diff --git a/av1/av1_cx.mk b/av1/av1_cx.mk
index 0a0d770ce..f61d0aa8b 100644
--- a/av1/av1_cx.mk
+++ b/av1/av1_cx.mk
@@ -38,6 +38,7 @@ AV1_CX_SRCS-yes += encoder/ethread.h
 AV1_CX_SRCS-yes += encoder/ethread.c
 AV1_CX_SRCS-yes += encoder/extend.c
 AV1_CX_SRCS-yes += encoder/firstpass.c
+AV1_CX_SRCS-yes += encoder/mathutils.h
 AV1_CX_SRCS-$(CONFIG_GLOBAL_MOTION) += ../third_party/fastfeat/fast.h
 AV1_CX_SRCS-$(CONFIG_GLOBAL_MOTION) += ../third_party/fastfeat/nonmax.c
 AV1_CX_SRCS-$(CONFIG_GLOBAL_MOTION) += ../third_party/fastfeat/fast_9.c
diff --git a/av1/encoder/mathutils.h b/av1/encoder/mathutils.h
new file mode 100644
index 000000000..23243dd9e
--- /dev/null
+++ b/av1/encoder/mathutils.h
@@ -0,0 +1,354 @@
+/*
+ * Copyright (c) 2017, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include <memory.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+static const double TINY_NEAR_ZERO = 1.0E-16;
+
+// Solves Ax = b, where x and b are column vectors of size nx1 and A is nxn
+static INLINE int linsolve(int n, double *A, int stride, double *b, double *x) {
+  int i, j, k;
+  double c;
+  // Forward elimination
+  for (k = 0; k < n - 1; k++) {
+    // Bring the largest magitude to the diagonal position
+    for (i = n - 1; i > k; i--) {
+      if (fabs(A[(i - 1) * stride + k]) < fabs(A[i * stride + k])) {
+        for (j = 0; j < n; j++) {
+          c = A[i * stride + j];
+          A[i * stride + j] = A[(i - 1) * stride + j];
+          A[(i - 1) * stride + j] = c;
+        }
+        c = b[i];
+        b[i] = b[i - 1];
+        b[i - 1] = c;
+      }
+    }
+    for (i = k; i < n - 1; i++) {
+      if (fabs(A[k * stride + k]) < TINY_NEAR_ZERO) return 0;
+      c = A[(i + 1) * stride + k] / A[k * stride + k];
+      for (j = 0; j < n; j++) A[(i + 1) * stride + j] -= c * A[k * stride + j];
+      b[i + 1] -= c * b[k];
+    }
+  }
+  // Backward substitution
+  for (i = n - 1; i >= 0; i--) {
+    if (fabs(A[i * stride + i]) < TINY_NEAR_ZERO) return 0;
+    c = 0;
+    for (j = i + 1; j <= n - 1; j++) c += A[i * stride + j] * x[j];
+    x[i] = (b[i] - c) / A[i * stride + i];
+  }
+
+  return 1;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Least-squares
+// Solves for n-dim x in a least squares sense to minimize |Ax - b|^2
+// The solution is simply x = (A'A)^-1 A'b or simply the solution for
+// the system: A'A x = A'b
+static INLINE int least_squares(int n, double *A, int rows, int stride,
+                                double *b, double *scratch, double *x) {
+  int i, j, k;
+  double *scratch_ = NULL;
+  double *AtA, *Atb;
+  if (!scratch) {
+    scratch_ = (double *)aom_malloc(sizeof(*scratch) * n * (n + 1));
+    scratch = scratch_;
+  }
+  AtA = scratch;
+  Atb = scratch + n * n;
+
+  for (i = 0; i < n; ++i) {
+    for (j = i; j < n; ++j) {
+      AtA[i * n + j] = 0.0;
+      for (k = 0; k < rows; ++k)
+        AtA[i * n + j] += A[k * stride + i] * A[k * stride + j];
+      AtA[j * n + i] = AtA[i * n + j];
+    }
+    Atb[i] = 0;
+    for (k = 0; k < rows; ++k) Atb[i] += A[k * stride + i] * b[k];
+  }
+  int ret = linsolve(n, AtA, n, Atb, x);
+  if (scratch_) aom_free(scratch_);
+  return ret;
+}
+
+// Matrix multiply
+static INLINE void multiply_mat(const double *m1, const double *m2, double *res,
+                                const int m1_rows, const int inner_dim,
+                                const int m2_cols) {
+  double sum;
+
+  int row, col, inner;
+  for (row = 0; row < m1_rows; ++row) {
+    for (col = 0; col < m2_cols; ++col) {
+      sum = 0;
+      for (inner = 0; inner < inner_dim; ++inner)
+        sum += m1[row * inner_dim + inner] * m2[inner * m2_cols + col];
+      *(res++) = sum;
+    }
+  }
+}
+
+//
+// The functions below are needed only for homography computation
+// Remove if the homography models are not used.
+//
+///////////////////////////////////////////////////////////////////////////////
+// svdcmp
+// Adopted from Numerical Recipes in C
+
+static INLINE double sign(double a, double b) {
+  return ((b) >= 0 ? fabs(a) : -fabs(a));
+}
+
+static INLINE double pythag(double a, double b) {
+  double ct;
+  const double absa = fabs(a);
+  const double absb = fabs(b);
+
+  if (absa > absb) {
+    ct = absb / absa;
+    return absa * sqrt(1.0 + ct * ct);
+  } else {
+    ct = absa / absb;
+    return (absb == 0) ? 0 : absb * sqrt(1.0 + ct * ct);
+  }
+}
+
+static INLINE int svdcmp(double **u, int m, int n, double w[], double **v) {
+  const int max_its = 30;
+  int flag, i, its, j, jj, k, l, nm;
+  double anorm, c, f, g, h, s, scale, x, y, z;
+  double *rv1 = (double *)aom_malloc(sizeof(*rv1) * (n + 1));
+  g = scale = anorm = 0.0;
+  for (i = 0; i < n; i++) {
+    l = i + 1;
+    rv1[i] = scale * g;
+    g = s = scale = 0.0;
+    if (i < m) {
+      for (k = i; k < m; k++) scale += fabs(u[k][i]);
+      if (scale != 0.) {
+        for (k = i; k < m; k++) {
+          u[k][i] /= scale;
+          s += u[k][i] * u[k][i];
+        }
+        f = u[i][i];
+        g = -sign(sqrt(s), f);
+        h = f * g - s;
+        u[i][i] = f - g;
+        for (j = l; j < n; j++) {
+          for (s = 0.0, k = i; k < m; k++) s += u[k][i] * u[k][j];
+          f = s / h;
+          for (k = i; k < m; k++) u[k][j] += f * u[k][i];
+        }
+        for (k = i; k < m; k++) u[k][i] *= scale;
+      }
+    }
+    w[i] = scale * g;
+    g = s = scale = 0.0;
+    if (i < m && i != n - 1) {
+      for (k = l; k < n; k++) scale += fabs(u[i][k]);
+      if (scale != 0.) {
+        for (k = l; k < n; k++) {
+          u[i][k] /= scale;
+          s += u[i][k] * u[i][k];
+        }
+        f = u[i][l];
+        g = -sign(sqrt(s), f);
+        h = f * g - s;
+        u[i][l] = f - g;
+        for (k = l; k < n; k++) rv1[k] = u[i][k] / h;
+        for (j = l; j < m; j++) {
+          for (s = 0.0, k = l; k < n; k++) s += u[j][k] * u[i][k];
+          for (k = l; k < n; k++) u[j][k] += s * rv1[k];
+        }
+        for (k = l; k < n; k++) u[i][k] *= scale;
+      }
+    }
+    anorm = fmax(anorm, (fabs(w[i]) + fabs(rv1[i])));
+  }
+
+  for (i = n - 1; i >= 0; i--) {
+    if (i < n - 1) {
+      if (g != 0.) {
+        for (j = l; j < n; j++) v[j][i] = (u[i][j] / u[i][l]) / g;
+        for (j = l; j < n; j++) {
+          for (s = 0.0, k = l; k < n; k++) s += u[i][k] * v[k][j];
+          for (k = l; k < n; k++) v[k][j] += s * v[k][i];
+        }
+      }
+      for (j = l; j < n; j++) v[i][j] = v[j][i] = 0.0;
+    }
+    v[i][i] = 1.0;
+    g = rv1[i];
+    l = i;
+  }
+  for (i = AOMMIN(m, n) - 1; i >= 0; i--) {
+    l = i + 1;
+    g = w[i];
+    for (j = l; j < n; j++) u[i][j] = 0.0;
+    if (g != 0.) {
+      g = 1.0 / g;
+      for (j = l; j < n; j++) {
+        for (s = 0.0, k = l; k < m; k++) s += u[k][i] * u[k][j];
+        f = (s / u[i][i]) * g;
+        for (k = i; k < m; k++) u[k][j] += f * u[k][i];
+      }
+      for (j = i; j < m; j++) u[j][i] *= g;
+    } else {
+      for (j = i; j < m; j++) u[j][i] = 0.0;
+    }
+    ++u[i][i];
+  }
+  for (k = n - 1; k >= 0; k--) {
+    for (its = 0; its < max_its; its++) {
+      flag = 1;
+      for (l = k; l >= 0; l--) {
+        nm = l - 1;
+        if ((double)(fabs(rv1[l]) + anorm) == anorm || nm < 0) {
+          flag = 0;
+          break;
+        }
+        if ((double)(fabs(w[nm]) + anorm) == anorm) break;
+      }
+      if (flag) {
+        c = 0.0;
+        s = 1.0;
+        for (i = l; i <= k; i++) {
+          f = s * rv1[i];
+          rv1[i] = c * rv1[i];
+          if ((double)(fabs(f) + anorm) == anorm) break;
+          g = w[i];
+          h = pythag(f, g);
+          w[i] = h;
+          h = 1.0 / h;
+          c = g * h;
+          s = -f * h;
+          for (j = 0; j < m; j++) {
+            y = u[j][nm];
+            z = u[j][i];
+            u[j][nm] = y * c + z * s;
+            u[j][i] = z * c - y * s;
+          }
+        }
+      }
+      z = w[k];
+      if (l == k) {
+        if (z < 0.0) {
+          w[k] = -z;
+          for (j = 0; j < n; j++) v[j][k] = -v[j][k];
+        }
+        break;
+      }
+      if (its == max_its - 1) {
+        aom_free(rv1);
+        return 1;
+      }
+      assert(k > 0);
+      x = w[l];
+      nm = k - 1;
+      y = w[nm];
+      g = rv1[nm];
+      h = rv1[k];
+      f = ((y - z) * (y + z) + (g - h) * (g + h)) / (2.0 * h * y);
+      g = pythag(f, 1.0);
+      f = ((x - z) * (x + z) + h * ((y / (f + sign(g, f))) - h)) / x;
+      c = s = 1.0;
+      for (j = l; j <= nm; j++) {
+        i = j + 1;
+        g = rv1[i];
+        y = w[i];
+        h = s * g;
+        g = c * g;
+        z = pythag(f, h);
+        rv1[j] = z;
+        c = f / z;
+        s = h / z;
+        f = x * c + g * s;
+        g = g * c - x * s;
+        h = y * s;
+        y *= c;
+        for (jj = 0; jj < n; jj++) {
+          x = v[jj][j];
+          z = v[jj][i];
+          v[jj][j] = x * c + z * s;
+          v[jj][i] = z * c - x * s;
+        }
+        z = pythag(f, h);
+        w[j] = z;
+        if (z != 0.) {
+          z = 1.0 / z;
+          c = f * z;
+          s = h * z;
+        }
+        f = c * g + s * y;
+        x = c * y - s * g;
+        for (jj = 0; jj < m; jj++) {
+          y = u[jj][j];
+          z = u[jj][i];
+          u[jj][j] = y * c + z * s;
+          u[jj][i] = z * c - y * s;
+        }
+      }
+      rv1[l] = 0.0;
+      rv1[k] = f;
+      w[k] = x;
+    }
+  }
+  aom_free(rv1);
+  return 0;
+}
+
+static INLINE int SVD(double *U, double *W, double *V, double *matx, int M,
+                      int N) {
+  // Assumes allocation for U is MxN
+  double **nrU = (double **)aom_malloc((M) * sizeof(*nrU));
+  double **nrV = (double **)aom_malloc((N) * sizeof(*nrV));
+  int problem, i;
+
+  problem = !(nrU && nrV);
+  if (!problem) {
+    for (i = 0; i < M; i++) {
+      nrU[i] = &U[i * N];
+    }
+    for (i = 0; i < N; i++) {
+      nrV[i] = &V[i * N];
+    }
+  } else {
+    if (nrU) aom_free(nrU);
+    if (nrV) aom_free(nrV);
+    return 1;
+  }
+
+  /* copy from given matx into nrU */
+  for (i = 0; i < M; i++) {
+    memcpy(&(nrU[i][0]), matx + N * i, N * sizeof(*matx));
+  }
+
+  /* HERE IT IS: do SVD */
+  if (svdcmp(nrU, M, N, W, nrV)) {
+    aom_free(nrU);
+    aom_free(nrV);
+    return 1;
+  }
+
+  /* aom_free Numerical Recipes arrays */
+  aom_free(nrU);
+  aom_free(nrV);
+
+  return 0;
+}
diff --git a/av1/encoder/pickrst.c b/av1/encoder/pickrst.c
index 21410e0af..0cd72c0c7 100644
--- a/av1/encoder/pickrst.c
+++ b/av1/encoder/pickrst.c
@@ -31,6 +31,7 @@
 #include "av1/encoder/encoder.h"
 #include "av1/encoder/picklpf.h"
 #include "av1/encoder/pickrst.h"
+#include "av1/encoder/mathutils.h"
 
 // When set to RESTORE_WIENER or RESTORE_SGRPROJ only those are allowed.
 // When set to RESTORE_NONE (0) we allow switchable.
@@ -329,8 +330,10 @@ static void search_selfguided_restoration(uint8_t *dat8, int width, int height,
 #if CONFIG_HIGHBITDEPTH
     }
 #endif
+    aom_clear_system_state();
     get_proj_subspace(src8, width, height, src_stride, dat8, dat_stride,
                       bit_depth, flt1, width, flt2, width, exq);
+    aom_clear_system_state();
     encode_xq(exq, exqd);
     err =
         get_pixel_proj_error(src8, width, height, src_stride, dat8, dat_stride,
@@ -560,46 +563,6 @@ static void compute_stats_highbd(uint8_t *dgd8, uint8_t *src8, int h_start,
 }
 #endif  // CONFIG_HIGHBITDEPTH
 
-// Solves Ax = b, where x and b are column vectors
-static int linsolve(int n, double *A, int stride, double *b, double *x) {
-  int i, j, k;
-  double c;
-
-  aom_clear_system_state();
-
-  // Forward elimination
-  for (k = 0; k < n - 1; k++) {
-    // Bring the largest magitude to the diagonal position
-    for (i = n - 1; i > k; i--) {
-      if (fabs(A[(i - 1) * stride + k]) < fabs(A[i * stride + k])) {
-        for (j = 0; j < n; j++) {
-          c = A[i * stride + j];
-          A[i * stride + j] = A[(i - 1) * stride + j];
-          A[(i - 1) * stride + j] = c;
-        }
-        c = b[i];
-        b[i] = b[i - 1];
-        b[i - 1] = c;
-      }
-    }
-    for (i = k; i < n - 1; i++) {
-      if (fabs(A[k * stride + k]) < 1e-10) return 0;
-      c = A[(i + 1) * stride + k] / A[k * stride + k];
-      for (j = 0; j < n; j++) A[(i + 1) * stride + j] -= c * A[k * stride + j];
-      b[i + 1] -= c * b[k];
-    }
-  }
-  // Backward substitution
-  for (i = n - 1; i >= 0; i--) {
-    if (fabs(A[i * stride + i]) < 1e-10) return 0;
-    c = 0;
-    for (j = i + 1; j <= n - 1; j++) c += A[i * stride + j] * x[j];
-    x[i] = (b[i] - c) / A[i * stride + i];
-  }
-
-  return 1;
-}
-
 static INLINE int wrap_index(int i) {
   return (i >= WIENER_HALFWIN1 ? WIENER_WIN - 1 - i : i);
 }
@@ -910,6 +873,7 @@ static double search_wiener_uv(const YV12_BUFFER_CONFIG *src, AV1_COMP *cpi,
       type[tile_idx] = RESTORE_NONE;
       continue;
     }
+    aom_clear_system_state();
 
     rsi[plane].restoration_type[tile_idx] = RESTORE_WIENER;
     err = try_restoration_tile(src, cpi, rsi, 1 << plane, partial_frame,
@@ -1052,6 +1016,7 @@ static double search_wiener(const YV12_BUFFER_CONFIG *src, AV1_COMP *cpi,
       type[tile_idx] = RESTORE_NONE;
       continue;
     }
+    aom_clear_system_state();
 
     rsi->restoration_type[tile_idx] = RESTORE_WIENER;
     err = try_restoration_tile(src, cpi, rsi, 1, partial_frame, tile_idx, 0, 0,
diff --git a/av1/encoder/ransac.c b/av1/encoder/ransac.c
index f7188f1fe..b9b1d3b2c 100644
--- a/av1/encoder/ransac.c
+++ b/av1/encoder/ransac.c
@@ -16,6 +16,7 @@
 #include <assert.h>
 
 #include "av1/encoder/ransac.h"
+#include "av1/encoder/mathutils.h"
 
 #define MAX_MINPTS 4
 #define MAX_DEGENERATE_ITER 10
@@ -132,309 +133,6 @@ static void project_points_double_homography(double *mat, double *points,
   }
 }
 
-///////////////////////////////////////////////////////////////////////////////
-// svdcmp
-// Adopted from Numerical Recipes in C
-
-static const double TINY_NEAR_ZERO = 1.0E-12;
-
-static INLINE double sign(double a, double b) {
-  return ((b) >= 0 ? fabs(a) : -fabs(a));
-}
-
-static INLINE double pythag(double a, double b) {
-  double ct;
-  const double absa = fabs(a);
-  const double absb = fabs(b);
-
-  if (absa > absb) {
-    ct = absb / absa;
-    return absa * sqrt(1.0 + ct * ct);
-  } else {
-    ct = absa / absb;
-    return (absb == 0) ? 0 : absb * sqrt(1.0 + ct * ct);
-  }
-}
-
-static void multiply_mat(const double *m1, const double *m2, double *res,
-                         const int m1_rows, const int inner_dim,
-                         const int m2_cols) {
-  double sum;
-
-  int row, col, inner;
-  for (row = 0; row < m1_rows; ++row) {
-    for (col = 0; col < m2_cols; ++col) {
-      sum = 0;
-      for (inner = 0; inner < inner_dim; ++inner)
-        sum += m1[row * inner_dim + inner] * m2[inner * m2_cols + col];
-      *(res++) = sum;
-    }
-  }
-}
-
-static int svdcmp(double **u, int m, int n, double w[], double **v) {
-  const int max_its = 30;
-  int flag, i, its, j, jj, k, l, nm;
-  double anorm, c, f, g, h, s, scale, x, y, z;
-  double *rv1 = (double *)aom_malloc(sizeof(*rv1) * (n + 1));
-  g = scale = anorm = 0.0;
-  for (i = 0; i < n; i++) {
-    l = i + 1;
-    rv1[i] = scale * g;
-    g = s = scale = 0.0;
-    if (i < m) {
-      for (k = i; k < m; k++) scale += fabs(u[k][i]);
-      if (scale != 0.) {
-        for (k = i; k < m; k++) {
-          u[k][i] /= scale;
-          s += u[k][i] * u[k][i];
-        }
-        f = u[i][i];
-        g = -sign(sqrt(s), f);
-        h = f * g - s;
-        u[i][i] = f - g;
-        for (j = l; j < n; j++) {
-          for (s = 0.0, k = i; k < m; k++) s += u[k][i] * u[k][j];
-          f = s / h;
-          for (k = i; k < m; k++) u[k][j] += f * u[k][i];
-        }
-        for (k = i; k < m; k++) u[k][i] *= scale;
-      }
-    }
-    w[i] = scale * g;
-    g = s = scale = 0.0;
-    if (i < m && i != n - 1) {
-      for (k = l; k < n; k++) scale += fabs(u[i][k]);
-      if (scale != 0.) {
-        for (k = l; k < n; k++) {
-          u[i][k] /= scale;
-          s += u[i][k] * u[i][k];
-        }
-        f = u[i][l];
-        g = -sign(sqrt(s), f);
-        h = f * g - s;
-        u[i][l] = f - g;
-        for (k = l; k < n; k++) rv1[k] = u[i][k] / h;
-        for (j = l; j < m; j++) {
-          for (s = 0.0, k = l; k < n; k++) s += u[j][k] * u[i][k];
-          for (k = l; k < n; k++) u[j][k] += s * rv1[k];
-        }
-        for (k = l; k < n; k++) u[i][k] *= scale;
-      }
-    }
-    anorm = fmax(anorm, (fabs(w[i]) + fabs(rv1[i])));
-  }
-
-  for (i = n - 1; i >= 0; i--) {
-    if (i < n - 1) {
-      if (g != 0.) {
-        for (j = l; j < n; j++) v[j][i] = (u[i][j] / u[i][l]) / g;
-        for (j = l; j < n; j++) {
-          for (s = 0.0, k = l; k < n; k++) s += u[i][k] * v[k][j];
-          for (k = l; k < n; k++) v[k][j] += s * v[k][i];
-        }
-      }
-      for (j = l; j < n; j++) v[i][j] = v[j][i] = 0.0;
-    }
-    v[i][i] = 1.0;
-    g = rv1[i];
-    l = i;
-  }
-  for (i = AOMMIN(m, n) - 1; i >= 0; i--) {
-    l = i + 1;
-    g = w[i];
-    for (j = l; j < n; j++) u[i][j] = 0.0;
-    if (g != 0.) {
-      g = 1.0 / g;
-      for (j = l; j < n; j++) {
-        for (s = 0.0, k = l; k < m; k++) s += u[k][i] * u[k][j];
-        f = (s / u[i][i]) * g;
-        for (k = i; k < m; k++) u[k][j] += f * u[k][i];
-      }
-      for (j = i; j < m; j++) u[j][i] *= g;
-    } else {
-      for (j = i; j < m; j++) u[j][i] = 0.0;
-    }
-    ++u[i][i];
-  }
-  for (k = n - 1; k >= 0; k--) {
-    for (its = 0; its < max_its; its++) {
-      flag = 1;
-      for (l = k; l >= 0; l--) {
-        nm = l - 1;
-        if ((double)(fabs(rv1[l]) + anorm) == anorm || nm < 0) {
-          flag = 0;
-          break;
-        }
-        if ((double)(fabs(w[nm]) + anorm) == anorm) break;
-      }
-      if (flag) {
-        c = 0.0;
-        s = 1.0;
-        for (i = l; i <= k; i++) {
-          f = s * rv1[i];
-          rv1[i] = c * rv1[i];
-          if ((double)(fabs(f) + anorm) == anorm) break;
-          g = w[i];
-          h = pythag(f, g);
-          w[i] = h;
-          h = 1.0 / h;
-          c = g * h;
-          s = -f * h;
-          for (j = 0; j < m; j++) {
-            y = u[j][nm];
-            z = u[j][i];
-            u[j][nm] = y * c + z * s;
-            u[j][i] = z * c - y * s;
-          }
-        }
-      }
-      z = w[k];
-      if (l == k) {
-        if (z < 0.0) {
-          w[k] = -z;
-          for (j = 0; j < n; j++) v[j][k] = -v[j][k];
-        }
-        break;
-      }
-      if (its == max_its - 1) {
-        aom_free(rv1);
-        return 1;
-      }
-      assert(k > 0);
-      x = w[l];
-      nm = k - 1;
-      y = w[nm];
-      g = rv1[nm];
-      h = rv1[k];
-      f = ((y - z) * (y + z) + (g - h) * (g + h)) / (2.0 * h * y);
-      g = pythag(f, 1.0);
-      f = ((x - z) * (x + z) + h * ((y / (f + sign(g, f))) - h)) / x;
-      c = s = 1.0;
-      for (j = l; j <= nm; j++) {
-        i = j + 1;
-        g = rv1[i];
-        y = w[i];
-        h = s * g;
-        g = c * g;
-        z = pythag(f, h);
-        rv1[j] = z;
-        c = f / z;
-        s = h / z;
-        f = x * c + g * s;
-        g = g * c - x * s;
-        h = y * s;
-        y *= c;
-        for (jj = 0; jj < n; jj++) {
-          x = v[jj][j];
-          z = v[jj][i];
-          v[jj][j] = x * c + z * s;
-          v[jj][i] = z * c - x * s;
-        }
-        z = pythag(f, h);
-        w[j] = z;
-        if (z != 0.) {
-          z = 1.0 / z;
-          c = f * z;
-          s = h * z;
-        }
-        f = c * g + s * y;
-        x = c * y - s * g;
-        for (jj = 0; jj < m; jj++) {
-          y = u[jj][j];
-          z = u[jj][i];
-          u[jj][j] = y * c + z * s;
-          u[jj][i] = z * c - y * s;
-        }
-      }
-      rv1[l] = 0.0;
-      rv1[k] = f;
-      w[k] = x;
-    }
-  }
-  aom_free(rv1);
-  return 0;
-}
-
-static int SVD(double *U, double *W, double *V, double *matx, int M, int N) {
-  // Assumes allocation for U is MxN
-  double **nrU = (double **)aom_malloc((M) * sizeof(*nrU));
-  double **nrV = (double **)aom_malloc((N) * sizeof(*nrV));
-  int problem, i;
-
-  problem = !(nrU && nrV);
-  if (!problem) {
-    for (i = 0; i < M; i++) {
-      nrU[i] = &U[i * N];
-    }
-    for (i = 0; i < N; i++) {
-      nrV[i] = &V[i * N];
-    }
-  } else {
-    if (nrU) aom_free(nrU);
-    if (nrV) aom_free(nrV);
-    return 1;
-  }
-
-  /* copy from given matx into nrU */
-  for (i = 0; i < M; i++) {
-    memcpy(&(nrU[i][0]), matx + N * i, N * sizeof(*matx));
-  }
-
-  /* HERE IT IS: do SVD */
-  if (svdcmp(nrU, M, N, W, nrV)) {
-    aom_free(nrU);
-    aom_free(nrV);
-    return 1;
-  }
-
-  /* aom_free Numerical Recipes arrays */
-  aom_free(nrU);
-  aom_free(nrV);
-
-  return 0;
-}
-
-int pseudo_inverse(double *inv, double *matx, const int M, const int N) {
-  double ans;
-  int i, j, k;
-  double *const U = (double *)aom_malloc(M * N * sizeof(*matx));
-  double *const W = (double *)aom_malloc(N * sizeof(*matx));
-  double *const V = (double *)aom_malloc(N * N * sizeof(*matx));
-
-  if (!(U && W && V)) {
-    return 1;
-  }
-  if (SVD(U, W, V, matx, M, N)) {
-    aom_free(U);
-    aom_free(W);
-    aom_free(V);
-    return 1;
-  }
-  for (i = 0; i < N; i++) {
-    if (fabs(W[i]) < TINY_NEAR_ZERO) {
-      aom_free(U);
-      aom_free(W);
-      aom_free(V);
-      return 1;
-    }
-  }
-
-  for (i = 0; i < N; i++) {
-    for (j = 0; j < M; j++) {
-      ans = 0;
-      for (k = 0; k < N; k++) {
-        ans += V[k + N * i] * U[k + N * j] / W[k];
-      }
-      inv[j + M * i] = ans;
-    }
-  }
-  aom_free(U);
-  aom_free(W);
-  aom_free(V);
-  return 0;
-}
-
 static void normalize_homography(double *pts, int n, double *T) {
   double *p = pts;
   double mean[2] = { 0, 0 };
@@ -596,7 +294,7 @@ static int find_translation(int np, double *pts1, double *pts2, double *mat) {
 
 static int find_rotzoom(int np, double *pts1, double *pts2, double *mat) {
   const int np2 = np * 2;
-  double *a = (double *)aom_malloc(sizeof(*a) * np2 * 9);
+  double *a = (double *)aom_malloc(sizeof(*a) * np2 * 10);
   double *b = a + np2 * 4;
   double *temp = b + np2;
   int i;
@@ -624,11 +322,10 @@ static int find_rotzoom(int np, double *pts1, double *pts2, double *mat) {
     b[2 * i] = dx;
     b[2 * i + 1] = dy;
   }
-  if (pseudo_inverse(temp, a, np2, 4)) {
+  if (!least_squares(4, a, np2, 4, b, temp, mat)) {
     aom_free(a);
     return 1;
   }
-  multiply_mat(temp, b, mat, 4, np2, 1);
   denormalize_rotzoom_reorder(mat, T1, T2);
   aom_free(a);
   return 0;
@@ -636,7 +333,7 @@ static int find_rotzoom(int np, double *pts1, double *pts2, double *mat) {
 
 static int find_affine(int np, double *pts1, double *pts2, double *mat) {
   const int np2 = np * 2;
-  double *a = (double *)aom_malloc(sizeof(*a) * np2 * 13);
+  double *a = (double *)aom_malloc(sizeof(*a) * np2 * 14);
   double *b = a + np2 * 6;
   double *temp = b + np2;
   int i;
@@ -668,11 +365,10 @@ static int find_affine(int np, double *pts1, double *pts2, double *mat) {
     b[2 * i] = dx;
     b[2 * i + 1] = dy;
   }
-  if (pseudo_inverse(temp, a, np2, 6)) {
+  if (!least_squares(6, a, np2, 6, b, temp, mat)) {
     aom_free(a);
     return 1;
   }
-  multiply_mat(temp, b, mat, 6, np2, 1);
   denormalize_affine_reorder(mat, T1, T2);
   aom_free(a);
   return 0;