Begin implementing EQ.

audio/fft/fft.c

@@ -18,7 +18,7 @@
 #include <stdlib.h>
 
 #ifndef M_PI
-#define M_PI 3.14159265
+#define M_PI 3.1415926535897932384626433832795
 #endif
 
 struct rarch_fft
@@ -126,42 +126,11 @@ void rarch_fft_free(rarch_fft_t *fft)
    free(fft);
 }
 
-static inline rarch_fft_complex_t complex_mul(rarch_fft_complex_t a, rarch_fft_complex_t b)
-{
-   rarch_fft_complex_t out = {
-      a.real * b.real - a.imag * b.imag,
-      a.imag * b.real + a.real * b.imag,
-   };
-
-   return out;
-}
-
-static inline rarch_fft_complex_t complex_add(rarch_fft_complex_t a, rarch_fft_complex_t b)
-{
-   rarch_fft_complex_t out = {
-      a.real + b.real,
-      a.imag + b.imag,
-   };
-
-   return out;
-}
-
-static inline rarch_fft_complex_t complex_sub(rarch_fft_complex_t a, rarch_fft_complex_t b)
-{
-   rarch_fft_complex_t out = {
-      a.real - b.real,
-      a.imag - b.imag,
-   };
-
-   return out;
-}
-
-
 static void butterfly(rarch_fft_complex_t *a, rarch_fft_complex_t *b, rarch_fft_complex_t mod)
 {
-   mod = complex_mul(mod, *b);
-   *b = complex_sub(*a, mod);
-   *a = complex_add(*a, mod);
+   mod = rarch_fft_complex_mul(mod, *b);
+   *b = rarch_fft_complex_sub(*a, mod);
+   *a = rarch_fft_complex_add(*a, mod);
 }
 
 static void butterflies(rarch_fft_complex_t *butterfly_buf,
@@ -221,6 +190,6 @@ void rarch_fft_process_inverse(rarch_fft_t *fft,
             1, step_size, samples);
    }
 
-   resolve_float(out, fft->interleave_buffer, fft->size, 1.0f / fft->size);
+   resolve_float(out, fft->interleave_buffer, samples, 1.0f / samples);
 }
 

audio/fft/fft.h

@@ -25,6 +25,51 @@ typedef struct
    float imag;
 } rarch_fft_complex_t;
 
+static inline rarch_fft_complex_t rarch_fft_complex_mul(rarch_fft_complex_t a,
+      rarch_fft_complex_t b)
+{
+   rarch_fft_complex_t out = {
+      a.real * b.real - a.imag * b.imag,
+      a.imag * b.real + a.real * b.imag,
+   };
+
+   return out;
+
+}
+
+static inline rarch_fft_complex_t rarch_fft_complex_add(rarch_fft_complex_t a,
+      rarch_fft_complex_t b)
+{
+   rarch_fft_complex_t out = {
+      a.real + b.real,
+      a.imag + b.imag,
+   };
+
+   return out;
+
+}
+
+static inline rarch_fft_complex_t rarch_fft_complex_sub(rarch_fft_complex_t a,
+      rarch_fft_complex_t b)
+{
+   rarch_fft_complex_t out = {
+      a.real - b.real,
+      a.imag - b.imag,
+   };
+
+   return out;
+
+}
+
+static inline rarch_fft_complex_t rarch_fft_complex_conj(rarch_fft_complex_t a)
+{
+   rarch_fft_complex_t out = {
+      a.real, -a.imag,
+   };
+
+   return out;
+}
+
 rarch_fft_t *rarch_fft_new(unsigned block_size_log2);
 
 void rarch_fft_free(rarch_fft_t *fft);

audio/filters/eq.c

@@ -0,0 +1,105 @@
+/*  RetroArch - A frontend for libretro.
+ *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
+ *
+ *  RetroArch is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  RetroArch 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with RetroArch.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "dspfilter.h"
+#include <stdlib.h>
+#include <string.h>
+
+#include "../fft/fft.c"
+
+#ifndef M_PI
+#define M_PI 3.1415926535897932384626433832795
+#endif
+
+struct eq_data
+{
+   rarch_fft_t *fft;
+   float buffer[8 * 1024];
+
+   float *save;
+   float *block;
+   rarch_fft_complex_t *filter;
+   unsigned block_size;
+   unsigned block_ptr;
+};
+
+static void eq_free(void *data)
+{
+   struct eq_data *eq = (struct eq_data*)data;
+   if (!eq)
+      return;
+
+   rarch_fft_free(eq->fft);
+   free(eq->save);
+   free(eq->block);
+   free(eq->filter);
+   free(eq);
+}
+
+static void eq_process(void *data, struct dspfilter_output *output,
+      const struct dspfilter_input *input)
+{
+   struct eq_data *eq = (struct eq_data*)data;
+}
+
+static void *eq_init(const struct dspfilter_info *info,
+      const struct dspfilter_config *config, void *userdata)
+{
+   struct eq_data *eq = (struct eq_data*)calloc(1, sizeof(*eq));
+   if (!eq)
+      return NULL;
+
+   unsigned size_log2 = 8;
+   unsigned size = 1 << size_log2;
+
+   eq->block_size = size;
+
+   eq->save   = (float*)calloc(2 * size, sizeof(*eq->save));
+   eq->block  = (float*)calloc(2 * size, 2 * sizeof(*eq->block));
+   eq->filter = (rarch_fft_complex_t*)calloc(2 * size, sizeof(*eq->filter));
+   eq->fft    = rarch_fft_new(size_log2 + 1);
+
+   if (!eq->fft || !eq->save || !eq->block || !eq->filter)
+      goto error;
+
+   return eq;
+
+error:
+   eq_free(eq);
+   return NULL;
+}
+
+static const struct dspfilter_implementation eq_plug = {
+   eq_init,
+   eq_process,
+   eq_free,
+
+   DSPFILTER_API_VERSION,
+   "Linear-Phase FFT Equalizer",
+   "eq",
+};
+
+#ifdef HAVE_FILTERS_BUILTIN
+#define dspfilter_get_implementation eq_dspfilter_get_implementation
+#endif
+
+const struct dspfilter_implementation *eq_get_implementation(dspfilter_simd_mask_t mask)
+{
+   (void)mask;
+   return &eq_plug;
+}
+
+#undef dspfilter_get_implementation
+