{
-   if (fabs(phase) < 0.0001)
-      return 1.0;
-   return sin(phase) / phase;
-}
-
 static void gen_filter_sinc_sub(struct scaler_filter *filter,
       int len, int pos, int step, double phase_mul)
 {
@@ -134,7 +130,7 @@ static void gen_filter_sinc_sub(struct scaler_filter *filter,
       {
          double sinc_phase    = M_PI * ((double)((sinc_size << 15) + (pos & 0xffff)) / 0x10000 - j);
          double lanczos_phase = sinc_phase / ((sinc_size >> 1));
-         int16_t sinc_val     = FILTER_UNITY * filter_sinc(sinc_phase * phase_mul) * filter_sinc(lanczos_phase) * phase_mul;
+         int16_t sinc_val     = FILTER_UNITY * sinc(sinc_phase * phase_mul) * sinc(lanczos_phase) * phase_mul;
 
          filter->filter[i * sinc_size + j] = sinc_val;
       }
@@ -172,7 +168,6 @@ static bool gen_filter_sinc(struct scaler_ctx *ctx)
    return true;
 }
 
-
 static bool validate_filter(struct scaler_ctx *ctx)
 {
    int i;

libretro-common/include/filters.h

@@ -0,0 +1,63 @@
+/* Copyright  (C) 2010-2015 The RetroArch team
+ *
+ * ---------------------------------------------------------------------------------------
+ * The following license statement only applies to this file (filters.h).
+ * ---------------------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge,
+ * to any person obtaining a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _LIBRETRO_SDK_FILTERS_H
+#define _LIBRETRO_SDK_FILTERS_H
+
+#include <math.h>
+#include <retro_inline.h>
+
+static INLINE double sinc(double val)
+{
+   if (fabs(val) < 0.00001)
+      return 1.0;
+   return sin(val) / val;
+}
+
+/* Modified Bessel function of first order.
+ * Check Wiki for mathematical definition ... */
+static INLINE double besseli0(double x)
+{
+   unsigned i;
+   double sum            = 0.0;
+   double factorial      = 1.0;
+   double factorial_mult = 0.0;
+   double x_pow          = 1.0;
+   double two_div_pow    = 1.0;
+   double x_sqr          = x * x;
+
+   /* Approximate. This is an infinite sum.
+    * Luckily, it converges rather fast. */
+   for (i = 0; i < 18; i++)
+   {
+      sum += x_pow * two_div_pow / (factorial * factorial);
+
+      factorial_mult += 1.0;
+      x_pow *= x_sqr;
+      two_div_pow *= 0.25;
+      factorial *= factorial_mult;
+   }
+
+   return sum;
+}
+
+#endif