Add rounding to InterpolateRow for improved quality and consistency.

source/scale_argb.cc

 /*
  *  Copyright 2011 The LibYuv 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 192 matching lines @@
   int clip_src_width;
   xl = (xl >> 16) & ~3;  // Left edge aligned.
   xr = (xr >> 16) + 1;  // Right most pixel used.  Bilinear uses 2 pixels.
   xr = (xr + 1 + 3) & ~3;  // 1 beyond 4 pixel aligned right most pixel.
   if (xr > src_width) {
     xr = src_width;
   }
   clip_src_width = (int)(xr - xl) * 4;  // Width aligned to 4.
   src_argb += xl * 4;
   x -= (int)(xl << 16);
-#if defined(HAS_INTERPOLATEROW_SSE2)
-  if (TestCpuFlag(kCpuHasSSE2)) {
-    InterpolateRow = InterpolateRow_Any_SSE2;
-    if (IS_ALIGNED(clip_src_width, 16)) {
-      InterpolateRow = InterpolateRow_SSE2;
-    }
-  }
-#endif
 #if defined(HAS_INTERPOLATEROW_SSSE3)
   if (TestCpuFlag(kCpuHasSSSE3)) {
     InterpolateRow = InterpolateRow_Any_SSSE3;
     if (IS_ALIGNED(clip_src_width, 16)) {
       InterpolateRow = InterpolateRow_SSSE3;
     }
   }
 #endif
 #if defined(HAS_INTERPOLATEROW_AVX2)
   if (TestCpuFlag(kCpuHasAVX2)) {
@@ skipping 70 matching lines @@
                                 int x, int dx, int y, int dy,
                                 enum FilterMode filtering) {
   int j;
   void (*InterpolateRow)(uint8* dst_argb, const uint8* src_argb,
       ptrdiff_t src_stride, int dst_width, int source_y_fraction) =
       InterpolateRow_C;
   void (*ScaleARGBFilterCols)(uint8* dst_argb, const uint8* src_argb,
       int dst_width, int x, int dx) =
       filtering ? ScaleARGBFilterCols_C : ScaleARGBCols_C;
   const int max_y = (src_height - 1) << 16;
-#if defined(HAS_INTERPOLATEROW_SSE2)
-  if (TestCpuFlag(kCpuHasSSE2)) {
-    InterpolateRow = InterpolateRow_Any_SSE2;
-    if (IS_ALIGNED(dst_width, 4)) {
-      InterpolateRow = InterpolateRow_SSE2;
-    }
-  }
-#endif
 #if defined(HAS_INTERPOLATEROW_SSSE3)
   if (TestCpuFlag(kCpuHasSSSE3)) {
     InterpolateRow = InterpolateRow_Any_SSSE3;
     if (IS_ALIGNED(dst_width, 4)) {
       InterpolateRow = InterpolateRow_SSSE3;
     }
   }
 #endif
 #if defined(HAS_INTERPOLATEROW_AVX2)
   if (TestCpuFlag(kCpuHasAVX2)) {
@@ skipping 158 matching lines @@
       IS_ALIGNED(src_u, 2) && IS_ALIGNED(src_stride_u, 2) &&
       IS_ALIGNED(src_v, 2) && IS_ALIGNED(src_stride_v, 2) &&
       IS_ALIGNED(dst_argb, 4) && IS_ALIGNED(dst_stride_argb, 4)) {
     I422ToARGBRow = I422ToARGBRow_MIPS_DSPR2;
   }
 #endif
 
   void (*InterpolateRow)(uint8* dst_argb, const uint8* src_argb,
       ptrdiff_t src_stride, int dst_width, int source_y_fraction) =
       InterpolateRow_C;
-#if defined(HAS_INTERPOLATEROW_SSE2)
-  if (TestCpuFlag(kCpuHasSSE2)) {
-    InterpolateRow = InterpolateRow_Any_SSE2;
-    if (IS_ALIGNED(dst_width, 4)) {
-      InterpolateRow = InterpolateRow_SSE2;
-    }
-  }
-#endif
 #if defined(HAS_INTERPOLATEROW_SSSE3)
   if (TestCpuFlag(kCpuHasSSSE3)) {
     InterpolateRow = InterpolateRow_Any_SSSE3;
     if (IS_ALIGNED(dst_width, 4)) {
       InterpolateRow = InterpolateRow_SSSE3;
     }
   }
 #endif
 #if defined(HAS_INTERPOLATEROW_AVX2)
   if (TestCpuFlag(kCpuHasAVX2)) {
@@ skipping 360 matching lines @@
                     clip_x, clip_y, clip_width, clip_height,
                     filtering);
   free(argb_buffer);
   return r;
 }
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif