ARGB Scale ported to C

BUG=303
TESTED=cl /c /TC /Iinclude source/scale_argb.cc
R=tpsiaki@google.com

Review URL: https://webrtc-codereview.appspot.com/7169004

git-svn-id: http://libyuv.googlecode.com/svn/trunk@972 16f28f9a-4ce2-e073-06de-1de4eb20be90

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 971
+Version: 972
 License: BSD
 License File: LICENSE
 

include/libyuv/version.h

@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_  // NOLINT
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 971
+#define LIBYUV_VERSION 972
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT

source/scale_argb.cc

@@ -170,6 +170,12 @@ static void ScaleARGBBilinearDown(int src_width, int src_height,
                                   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) =
+      (src_width >= 32768) ? ScaleARGBFilterCols64_C : ScaleARGBFilterCols_C;
   int64 xlast = x + (int64)(dst_width - 1) * dx;
   int64 xl = (dx >= 0) ? x : xlast;
   int64 xr = (dx >= 0) ? xlast : x;
@@ -179,9 +185,6 @@ static void ScaleARGBBilinearDown(int src_width, int src_height,
   clip_src_width = (((xr - xl) + 1 + 3) & ~3) * 4;  // Width aligned to 4.
   src_argb += xl * 4;
   x -= (int)(xl << 16);
-  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) && clip_src_width >= 16) {
     InterpolateRow = InterpolateRow_Any_SSE2;
@@ -229,9 +232,6 @@ static void ScaleARGBBilinearDown(int src_width, int src_height,
     }
   }
 #endif
-  void (*ScaleARGBFilterCols)(uint8* dst_argb, const uint8* src_argb,
-      int dst_width, int x, int dx) =
-      (src_width >= 32768) ? ScaleARGBFilterCols64_C : ScaleARGBFilterCols_C;
 #if defined(HAS_SCALEARGBFILTERCOLS_SSSE3)
   if (TestCpuFlag(kCpuHasSSSE3) && src_width < 32768) {
     ScaleARGBFilterCols = ScaleARGBFilterCols_SSSE3;
@@ -239,13 +239,14 @@ static void ScaleARGBBilinearDown(int src_width, int src_height,
 #endif
   // TODO(fbarchard): Consider not allocating row buffer for kFilterLinear.
   // Allocate a row of ARGB.
+  {
     align_buffer_64(row, clip_src_width * 4);
 
     const int max_y = (src_height - 1) << 16;
-  for (j = 0; j < dst_height; ++j) {
     if (y > max_y) {
       y = max_y;
     }
+    for (j = 0; j < dst_height; ++j) {
       int yi = y >> 16;
       const uint8* src = src_argb + yi * src_stride;
       if (filtering == kFilterLinear) {
@@ -257,8 +258,12 @@ static void ScaleARGBBilinearDown(int src_width, int src_height,
       }
       dst_argb += dst_stride;
       y += dy;
+      if (y > max_y) {
+        y = max_y;
+      }
     }
     free_aligned_buffer_64(row);
+  }
 }
 
 // Scale ARGB up with bilinear interpolation.
@@ -275,6 +280,7 @@ static void ScaleARGBBilinearUp(int src_width, int src_height,
   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) && dst_width >= 4) {
     InterpolateRow = InterpolateRow_Any_SSE2;
@@ -344,10 +350,11 @@ static void ScaleARGBBilinearUp(int src_width, int src_height,
 #endif
   }
 
-  const int max_y = (src_height - 1) << 16;
   if (y > max_y) {
     y = max_y;
   }
+
+  {
     int yi = y >> 16;
     const uint8* src = src_argb + yi * src_stride;
 
@@ -392,6 +399,7 @@ static void ScaleARGBBilinearUp(int src_width, int src_height,
       y += dy;
     }
     free_aligned_buffer_64(row);
+  }
 }
 
 #ifdef YUVSCALEUP