ScaleYV12 optimization....

media/base/yuv_convert.h

 // Copyright (c) 2009 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.
 
 #ifndef MEDIA_BASE_YUV_CONVERT_H_
 #define MEDIA_BASE_YUV_CONVERT_H_
 
 #include "base/basictypes.h"
 
 namespace media {
 
-// Convert a frame of YV12 (aka YUV420) to 32 bit ARGB.
-void ConvertYV12ToRGB32(const uint8* yplane,
-                        const uint8* uplane,
-                        const uint8* vplane,
-                        uint8* rgbframe,
-                        size_t frame_width,
-                        size_t frame_height,
-                        int ystride,
-                        int uvstride,
-                        int rgbstride);
+// Type of YUV surface.
+// The value of these enums matter as they are used to shift vertical indices.
+enum YUVType {
+  YV16 = 0,           // YV16 is half width and full height chroma channels.
+  YV12 = 1,           // YV12 is half width and half height chroma channels.
+};
 
-// Convert a frame of YV16 (aka YUV422) to 32 bit ARGB.
-void ConvertYV16ToRGB32(const uint8* yplane,
-                        const uint8* uplane,
-                        const uint8* vplane,
-                        uint8* rgbframe,
-                        size_t frame_width,
-                        size_t frame_height,
-                        int ystride,
-                        int uvstride,
-                        int rgbstride);
+// Mirror means flip the image horizontally, as in looking in a mirror.
+// Rotate happens after mirroring.
+enum Rotate {
+  ROTATE_0,           // Rotation off.
+  ROTATE_90,          // Rotate clockwise.
+  ROTATE_180,         // Rotate upside down.
+  ROTATE_270,         // Rotate counter clockwise.
+  MIRROR_ROTATE_0,    // Mirror horizontally.
+  MIRROR_ROTATE_90,   // Mirror then Rotate clockwise.
+  MIRROR_ROTATE_180,  // Mirror vertically.
+  MIRROR_ROTATE_270,  // Transpose.
+};
 
+// Convert a frame of YUV to 32 bit ARGB.
+// Pass in YV16/YV12 depending on source format
+void ConvertYUVToRGB32(const uint8* yplane,
+                       const uint8* uplane,
+                       const uint8* vplane,
+                       uint8* rgbframe,
+                       int frame_width,
+                       int frame_height,
+                       int ystride,
+                       int uvstride,
+                       int rgbstride,
+                       YUVType yuv_type);
+
+// Scale a frame of YUV to 32 bit ARGB.
+// Supports rotation and mirroring.
+void ScaleYUVToRGB32(const uint8* yplane,
+                     const uint8* uplane,
+                     const uint8* vplane,
+                     uint8* rgbframe,
+                     int frame_width,
+                     int frame_height,
+                     int scaled_width,
+                     int scaled_height,
+                     int ystride,
+                     int uvstride,
+                     int rgbstride,
+                     YUVType yuv_type,
+                     Rotate view_rotate);
+
+}  // namespace media
 
 #endif  // MEDIA_BASE_YUV_CONVERT_H_
-
-}  // namespace media