add more color formats NV21 and YV12 in video capture (mainly from Android).

media/base/yuv_convert.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.
 
 // This webpage shows layout of YV12 and other YUV formats
 // http://www.fourcc.org/yuv.php
 // The actual conversion is best described here
 // http://en.wikipedia.org/wiki/YUV
 // An article on optimizing YUV conversion using tables instead of multiplies
 // http://lestourtereaux.free.fr/papers/data/yuvrgb.pdf
@@ skipping 490 matching lines @@
     }
     for (int j = 0; j < (width / 2); ++j) {
       yplane[0] = src[0];
       yplane[1] = src[2];
       src += 4;
       yplane += 2;
     }
   }
 }
 
+void ConvertNV21ToYUV(const uint8* src,
+                      uint8* yplane,
+                      uint8* uplane,
+                      uint8* vplane,
+                      int width,
+                      int height) {
+  int y_plane_size = width * height;
+  memcpy(yplane, src, y_plane_size);
+
+  src += y_plane_size;
+  int u_plane_size = y_plane_size >> 2;
+  for (int i = 0; i < u_plane_size; ++i) {
+    *vplane++ = *src++;
+    *uplane++ = *src++;
+  }
+}
+
 void ConvertYUVToRGB32(const uint8* yplane,
                        const uint8* uplane,
                        const uint8* vplane,
                        uint8* rgbframe,
                        int width,
                        int height,
                        int ystride,
                        int uvstride,
                        int rgbstride,
                        YUVType yuv_type) {
@@ skipping 10 matching lines @@
     else
       convert_proc = &ConvertYUVToRGB32_C;
   }
 
   convert_proc(yplane, uplane, vplane, rgbframe,
                width, height, ystride, uvstride, rgbstride, yuv_type);
 #endif
 }
 
 }  // namespace media