Move the aec_rdft* files to a more proper place beneath APM and make them thread-safe.

webrtc/modules/audio_processing/utility/ooura_fft.cc

 /*
  * http://www.kurims.kyoto-u.ac.jp/~ooura/fft.html
  * Copyright Takuya OOURA, 1996-2001
  *
  * You may use, copy, modify and distribute this code for any purpose (include
  * commercial use) and without fee. Please refer to this package when you modify
  * this code.
  *
  * Changes by the WebRTC authors:
  *    - Trivial type modifications.
  *    - Minimal code subset to do rdft of length 128.
  *    - Optimizations because of known length.
+ *    - Removed the global variables by moving the code in to a class in order
+ *      to make it thread safe.
  *
  *  All changes are covered by the WebRTC license and IP grant:
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "webrtc/modules/audio_processing/aec/aec_rdft.h"
+#include "webrtc/modules/audio_processing//utility/ooura_fft.h"
 
 #include <math.h>
 
+#include "webrtc/modules/audio_processing/utility/ooura_fft_tables_common.h"
 #include "webrtc/system_wrappers/include/cpu_features_wrapper.h"
 #include "webrtc/typedefs.h"
 
-// These tables used to be computed at run-time. For example, refer to:
-// https://code.google.com/p/webrtc/source/browse/trunk/webrtc/modules/audio_processing/aec/aec_rdft.c?r=6564
-// to see the initialization code.
-const float rdft_w[64] = {
-    1.0000000000f, 0.0000000000f, 0.7071067691f, 0.7071067691f,
-    0.9238795638f, 0.3826834559f, 0.3826834559f, 0.9238795638f,
-    0.9807852507f, 0.1950903237f, 0.5555702448f, 0.8314695954f,
-    0.8314695954f, 0.5555702448f, 0.1950903237f, 0.9807852507f,
-    0.9951847196f, 0.0980171412f, 0.6343933344f, 0.7730104327f,
-    0.8819212914f, 0.4713967443f, 0.2902846634f, 0.9569403529f,
-    0.9569403529f, 0.2902846634f, 0.4713967443f, 0.8819212914f,
-    0.7730104327f, 0.6343933344f, 0.0980171412f, 0.9951847196f,
-    0.7071067691f, 0.4993977249f, 0.4975923598f, 0.4945882559f,
-    0.4903926253f, 0.4850156307f, 0.4784701765f, 0.4707720280f,
-    0.4619397819f, 0.4519946277f, 0.4409606457f, 0.4288643003f,
-    0.4157347977f, 0.4016037583f, 0.3865052164f, 0.3704755902f,
-    0.3535533845f, 0.3357794881f, 0.3171966672f, 0.2978496552f,
-    0.2777851224f, 0.2570513785f, 0.2356983721f, 0.2137775421f,
-    0.1913417280f, 0.1684449315f, 0.1451423317f, 0.1214900985f,
-    0.0975451618f, 0.0733652338f, 0.0490085706f, 0.0245338380f,
-};
-const float rdft_wk3ri_first[16] = {
-    1.000000000f, 0.000000000f, 0.382683456f, 0.923879564f,
-    0.831469536f, 0.555570245f, -0.195090353f, 0.980785251f,
-    0.956940353f, 0.290284693f, 0.098017156f, 0.995184720f,
-    0.634393334f, 0.773010492f, -0.471396863f, 0.881921172f,
-};
-const float rdft_wk3ri_second[16] = {
-    -0.707106769f, 0.707106769f, -0.923879564f, -0.382683456f,
-    -0.980785251f, 0.195090353f, -0.555570245f, -0.831469536f,
-    -0.881921172f, 0.471396863f, -0.773010492f, -0.634393334f,
-    -0.995184720f, -0.098017156f, -0.290284693f, -0.956940353f,
-};
-ALIGN16_BEG const float ALIGN16_END rdft_wk1r[32] = {
-    1.000000000f, 1.000000000f, 0.707106769f, 0.707106769f,
-    0.923879564f, 0.923879564f, 0.382683456f, 0.382683456f,
-    0.980785251f, 0.980785251f, 0.555570245f, 0.555570245f,
-    0.831469595f, 0.831469595f, 0.195090324f, 0.195090324f,
-    0.995184720f, 0.995184720f, 0.634393334f, 0.634393334f,
-    0.881921291f, 0.881921291f, 0.290284663f, 0.290284663f,
-    0.956940353f, 0.956940353f, 0.471396744f, 0.471396744f,
-    0.773010433f, 0.773010433f, 0.098017141f, 0.098017141f,
-};
-ALIGN16_BEG const float ALIGN16_END rdft_wk2r[32] = {
-    1.000000000f, 1.000000000f, -0.000000000f, -0.000000000f,
-    0.707106769f, 0.707106769f, -0.707106769f, -0.707106769f,
-    0.923879564f, 0.923879564f, -0.382683456f, -0.382683456f,
-    0.382683456f, 0.382683456f, -0.923879564f, -0.923879564f,
-    0.980785251f, 0.980785251f, -0.195090324f, -0.195090324f,
-    0.555570245f, 0.555570245f, -0.831469595f, -0.831469595f,
-    0.831469595f, 0.831469595f, -0.555570245f, -0.555570245f,
-    0.195090324f, 0.195090324f, -0.980785251f, -0.980785251f,
-};
-ALIGN16_BEG const float ALIGN16_END rdft_wk3r[32] = {
-    1.000000000f, 1.000000000f, -0.707106769f, -0.707106769f,
-    0.382683456f, 0.382683456f, -0.923879564f, -0.923879564f,
-    0.831469536f, 0.831469536f, -0.980785251f, -0.980785251f,
-    -0.195090353f, -0.195090353f, -0.555570245f, -0.555570245f,
-    0.956940353f, 0.956940353f, -0.881921172f, -0.881921172f,
-    0.098017156f, 0.098017156f, -0.773010492f, -0.773010492f,
-    0.634393334f, 0.634393334f, -0.995184720f, -0.995184720f,
-    -0.471396863f, -0.471396863f, -0.290284693f, -0.290284693f,
-};
-ALIGN16_BEG const float ALIGN16_END rdft_wk1i[32] = {
-    -0.000000000f, 0.000000000f, -0.707106769f, 0.707106769f,
-    -0.382683456f, 0.382683456f, -0.923879564f, 0.923879564f,
-    -0.195090324f, 0.195090324f, -0.831469595f, 0.831469595f,
-    -0.555570245f, 0.555570245f, -0.980785251f, 0.980785251f,
-    -0.098017141f, 0.098017141f, -0.773010433f, 0.773010433f,
-    -0.471396744f, 0.471396744f, -0.956940353f, 0.956940353f,
-    -0.290284663f, 0.290284663f, -0.881921291f, 0.881921291f,
-    -0.634393334f, 0.634393334f, -0.995184720f, 0.995184720f,
-};
-ALIGN16_BEG const float ALIGN16_END rdft_wk2i[32] = {
-    -0.000000000f, 0.000000000f, -1.000000000f, 1.000000000f,
-    -0.707106769f, 0.707106769f, -0.707106769f, 0.707106769f,
-    -0.382683456f, 0.382683456f, -0.923879564f, 0.923879564f,
-    -0.923879564f, 0.923879564f, -0.382683456f, 0.382683456f,
-    -0.195090324f, 0.195090324f, -0.980785251f, 0.980785251f,
-    -0.831469595f, 0.831469595f, -0.555570245f, 0.555570245f,
-    -0.555570245f, 0.555570245f, -0.831469595f, 0.831469595f,
-    -0.980785251f, 0.980785251f, -0.195090324f, 0.195090324f,
-};
-ALIGN16_BEG const float ALIGN16_END rdft_wk3i[32] = {
-    -0.000000000f, 0.000000000f, -0.707106769f, 0.707106769f,
-    -0.923879564f, 0.923879564f, 0.382683456f, -0.382683456f,
-    -0.555570245f, 0.555570245f, -0.195090353f, 0.195090353f,
-    -0.980785251f, 0.980785251f, 0.831469536f, -0.831469536f,
-    -0.290284693f, 0.290284693f, -0.471396863f, 0.471396863f,
-    -0.995184720f, 0.995184720f, 0.634393334f, -0.634393334f,
-    -0.773010492f, 0.773010492f, 0.098017156f, -0.098017156f,
-    -0.881921172f, 0.881921172f, 0.956940353f, -0.956940353f,
-};
-ALIGN16_BEG const float ALIGN16_END cftmdl_wk1r[4] = {
-    0.707106769f, 0.707106769f, 0.707106769f, -0.707106769f,
-};
+namespace webrtc {
 
-static void bitrv2_128_C(float* a) {
-  /*
-      Following things have been attempted but are no faster:
-      (a) Storing the swap indexes in a LUT (index calculations are done
-          for 'free' while waiting on memory/L1).
-      (b) Consolidate the load/store of two consecutive floats by a 64 bit
-          integer (execution is memory/L1 bound).
-      (c) Do a mix of floats and 64 bit integer to maximize register
-          utilization (execution is memory/L1 bound).
-      (d) Replacing ip[i] by ((k<<31)>>25) + ((k >> 1)<<5).
-      (e) Hard-coding of the offsets to completely eliminates index
-          calculations.
-  */
+namespace {
 
-  unsigned int j, j1, k, k1;
-  float xr, xi, yr, yi;
-
-  static const int ip[4] = {0, 64, 32, 96};
-  for (k = 0; k < 4; k++) {
-    for (j = 0; j < k; j++) {
-      j1 = 2 * j + ip[k];
-      k1 = 2 * k + ip[j];
-      xr = a[j1 + 0];
-      xi = a[j1 + 1];
-      yr = a[k1 + 0];
-      yi = a[k1 + 1];
-      a[j1 + 0] = yr;
-      a[j1 + 1] = yi;
-      a[k1 + 0] = xr;
-      a[k1 + 1] = xi;
-      j1 += 8;
-      k1 += 16;
-      xr = a[j1 + 0];
-      xi = a[j1 + 1];
-      yr = a[k1 + 0];
-      yi = a[k1 + 1];
-      a[j1 + 0] = yr;
-      a[j1 + 1] = yi;
-      a[k1 + 0] = xr;
-      a[k1 + 1] = xi;
-      j1 += 8;
-      k1 -= 8;
-      xr = a[j1 + 0];
-      xi = a[j1 + 1];
-      yr = a[k1 + 0];
-      yi = a[k1 + 1];
-      a[j1 + 0] = yr;
-      a[j1 + 1] = yi;
-      a[k1 + 0] = xr;
-      a[k1 + 1] = xi;
-      j1 += 8;
-      k1 += 16;
-      xr = a[j1 + 0];
-      xi = a[j1 + 1];
-      yr = a[k1 + 0];
-      yi = a[k1 + 1];
-      a[j1 + 0] = yr;
-      a[j1 + 1] = yi;
-      a[k1 + 0] = xr;
-      a[k1 + 1] = xi;
-    }
-    j1 = 2 * k + 8 + ip[k];
-    k1 = j1 + 8;
-    xr = a[j1 + 0];
-    xi = a[j1 + 1];
-    yr = a[k1 + 0];
-    yi = a[k1 + 1];
-    a[j1 + 0] = yr;
-    a[j1 + 1] = yi;
-    a[k1 + 0] = xr;
-    a[k1 + 1] = xi;
-  }
-}
-
+#if !(defined(MIPS_FPU_LE) || defined(WEBRTC_HAS_NEON))
 static void cft1st_128_C(float* a) {
   const int n = 128;
   int j, k1, k2;
   float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
   float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
 
   // The processing of the first set of elements was simplified in C to avoid
   // some operations (multiplication by zero or one, addition of two elements
   // multiplied by the same weight, ...).
   x0r = a[0] + a[2];
@@ skipping 214 matching lines @@
       a[j1 + 0] = wk1r * x0r - wk1i * x0i;
       a[j1 + 1] = wk1r * x0i + wk1i * x0r;
       x0r = x1r + x3i;
       x0i = x1i - x3r;
       a[j3 + 0] = wk3r * x0r - wk3i * x0i;
       a[j3 + 1] = wk3r * x0i + wk3i * x0r;
     }
   }
 }
 
-static void cftfsub_128_C(float* a) {
-  int j, j1, j2, j3, l;
-  float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
-
-  cft1st_128(a);
-  cftmdl_128(a);
-  l = 32;
-  for (j = 0; j < l; j += 2) {
-    j1 = j + l;
-    j2 = j1 + l;
-    j3 = j2 + l;
-    x0r = a[j] + a[j1];
-    x0i = a[j + 1] + a[j1 + 1];
-    x1r = a[j] - a[j1];
-    x1i = a[j + 1] - a[j1 + 1];
-    x2r = a[j2] + a[j3];
-    x2i = a[j2 + 1] + a[j3 + 1];
-    x3r = a[j2] - a[j3];
-    x3i = a[j2 + 1] - a[j3 + 1];
-    a[j] = x0r + x2r;
-    a[j + 1] = x0i + x2i;
-    a[j2] = x0r - x2r;
-    a[j2 + 1] = x0i - x2i;
-    a[j1] = x1r - x3i;
-    a[j1 + 1] = x1i + x3r;
-    a[j3] = x1r + x3i;
-    a[j3 + 1] = x1i - x3r;
-  }
-}
-
-static void cftbsub_128_C(float* a) {
-  int j, j1, j2, j3, l;
-  float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
-
-  cft1st_128(a);
-  cftmdl_128(a);
-  l = 32;
-
-  for (j = 0; j < l; j += 2) {
-    j1 = j + l;
-    j2 = j1 + l;
-    j3 = j2 + l;
-    x0r = a[j] + a[j1];
-    x0i = -a[j + 1] - a[j1 + 1];
-    x1r = a[j] - a[j1];
-    x1i = -a[j + 1] + a[j1 + 1];
-    x2r = a[j2] + a[j3];
-    x2i = a[j2 + 1] + a[j3 + 1];
-    x3r = a[j2] - a[j3];
-    x3i = a[j2 + 1] - a[j3 + 1];
-    a[j] = x0r + x2r;
-    a[j + 1] = x0i - x2i;
-    a[j2] = x0r - x2r;
-    a[j2 + 1] = x0i + x2i;
-    a[j1] = x1r - x3i;
-    a[j1 + 1] = x1i - x3r;
-    a[j3] = x1r + x3i;
-    a[j3 + 1] = x1i + x3r;
-  }
-}
-
 static void rftfsub_128_C(float* a) {
   const float* c = rdft_w + 32;
   int j1, j2, k1, k2;
   float wkr, wki, xr, xi, yr, yi;
 
   for (j1 = 1, j2 = 2; j2 < 64; j1 += 1, j2 += 2) {
     k2 = 128 - j2;
     k1 = 32 - j1;
     wkr = 0.5f - c[k1];
     wki = c[j1];
@@ skipping 23 matching lines @@
     xi = a[j2 + 1] + a[k2 + 1];
     yr = wkr * xr + wki * xi;
     yi = wkr * xi - wki * xr;
     a[j2 + 0] = a[j2 + 0] - yr;
     a[j2 + 1] = yi - a[j2 + 1];
     a[k2 + 0] = yr + a[k2 + 0];
     a[k2 + 1] = yi - a[k2 + 1];
   }
   a[65] = -a[65];
 }
+#endif
 
-void aec_rdft_forward_128(float* a) {
+
+}  // namespace
+
+OouraFft::OouraFft() {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+  use_sse2_ = (WebRtc_GetCPUInfo(kSSE2) != 0);
+#else
+  use_sse2_ = false;
+#endif
+}
+
+OouraFft::~OouraFft() = default;
+
+void OouraFft::Fft(float* a) const {
   float xi;
   bitrv2_128(a);
   cftfsub_128(a);
   rftfsub_128(a);
   xi = a[0] - a[1];
   a[0] += a[1];
   a[1] = xi;
 }
-
-void aec_rdft_inverse_128(float* a) {
+void OouraFft::InverseFft(float* a) const {
   a[1] = 0.5f * (a[0] - a[1]);
   a[0] -= a[1];
   rftbsub_128(a);
   bitrv2_128(a);
   cftbsub_128(a);
 }
 
-// code path selection
-RftSub128 cft1st_128;
-RftSub128 cftmdl_128;
-RftSub128 rftfsub_128;
-RftSub128 rftbsub_128;
-RftSub128 cftfsub_128;
-RftSub128 cftbsub_128;
-RftSub128 bitrv2_128;
-
-void aec_rdft_init(void) {
-  cft1st_128 = cft1st_128_C;
-  cftmdl_128 = cftmdl_128_C;
-  rftfsub_128 = rftfsub_128_C;
-  rftbsub_128 = rftbsub_128_C;
-  cftfsub_128 = cftfsub_128_C;
-  cftbsub_128 = cftbsub_128_C;
-  bitrv2_128 = bitrv2_128_C;
-#if defined(WEBRTC_ARCH_X86_FAMILY)
-  if (WebRtc_GetCPUInfo(kSSE2)) {
-    aec_rdft_init_sse2();
+void OouraFft::cft1st_128(float* a) const {
+#if defined(MIPS_FPU_LE)
+  cft1st_128_mips(a);
+#elif defined(WEBRTC_HAS_NEON)
+  cft1st_128_neon(a);
+#else
+  if (use_sse2_) {
+    cft1st_128_SSE2(a);
+  } else {
+    cft1st_128_C(a);
   }
 #endif
+}
+void OouraFft::cftmdl_128(float* a) const {
 #if defined(MIPS_FPU_LE)
-  aec_rdft_init_mips();
-#endif
-#if defined(WEBRTC_HAS_NEON)
-  aec_rdft_init_neon();
+  cftmdl_128_mips(a);
+#elif defined(WEBRTC_HAS_NEON)
+  cftmdl_128_neon(a);
+#else
+  if (use_sse2_) {
+    cftmdl_128_SSE2(a);
+  } else {
+    cftmdl_128_C(a);
+  }
 #endif
 }
+void OouraFft::rftfsub_128(float* a) const {
+#if defined(MIPS_FPU_LE)
+  rftfsub_128_mips(a);
+#elif defined(WEBRTC_HAS_NEON)
+  rftfsub_128_neon(a);
+#else
+  if (use_sse2_) {
+    rftfsub_128_SSE2(a);
+  } else {
+    rftfsub_128_C(a);
+  }
+#endif
+}
+
+void OouraFft::rftbsub_128(float* a) const {
+#if defined(MIPS_FPU_LE)
+  rftbsub_128_mips(a);
+#elif defined(WEBRTC_HAS_NEON)
+  rftbsub_128_neon(a);
+#else
+  if (use_sse2_) {
+    rftbsub_128_SSE2(a);
+  } else {
+    rftbsub_128_C(a);
+  }
+#endif
+}
+
+void OouraFft::cftbsub_128(float* a) const {
+  int j, j1, j2, j3, l;
+  float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
+
+  cft1st_128(a);
+  cftmdl_128(a);
+  l = 32;
+
+  for (j = 0; j < l; j += 2) {
+    j1 = j + l;
+    j2 = j1 + l;
+    j3 = j2 + l;
+    x0r = a[j] + a[j1];
+    x0i = -a[j + 1] - a[j1 + 1];
+    x1r = a[j] - a[j1];
+    x1i = -a[j + 1] + a[j1 + 1];
+    x2r = a[j2] + a[j3];
+    x2i = a[j2 + 1] + a[j3 + 1];
+    x3r = a[j2] - a[j3];
+    x3i = a[j2 + 1] - a[j3 + 1];
+    a[j] = x0r + x2r;
+    a[j + 1] = x0i - x2i;
+    a[j2] = x0r - x2r;
+    a[j2 + 1] = x0i + x2i;
+    a[j1] = x1r - x3i;
+    a[j1 + 1] = x1i - x3r;
+    a[j3] = x1r + x3i;
+    a[j3 + 1] = x1i + x3r;
+  }
+}
+
+void OouraFft::cftfsub_128(float* a) const {
+  int j, j1, j2, j3, l;
+  float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
+
+  cft1st_128(a);
+  cftmdl_128(a);
+  l = 32;
+  for (j = 0; j < l; j += 2) {
+    j1 = j + l;
+    j2 = j1 + l;
+    j3 = j2 + l;
+    x0r = a[j] + a[j1];
+    x0i = a[j + 1] + a[j1 + 1];
+    x1r = a[j] - a[j1];
+    x1i = a[j + 1] - a[j1 + 1];
+    x2r = a[j2] + a[j3];
+    x2i = a[j2 + 1] + a[j3 + 1];
+    x3r = a[j2] - a[j3];
+    x3i = a[j2 + 1] - a[j3 + 1];
+    a[j] = x0r + x2r;
+    a[j + 1] = x0i + x2i;
+    a[j2] = x0r - x2r;
+    a[j2 + 1] = x0i - x2i;
+    a[j1] = x1r - x3i;
+    a[j1 + 1] = x1i + x3r;
+    a[j3] = x1r + x3i;
+    a[j3 + 1] = x1i - x3r;
+  }
+}
+
+void OouraFft::bitrv2_128(float* a) const {
+  /*
+      Following things have been attempted but are no faster:
+      (a) Storing the swap indexes in a LUT (index calculations are done
+          for 'free' while waiting on memory/L1).
+      (b) Consolidate the load/store of two consecutive floats by a 64 bit
+          integer (execution is memory/L1 bound).
+      (c) Do a mix of floats and 64 bit integer to maximize register
+          utilization (execution is memory/L1 bound).
+      (d) Replacing ip[i] by ((k<<31)>>25) + ((k >> 1)<<5).
+      (e) Hard-coding of the offsets to completely eliminates index
+          calculations.
+  */
+
+  unsigned int j, j1, k, k1;
+  float xr, xi, yr, yi;
+
+  const int ip[4] = {0, 64, 32, 96};
+  for (k = 0; k < 4; k++) {
+    for (j = 0; j < k; j++) {
+      j1 = 2 * j + ip[k];
+      k1 = 2 * k + ip[j];
+      xr = a[j1 + 0];
+      xi = a[j1 + 1];
+      yr = a[k1 + 0];
+      yi = a[k1 + 1];
+      a[j1 + 0] = yr;
+      a[j1 + 1] = yi;
+      a[k1 + 0] = xr;
+      a[k1 + 1] = xi;
+      j1 += 8;
+      k1 += 16;
+      xr = a[j1 + 0];
+      xi = a[j1 + 1];
+      yr = a[k1 + 0];
+      yi = a[k1 + 1];
+      a[j1 + 0] = yr;
+      a[j1 + 1] = yi;
+      a[k1 + 0] = xr;
+      a[k1 + 1] = xi;
+      j1 += 8;
+      k1 -= 8;
+      xr = a[j1 + 0];
+      xi = a[j1 + 1];
+      yr = a[k1 + 0];
+      yi = a[k1 + 1];
+      a[j1 + 0] = yr;
+      a[j1 + 1] = yi;
+      a[k1 + 0] = xr;
+      a[k1 + 1] = xi;
+      j1 += 8;
+      k1 += 16;
+      xr = a[j1 + 0];
+      xi = a[j1 + 1];
+      yr = a[k1 + 0];
+      yi = a[k1 + 1];
+      a[j1 + 0] = yr;
+      a[j1 + 1] = yi;
+      a[k1 + 0] = xr;
+      a[k1 + 1] = xi;
+    }
+    j1 = 2 * k + 8 + ip[k];
+    k1 = j1 + 8;
+    xr = a[j1 + 0];
+    xi = a[j1 + 1];
+    yr = a[k1 + 0];
+    yi = a[k1 + 1];
+    a[j1 + 0] = yr;
+    a[j1 + 1] = yi;
+    a[k1 + 0] = xr;
+    a[k1 + 1] = xi;
+  }
+}
+
+}  // namespace webrtc