Fix the WebRTC color bug.

media/base/simd/convert_yuv_to_rgb_c.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/base/simd/convert_yuv_to_rgb.h"
 #include "media/base/simd/yuv_to_rgb_table.h"
 
 namespace media {
 
 #define packuswb(x) ((x) < 0 ? 0 : ((x) > 255 ? 255 : (x)))
 #define paddsw(x, y) (((x) + (y)) < -32768 ? -32768 : \
     (((x) + (y)) > 32767 ? 32767 : ((x) + (y))))
 
+// On Android, pixel layout is RGBA
+// (see third_party/skia/include/core/SkColorPriv.h);
+// however, other Chrome platforms use BGRA
+// (see skia/config/SkUserConfig.h).
+// Ideally, android should not use the function here
+// due to performance issue(crbug/249980).

[scherkus (not reviewing), 2013/06/15 00:31:56]

nit: can you better format this comment?

for example ... try to use the full 80 character limit we have

links should also be full urls and clickable

e.g., http://crbug.com/249980

[hkuang1, 2013/06/15 00:54:01]

Done.

+#if defined(OS_ANDROID)
+#define SK_R32_SHIFT    0
+#define SK_G32_SHIFT    8
+#define SK_B32_SHIFT    16
+#define SK_A32_SHIFT    24
+#else
+#define SK_B32_SHIFT    0
+#define SK_G32_SHIFT    8
+#define SK_R32_SHIFT    16
+#define SK_A32_SHIFT    24
+#endif
+
 static inline void ConvertYUVToRGB32_C(uint8 y,
                                        uint8 u,
                                        uint8 v,
                                        uint8* rgb_buf) {
   int b = kCoefficientsRgbY[256+u][0];
   int g = kCoefficientsRgbY[256+u][1];
   int r = kCoefficientsRgbY[256+u][2];
   int a = kCoefficientsRgbY[256+u][3];
 
   b = paddsw(b, kCoefficientsRgbY[512+v][0]);
   g = paddsw(g, kCoefficientsRgbY[512+v][1]);
   r = paddsw(r, kCoefficientsRgbY[512+v][2]);
   a = paddsw(a, kCoefficientsRgbY[512+v][3]);
 
   b = paddsw(b, kCoefficientsRgbY[y][0]);
   g = paddsw(g, kCoefficientsRgbY[y][1]);
   r = paddsw(r, kCoefficientsRgbY[y][2]);
   a = paddsw(a, kCoefficientsRgbY[y][3]);
 
   b >>= 6;
   g >>= 6;
   r >>= 6;
   a >>= 6;
 
-  *reinterpret_cast<uint32*>(rgb_buf) = (packuswb(b)) |
-                                        (packuswb(g) << 8) |
-                                        (packuswb(r) << 16) |
-                                        (packuswb(a) << 24);
+  *reinterpret_cast<uint32*>(rgb_buf) = (packuswb(b) << SK_B32_SHIFT) |
+                                        (packuswb(g) << SK_G32_SHIFT) |
+                                        (packuswb(r) << SK_R32_SHIFT) |
+                                        (packuswb(a) << SK_A32_SHIFT);
 }
 
 static inline void ConvertYUVAToARGB_C(uint8 y,
                                        uint8 u,
                                        uint8 v,
                                        uint8 a,
                                        uint8* rgb_buf) {
   int b = kCoefficientsRgbY[256+u][0];
   int g = kCoefficientsRgbY[256+u][1];
   int r = kCoefficientsRgbY[256+u][2];
 
   b = paddsw(b, kCoefficientsRgbY[512+v][0]);
   g = paddsw(g, kCoefficientsRgbY[512+v][1]);
   r = paddsw(r, kCoefficientsRgbY[512+v][2]);
 
   b = paddsw(b, kCoefficientsRgbY[y][0]);
   g = paddsw(g, kCoefficientsRgbY[y][1]);
   r = paddsw(r, kCoefficientsRgbY[y][2]);
 
   b >>= 6;
   g >>= 6;
   r >>= 6;
 
   b = packuswb(b) * a >> 8;
   g = packuswb(g) * a >> 8;
   r = packuswb(r) * a >> 8;
 
-  *reinterpret_cast<uint32*>(rgb_buf) = b | (g << 8) | (r << 16) | (a << 24);
+  *reinterpret_cast<uint32*>(rgb_buf) = (b << SK_B32_SHIFT) |
+                                        (g << SK_G32_SHIFT) |
+                                        (r << SK_R32_SHIFT) |
+                                        (a << SK_A32_SHIFT);
 }
 
 void ConvertYUVToRGB32Row_C(const uint8* y_buf,
                             const uint8* u_buf,
                             const uint8* v_buf,
                             uint8* rgb_buf,
                             ptrdiff_t width) {
   for (int x = 0; x < width; x += 2) {
     uint8 u = u_buf[x >> 1];
     uint8 v = v_buf[x >> 1];
@@ skipping 149 matching lines @@
     ConvertYUVAToARGBRow_C(y_ptr,
                            u_ptr,
                            v_ptr,
                            a_ptr,
                            rgba_row,
                            width);
   }
 }
 
 }  // namespace media