libvpx: Pull from upstream

source/libvpx/test/convolve_test.cc

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  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.
  */
 
@@ skipping 438 matching lines @@
     { 0,   0,   0,   0,   0,   0,   0, 128},
     { 0,   0,   0,   0,   0,   0, 128},
     { 0,   0,   0,   0,   0, 128},
     { 0,   0,   0,   0, 128},
     { 0,   0,   0, 128},
     { 0,   0, 128},
     { 0, 128},
     { 128}
 };
 
+/* This test exercises the horizontal and vertical filter functions. */
 TEST_P(ConvolveTest, ChangeFilterWorks) {
   uint8_t* const in = input();
   uint8_t* const out = output();
+
+  /* Assume that the first input sample is at the 8/16th position. */
+  const int kInitialSubPelOffset = 8;
+
+  /* Filters are 8-tap, so the first filter tap will be applied to the pixel
+   * at position -3 with respect to the current filtering position. Since
+   * kInitialSubPelOffset is set to 8, we first select sub-pixel filter 8,
+   * which is non-zero only in the last tap. So, applying the filter at the
+   * current input position will result in an output equal to the pixel at
+   * offset +4 (-3 + 7) with respect to the current filtering position.
+   */
   const int kPixelSelected = 4;
 
+  /* Assume that each output pixel requires us to step on by 17/16th pixels in
+   * the input.
+   */
+  const int kInputPixelStep = 17;
+
+  /* The filters are setup in such a way that the expected output produces
+   * sets of 8 identical output samples. As the filter position moves to the
+   * next 1/16th pixel position the only active (=128) filter tap moves one
+   * position to the left, resulting in the same input pixel being replicated
+   * in to the output for 8 consecutive samples. After each set of 8 positions
+   * the filters select a different input pixel. kFilterPeriodAdjust below
+   * computes which input pixel is written to the output for a specified
+   * x or y position.
+   */
+
+  /* Test the horizontal filter. */
   REGISTER_STATE_CHECK(UUT_->h8_(in, kInputStride, out, kOutputStride,
-                                 kChangeFilters[8], 17, kChangeFilters[4], 16,
-                                 Width(), Height()));
+                                 kChangeFilters[kInitialSubPelOffset],
+                                 kInputPixelStep, NULL, 0, Width(), Height()));
 
   for (int x = 0; x < Width(); ++x) {
-    const int kQ4StepAdjust = x >> 4;
     const int kFilterPeriodAdjust = (x >> 3) << 3;
-    const int ref_x = kQ4StepAdjust + kFilterPeriodAdjust + kPixelSelected;
-    ASSERT_EQ(in[ref_x], out[x]) << "x == " << x;
+    const int ref_x =
+        kPixelSelected + ((kInitialSubPelOffset
+            + kFilterPeriodAdjust * kInputPixelStep)
+                          >> SUBPEL_BITS);
+    ASSERT_EQ(in[ref_x], out[x]) << "x == " << x << "width = " << Width();
   }
 
+  /* Test the vertical filter. */
   REGISTER_STATE_CHECK(UUT_->v8_(in, kInputStride, out, kOutputStride,
-                                 kChangeFilters[4], 16, kChangeFilters[8], 17,
-                                 Width(), Height()));
+                                 NULL, 0, kChangeFilters[kInitialSubPelOffset],
+                                 kInputPixelStep, Width(), Height()));
 
   for (int y = 0; y < Height(); ++y) {
-    const int kQ4StepAdjust = y >> 4;
     const int kFilterPeriodAdjust = (y >> 3) << 3;
-    const int ref_y = kQ4StepAdjust + kFilterPeriodAdjust + kPixelSelected;
+    const int ref_y =
+        kPixelSelected + ((kInitialSubPelOffset
+            + kFilterPeriodAdjust * kInputPixelStep)
+                          >> SUBPEL_BITS);
     ASSERT_EQ(in[ref_y * kInputStride], out[y * kInputStride]) << "y == " << y;
   }
 
+  /* Test the horizontal and vertical filters in combination. */
   REGISTER_STATE_CHECK(UUT_->hv8_(in, kInputStride, out, kOutputStride,
-                                  kChangeFilters[8], 17, kChangeFilters[8], 17,
+                                  kChangeFilters[kInitialSubPelOffset],
+                                  kInputPixelStep,
+                                  kChangeFilters[kInitialSubPelOffset],
+                                  kInputPixelStep,
                                   Width(), Height()));
 
   for (int y = 0; y < Height(); ++y) {
-    const int kQ4StepAdjustY = y >> 4;
     const int kFilterPeriodAdjustY = (y >> 3) << 3;
-    const int ref_y = kQ4StepAdjustY + kFilterPeriodAdjustY + kPixelSelected;
+    const int ref_y =
+        kPixelSelected + ((kInitialSubPelOffset
+            + kFilterPeriodAdjustY * kInputPixelStep)
+                          >> SUBPEL_BITS);
     for (int x = 0; x < Width(); ++x) {
-      const int kQ4StepAdjustX = x >> 4;
       const int kFilterPeriodAdjustX = (x >> 3) << 3;
-      const int ref_x = kQ4StepAdjustX + kFilterPeriodAdjustX + kPixelSelected;
+      const int ref_x =
+          kPixelSelected + ((kInitialSubPelOffset
+              + kFilterPeriodAdjustX * kInputPixelStep)
+                            >> SUBPEL_BITS);
 
       ASSERT_EQ(in[ref_y * kInputStride + ref_x], out[y * kOutputStride + x])
           << "x == " << x << ", y == " << y;
     }
   }
 }
 
-
 using std::tr1::make_tuple;
 
 const ConvolveFunctions convolve8_c(
     vp9_convolve8_horiz_c, vp9_convolve8_avg_horiz_c,
     vp9_convolve8_vert_c, vp9_convolve8_avg_vert_c,
     vp9_convolve8_c, vp9_convolve8_avg_c);
 
 INSTANTIATE_TEST_CASE_P(C, ConvolveTest, ::testing::Values(
     make_tuple(4, 4, &convolve8_c),
     make_tuple(8, 4, &convolve8_c),
     make_tuple(4, 8, &convolve8_c),
     make_tuple(8, 8, &convolve8_c),
     make_tuple(16, 8, &convolve8_c),
     make_tuple(8, 16, &convolve8_c),
     make_tuple(16, 16, &convolve8_c),
     make_tuple(32, 16, &convolve8_c),
     make_tuple(16, 32, &convolve8_c),
     make_tuple(32, 32, &convolve8_c),
     make_tuple(64, 32, &convolve8_c),
     make_tuple(32, 64, &convolve8_c),
     make_tuple(64, 64, &convolve8_c)));
 
 #if HAVE_SSSE3
 const ConvolveFunctions convolve8_ssse3(
-    vp9_convolve8_horiz_ssse3, vp9_convolve8_avg_horiz_c,
-    vp9_convolve8_vert_ssse3, vp9_convolve8_avg_vert_c,
-    vp9_convolve8_ssse3, vp9_convolve8_avg_c);
+    vp9_convolve8_horiz_ssse3, vp9_convolve8_avg_horiz_ssse3,
+    vp9_convolve8_vert_ssse3, vp9_convolve8_avg_vert_ssse3,
+    vp9_convolve8_ssse3, vp9_convolve8_avg_ssse3);
 
 INSTANTIATE_TEST_CASE_P(SSSE3, ConvolveTest, ::testing::Values(
     make_tuple(4, 4, &convolve8_ssse3),
     make_tuple(8, 4, &convolve8_ssse3),
     make_tuple(4, 8, &convolve8_ssse3),
     make_tuple(8, 8, &convolve8_ssse3),
     make_tuple(16, 8, &convolve8_ssse3),
     make_tuple(8, 16, &convolve8_ssse3),
     make_tuple(16, 16, &convolve8_ssse3),
     make_tuple(32, 16, &convolve8_ssse3),
@@ skipping 19 matching lines @@
     make_tuple(8, 16, &convolve8_neon),
     make_tuple(16, 16, &convolve8_neon),
     make_tuple(32, 16, &convolve8_neon),
     make_tuple(16, 32, &convolve8_neon),
     make_tuple(32, 32, &convolve8_neon),
     make_tuple(64, 32, &convolve8_neon),
     make_tuple(32, 64, &convolve8_neon),
     make_tuple(64, 64, &convolve8_neon)));
 #endif
 }  // namespace