Save and restore last 16 bytes of filtered rows when used for ARGBInterpolate.

BUG=50
TEST=none
Review URL: https://webrtc-codereview.appspot.com/673012

git-svn-id: http://libyuv.googlecode.com/svn/trunk@303 16f28f9a-4ce2-e073-06de-1de4eb20be90

README.chromium

 Name: libyuv
 URL: http://code.google.com/p/libyuv/
-Version: 302
+Version: 303
 License: BSD
 License File: LICENSE
 

include/libyuv/planar_functions.h

@@ -217,6 +217,7 @@ int ARGBShade(const uint8* src_argb, int src_stride_argb,
 // 'interpolation' is specified as 8 bit fraction where 0 means 100% src_argb0
 // and 255 means 1% src_argb0 and 99% src_argb1.
 // Internally uses ARGBScale bilinear filtering.
+// Caveat: This function will write up to 16 bytes beyond the end of dst_argb.
 int ARGBInterpolate(const uint8* src_argb0, int src_stride_argb0,
                     const uint8* src_argb1, int src_stride_argb1,
                     uint8* dst_argb, int dst_stride_argb,

include/libyuv/version.h

@@ -11,6 +11,6 @@
 #ifndef INCLUDE_LIBYUV_VERSION_H_  // NOLINT
 #define INCLUDE_LIBYUV_VERSION_H_
 
-#define LIBYUV_VERSION 302
+#define LIBYUV_VERSION 303
 
 #endif  // INCLUDE_LIBYUV_VERSION_H_  NOLINT

source/planar_functions.cc

@@ -1147,9 +1147,13 @@ int ARGBInterpolate(const uint8* src_argb0, int src_stride_argb0,
     ScaleARGBFilterRows = ScaleARGBFilterRows_SSSE3;
   }
 #endif
+  uint8 last16[16];
   for (int y = 0; y < height; ++y) {
+    // Filter extrudes edge for its scaling purpose.
+    memcpy(last16, dst_argb + width * 4, 16);  // Save last 16 beyond end.
     ScaleARGBFilterRows(dst_argb, src_argb0, src_argb1 - src_argb0,
                         width, interpolation);
+    memcpy(dst_argb + width * 4, last16, 16);  // Restore last 16 beyond end.
     src_argb0 += src_stride_argb0;
     src_argb1 += src_stride_argb1;
     dst_argb += dst_stride_argb;