diff --git a/modules/audio_processing/aec/main/source/aec_core.c b/modules/audio_processing/aec/main/source/aec_core.c
index 41f561f90..3f88d6d96 100644
--- a/modules/audio_processing/aec/main/source/aec_core.c
+++ b/modules/audio_processing/aec/main/source/aec_core.c
@@ -123,8 +123,7 @@ static void ProcessBlock(aec_t *aec, const short *farend,
 static void BufferFar(aec_t *aec, const short *farend, int farLen);
 static void FetchFar(aec_t *aec, short *farend, int farLen, int knownDelay);
 
-static void NonLinearProcessing(aec_t *aec, int *ip, float *wfft, short *output,
-                         short *outputH);
+static void NonLinearProcessing(aec_t *aec, short *output, short *outputH);
 
 static void GetHighbandGain(const float *lambda, float *nlpGainHband);
 
@@ -256,8 +255,7 @@ static void ScaleErrorSignal(aec_t *aec, float ef[2][PART_LEN1])
   }
 }
 
-static void FilterAdaptation(aec_t *aec, float *fft, float ef[2][PART_LEN1],
-                      int ip[IP_LEN], float wfft[W_LEN]) {
+static void FilterAdaptation(aec_t *aec, float *fft, float ef[2][PART_LEN1]) {
   int i, j;
   for (i = 0; i < NR_PART; i++) {
     int xPos = (i + aec->xfBufBlockPos)*(PART_LEN1);
@@ -292,7 +290,7 @@ static void FilterAdaptation(aec_t *aec, float *fft, float ef[2][PART_LEN1],
                    -aec->xfBuf[1][xPos + PART_LEN],
                    ef[0][PART_LEN], ef[1][PART_LEN]);
 
-    aec_rdft_128(-1, fft, ip, wfft);
+    aec_rdft_128(-1, fft);
     memset(fft + PART_LEN, 0, sizeof(float) * PART_LEN);
 
     // fft scaling
@@ -302,7 +300,7 @@ static void FilterAdaptation(aec_t *aec, float *fft, float ef[2][PART_LEN1],
         fft[j] *= scale;
       }
     }
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
 
     aec->wfBuf[0][pos] += fft[0];
     aec->wfBuf[0][pos + PART_LEN] += fft[1];
@@ -574,8 +572,6 @@ static void ProcessBlock(aec_t *aec, const short *farend,
     float fft[PART_LEN2];
     float xf[2][PART_LEN1], yf[2][PART_LEN1], ef[2][PART_LEN1];
     complex_t df[PART_LEN1];
-    int ip[IP_LEN];
-    float wfft[W_LEN];
 
     const float gPow[2] = {0.9f, 0.1f};
 
@@ -613,9 +609,7 @@ static void ProcessBlock(aec_t *aec, const short *farend,
         memcpy(aec->dBufH + PART_LEN, dH, sizeof(float) * PART_LEN);
     }
 
-    // Setting this on the first call initializes work arrays.
-    ip[0] = 0;
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
 
     // Far fft
     xf[1][0] = 0;
@@ -630,7 +624,7 @@ static void ProcessBlock(aec_t *aec, const short *farend,
 
     // Near fft
     memcpy(fft, aec->dBuf, sizeof(float) * PART_LEN2);
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
     df[0][1] = 0;
     df[PART_LEN][1] = 0;
     df[0][0] = fft[0];
@@ -706,7 +700,7 @@ static void ProcessBlock(aec_t *aec, const short *farend,
         fft[2 * i] = yf[0][i];
         fft[2 * i + 1] = yf[1][i];
     }
-    aec_rdft_128(-1, fft, ip, wfft);
+    aec_rdft_128(-1, fft);
 
     scale = 2.0f / PART_LEN2;
     for (i = 0; i < PART_LEN; i++) {
@@ -721,7 +715,7 @@ static void ProcessBlock(aec_t *aec, const short *farend,
     memcpy(aec->eBuf + PART_LEN, e, sizeof(float) * PART_LEN);
     memset(fft, 0, sizeof(float) * PART_LEN);
     memcpy(fft + PART_LEN, e, sizeof(float) * PART_LEN);
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
 
     ef[1][0] = 0;
     ef[1][PART_LEN] = 0;
@@ -738,12 +732,12 @@ static void ProcessBlock(aec_t *aec, const short *farend,
     if (aec->adaptToggle) {
 #endif
         // Filter adaptation
-        WebRtcAec_FilterAdaptation(aec, fft, ef, ip, wfft);
+        WebRtcAec_FilterAdaptation(aec, fft, ef);
 #ifdef G167
     }
 #endif
 
-    NonLinearProcessing(aec, ip, wfft, output, outputH);
+    NonLinearProcessing(aec, output, outputH);
 
 #if defined(AEC_DEBUG) || defined(G167)
     for (i = 0; i < PART_LEN; i++) {
@@ -777,7 +771,7 @@ static void ProcessBlock(aec_t *aec, const short *farend,
 #endif
 }
 
-static void NonLinearProcessing(aec_t *aec, int *ip, float *wfft, short *output, short *outputH)
+static void NonLinearProcessing(aec_t *aec, short *output, short *outputH)
 {
     float efw[2][PART_LEN1], dfw[2][PART_LEN1];
     complex_t xfw[PART_LEN1];
@@ -844,7 +838,7 @@ static void NonLinearProcessing(aec_t *aec, int *ip, float *wfft, short *output,
         fft[i] = aec->xBuf[i] * sqrtHanning[i];
         fft[PART_LEN + i] = aec->xBuf[PART_LEN + i] * sqrtHanning[PART_LEN - i];
     }
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
 
     xfw[0][1] = 0;
     xfw[PART_LEN][1] = 0;
@@ -866,7 +860,7 @@ static void NonLinearProcessing(aec_t *aec, int *ip, float *wfft, short *output,
         fft[i] = aec->dBuf[i] * sqrtHanning[i];
         fft[PART_LEN + i] = aec->dBuf[PART_LEN + i] * sqrtHanning[PART_LEN - i];
     }
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
 
     dfw[1][0] = 0;
     dfw[1][PART_LEN] = 0;
@@ -882,7 +876,7 @@ static void NonLinearProcessing(aec_t *aec, int *ip, float *wfft, short *output,
         fft[i] = aec->eBuf[i] * sqrtHanning[i];
         fft[PART_LEN + i] = aec->eBuf[PART_LEN + i] * sqrtHanning[PART_LEN - i];
     }
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
     efw[1][0] = 0;
     efw[1][PART_LEN] = 0;
     efw[0][0] = fft[0];
@@ -1059,7 +1053,7 @@ static void NonLinearProcessing(aec_t *aec, int *ip, float *wfft, short *output,
         // Sign change required by Ooura fft.
         fft[2*i + 1] = -efw[1][i];
     }
-    aec_rdft_128(-1, fft, ip, wfft);
+    aec_rdft_128(-1, fft);
 
     // Overlap and add to obtain output.
     scale = 2.0f / PART_LEN2;
@@ -1091,7 +1085,7 @@ static void NonLinearProcessing(aec_t *aec, int *ip, float *wfft, short *output,
                 fft[2*i] = comfortNoiseHband[i][0];
                 fft[2*i + 1] = comfortNoiseHband[i][1];
             }
-            aec_rdft_128(-1, fft, ip, wfft);
+            aec_rdft_128(-1, fft);
             scale = 2.0f / PART_LEN2;
         }
 
diff --git a/modules/audio_processing/aec/main/source/aec_core.h b/modules/audio_processing/aec/main/source/aec_core.h
index 7abefc1e2..3386b92fc 100644
--- a/modules/audio_processing/aec/main/source/aec_core.h
+++ b/modules/audio_processing/aec/main/source/aec_core.h
@@ -172,8 +172,7 @@ extern WebRtcAec_ScaleErrorSignal_t WebRtcAec_ScaleErrorSignal;
 #define IP_LEN PART_LEN // this must be at least ceil(2 + sqrt(PART_LEN))
 #define W_LEN PART_LEN
 typedef void (*WebRtcAec_FilterAdaptation_t)
-  (aec_t *aec, float *fft, float ef[2][PART_LEN1], int ip[IP_LEN],
-   float wfft[W_LEN]);
+  (aec_t *aec, float *fft, float ef[2][PART_LEN1]);
 extern WebRtcAec_FilterAdaptation_t WebRtcAec_FilterAdaptation;
 typedef void (*WebRtcAec_OverdriveAndSuppress_t)
   (aec_t *aec, float hNl[PART_LEN1], const float hNlFb, float efw[2][PART_LEN1]);
diff --git a/modules/audio_processing/aec/main/source/aec_core_sse2.c b/modules/audio_processing/aec/main/source/aec_core_sse2.c
index 0a00a2e3c..8dbad75be 100644
--- a/modules/audio_processing/aec/main/source/aec_core_sse2.c
+++ b/modules/audio_processing/aec/main/source/aec_core_sse2.c
@@ -126,8 +126,7 @@ static void ScaleErrorSignalSSE2(aec_t *aec, float ef[2][PART_LEN1])
   }
 }
 
-static void FilterAdaptationSSE2(aec_t *aec, float *fft, float ef[2][PART_LEN1],
-                          int ip[IP_LEN], float wfft[W_LEN]) {
+static void FilterAdaptationSSE2(aec_t *aec, float *fft, float ef[2][PART_LEN1]) {
   int i, j;
   for (i = 0; i < NR_PART; i++) {
     int xPos = (i + aec->xfBufBlockPos)*(PART_LEN1);
@@ -175,7 +174,7 @@ static void FilterAdaptationSSE2(aec_t *aec, float *fft, float ef[2][PART_LEN1],
                    -aec->xfBuf[1][xPos + PART_LEN],
                    ef[0][PART_LEN], ef[1][PART_LEN]);
 
-    aec_rdft_128(-1, fft, ip, wfft);
+    aec_rdft_128(-1, fft);
     memset(fft + PART_LEN, 0, sizeof(float)*PART_LEN);
 
     // fft scaling
@@ -188,7 +187,7 @@ static void FilterAdaptationSSE2(aec_t *aec, float *fft, float ef[2][PART_LEN1],
         _mm_storeu_ps(&fft[j], fft_scale);
       }
     }
-    aec_rdft_128(1, fft, ip, wfft);
+    aec_rdft_128(1, fft);
 
     {
       float wt1 = aec->wfBuf[1][pos];
diff --git a/modules/audio_processing/aec/main/source/aec_rdft.c b/modules/audio_processing/aec/main/source/aec_rdft.c
index 15f5fcf9d..bba372055 100644
--- a/modules/audio_processing/aec/main/source/aec_rdft.c
+++ b/modules/audio_processing/aec/main/source/aec_rdft.c
@@ -24,6 +24,9 @@
 #include "aec_rdft.h"
 #include "system_wrappers/interface/cpu_features_wrapper.h"
 
+float rdft_w[64];
+static int ip[16];
+
 static void bitrv2_32or128(int n, int *ip, float *a) {
   // n is 32 or 128
   int j, j1, k, k1, m, m2;
@@ -98,7 +101,7 @@ static void bitrv2_32or128(int n, int *ip, float *a) {
   }
 }
 
-static void makewt(int *ip, float *w) {
+static void makewt_32() {
   const int nw = 32;
   int j, nwh;
   float delta, x, y;
@@ -107,22 +110,23 @@ static void makewt(int *ip, float *w) {
   ip[1] = 1;
   nwh = nw >> 1;
   delta = atanf(1.0f) / nwh;
-  w[0] = 1;
-  w[1] = 0;
-  w[nwh] = cosf(delta * nwh);
-  w[nwh + 1] = w[nwh];
+  rdft_w[0] = 1;
+  rdft_w[1] = 0;
+  rdft_w[nwh] = cosf(delta * nwh);
+  rdft_w[nwh + 1] = rdft_w[nwh];
   for (j = 2; j < nwh; j += 2) {
     x = cosf(delta * j);
     y = sinf(delta * j);
-    w[j] = x;
-    w[j + 1] = y;
-    w[nw - j] = y;
-    w[nw - j + 1] = x;
+    rdft_w[j] = x;
+    rdft_w[j + 1] = y;
+    rdft_w[nw - j] = y;
+    rdft_w[nw - j + 1] = x;
   }
-  bitrv2_32or128(nw, ip + 2, w);
+  bitrv2_32or128(nw, ip + 2, rdft_w);
 }
 
-static void makect_32(int *ip, float *c) {
+static void makect_32() {
+  float *c = rdft_w + 32;
   const int nc = 32;
   int j, nch;
   float delta;
@@ -138,7 +142,7 @@ static void makect_32(int *ip, float *c) {
   }
 }
 
-static void cft1st_128(float *a, float *w) {
+static void cft1st_128(float *a) {
   const int n = 128;
   int j, k1, k2;
   float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
@@ -160,7 +164,7 @@ static void cft1st_128(float *a, float *w) {
   a[3] = x1i + x3r;
   a[6] = x1r + x3i;
   a[7] = x1i - x3r;
-  wk1r = w[2];
+  wk1r = rdft_w[2];
   x0r = a[8] + a[10];
   x0i = a[9] + a[11];
   x1r = a[8] - a[10];
@@ -185,10 +189,10 @@ static void cft1st_128(float *a, float *w) {
   for (j = 16; j < n; j += 16) {
     k1 += 2;
     k2 = 2 * k1;
-    wk2r = w[k1];
-    wk2i = w[k1 + 1];
-    wk1r = w[k2];
-    wk1i = w[k2 + 1];
+    wk2r = rdft_w[k1];
+    wk2i = rdft_w[k1 + 1];
+    wk1r = rdft_w[k2];
+    wk1i = rdft_w[k2 + 1];
     wk3r = wk1r - 2 * wk2i * wk1i;
     wk3i = 2 * wk2i * wk1r - wk1i;
     x0r = a[j] + a[j + 2];
@@ -213,8 +217,8 @@ static void cft1st_128(float *a, float *w) {
     x0i = x1i - x3r;
     a[j + 6] = wk3r * x0r - wk3i * x0i;
     a[j + 7] = wk3r * x0i + wk3i * x0r;
-    wk1r = w[k2 + 2];
-    wk1i = w[k2 + 3];
+    wk1r = rdft_w[k2 + 2];
+    wk1i = rdft_w[k2 + 3];
     wk3r = wk1r - 2 * wk2r * wk1i;
     wk3i = 2 * wk2r * wk1r - wk1i;
     x0r = a[j + 8] + a[j + 10];
@@ -242,7 +246,7 @@ static void cft1st_128(float *a, float *w) {
   }
 }
 
-static void cftmdl_128(int l, float *a, float *w) {
+static void cftmdl_128(int l, float *a) {
   const int n = 128;
   int j, j1, j2, j3, k, k1, k2, m, m2;
   float wk1r, wk1i, wk2r, wk2i, wk3r, wk3i;
@@ -270,7 +274,7 @@ static void cftmdl_128(int l, float *a, float *w) {
     a[j3] = x1r + x3i;
     a[j3 + 1] = x1i - x3r;
   }
-  wk1r = w[2];
+  wk1r = rdft_w[2];
   for (j = m; j < l + m; j += 2) {
     j1 = j + l;
     j2 = j1 + l;
@@ -301,10 +305,10 @@ static void cftmdl_128(int l, float *a, float *w) {
   for (k = m2; k < n; k += m2) {
     k1 += 2;
     k2 = 2 * k1;
-    wk2r = w[k1];
-    wk2i = w[k1 + 1];
-    wk1r = w[k2];
-    wk1i = w[k2 + 1];
+    wk2r = rdft_w[k1];
+    wk2i = rdft_w[k1 + 1];
+    wk1r = rdft_w[k2];
+    wk1i = rdft_w[k2 + 1];
     wk3r = wk1r - 2 * wk2i * wk1i;
     wk3i = 2 * wk2i * wk1r - wk1i;
     for (j = k; j < l + k; j += 2) {
@@ -334,8 +338,8 @@ static void cftmdl_128(int l, float *a, float *w) {
       a[j3] = wk3r * x0r - wk3i * x0i;
       a[j3 + 1] = wk3r * x0i + wk3i * x0r;
     }
-    wk1r = w[k2 + 2];
-    wk1i = w[k2 + 3];
+    wk1r = rdft_w[k2 + 2];
+    wk1i = rdft_w[k2 + 3];
     wk3r = wk1r - 2 * wk2r * wk1i;
     wk3i = 2 * wk2r * wk1r - wk1i;
     for (j = k + m; j < l + (k + m); j += 2) {
@@ -368,12 +372,12 @@ static void cftmdl_128(int l, float *a, float *w) {
   }
 }
 
-static void cftfsub_128(float *a, float *w) {
+static void cftfsub_128(float *a) {
   int j, j1, j2, j3, l;
   float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
 
-  cft1st_128(a, w);
-  cftmdl_128(8, a, w);
+  cft1st_128(a);
+  cftmdl_128(8, a);
   l = 32;
   for (j = 0; j < l; j += 2) {
     j1 = j + l;
@@ -398,12 +402,12 @@ static void cftfsub_128(float *a, float *w) {
   }
 }
 
-static void cftbsub_128(float *a, float *w) {
+static void cftbsub_128(float *a) {
   int j, j1, j2, j3, l;
   float x0r, x0i, x1r, x1i, x2r, x2i, x3r, x3i;
 
-  cft1st_128(a, w);
-  cftmdl_128(8, a, w);
+  cft1st_128(a);
+  cftmdl_128(8, a);
   l = 32;
 
   for (j = 0; j < l; j += 2) {
@@ -429,7 +433,8 @@ static void cftbsub_128(float *a, float *w) {
   }
 }
 
-static void rftfsub_128_C(float *a, float *c) {
+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;
 
@@ -449,7 +454,8 @@ static void rftfsub_128_C(float *a, float *c) {
   }
 }
 
-static void rftbsub_128_C(float *a, float *c) {
+static void rftbsub_128_C(float *a) {
+  const float *c = rdft_w + 32;
   int j1, j2, k1, k2;
   float wkr, wki, xr, xi, yr, yi;
 
@@ -471,33 +477,25 @@ static void rftbsub_128_C(float *a, float *c) {
   a[65] = -a[65];
 }
 
-void aec_rdft_128(int isgn, float *a, int *ip, float *w)
-{
+void aec_rdft_128(int isgn, float *a) {
   const int n = 128;
   int nw;
   float xi;
 
   nw = ip[0];
-  if (n > (nw << 2)) {
-    nw = n >> 2;
-    makewt(ip, w);
-  }
-  if (n > (ip[1] << 2)) {
-    makect_32(ip, w + nw);
-  }
   if (isgn >= 0) {
     bitrv2_32or128(n, ip + 2, a);
-    cftfsub_128(a, w);
-    rftfsub_128(a, w + nw);
+    cftfsub_128(a);
+    rftfsub_128(a);
     xi = a[0] - a[1];
     a[0] += a[1];
     a[1] = xi;
   } else {
     a[1] = 0.5f * (a[0] - a[1]);
     a[0] -= a[1];
-    rftbsub_128(a, w + nw);
+    rftbsub_128(a);
     bitrv2_32or128(n, ip + 2, a);
-    cftbsub_128(a, w);
+    cftbsub_128(a);
   }
 }
 
@@ -513,4 +511,7 @@ void aec_rdft_init(void) {
     aec_rdft_init_sse2();
 #endif
   }
+  // init library constants.
+  makewt_32();
+  makect_32();
 }
diff --git a/modules/audio_processing/aec/main/source/aec_rdft.h b/modules/audio_processing/aec/main/source/aec_rdft.h
index add162c34..335256674 100644
--- a/modules/audio_processing/aec/main/source/aec_rdft.h
+++ b/modules/audio_processing/aec/main/source/aec_rdft.h
@@ -8,12 +8,15 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+// constants shared by all paths (C, SSE2).
+extern float rdft_w[64];
+
 // code path selection function pointers
-typedef void (*rft_sub_128_t)(float *a, float *c);
+typedef void (*rft_sub_128_t)(float *a);
 extern rft_sub_128_t rftfsub_128;
 extern rft_sub_128_t rftbsub_128;
 
 // entry points
 void aec_rdft_init(void);
 void aec_rdft_init_sse2(void);
-void aec_rdft_128(int, float *, int *, float *);
+void aec_rdft_128(int isgn, float *a);
diff --git a/modules/audio_processing/aec/main/source/aec_rdft_sse2.c b/modules/audio_processing/aec/main/source/aec_rdft_sse2.c
index df76aa3f2..901a1b146 100644
--- a/modules/audio_processing/aec/main/source/aec_rdft_sse2.c
+++ b/modules/audio_processing/aec/main/source/aec_rdft_sse2.c
@@ -20,7 +20,8 @@
 # define ALIGN16_END __attribute__((aligned(16)))
 #endif
 
-static void rftfsub_128_SSE2(float *a, float *c) {
+static void rftfsub_128_SSE2(float *a) {
+  const float *c = rdft_w + 32;
   int j1, j2, k1, k2;
   float wkr, wki, xr, xi, yr, yi;
 
@@ -109,7 +110,8 @@ static void rftfsub_128_SSE2(float *a, float *c) {
   }
 }
 
-static void rftbsub_128_SSE2(float *a, float *c) {
+static void rftbsub_128_SSE2(float *a) {
+  const float *c = rdft_w + 32;
   int j1, j2, k1, k2;
   float wkr, wki, xr, xi, yr, yi;