Introducing a helper wrapper for YUV-to-RGB convertion and/or scaling.

remoting/base/decoder_vp8.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 "remoting/base/decoder_vp8.h"
 
 #include <math.h>
 
 #include "base/logging.h"
 #include "media/base/media.h"
@@ skipping 124 matching lines @@
   // TODO(wez): Fix the rest of the decode pipeline not to assume the frame
   // size is the host dimensions, since it's not when scaling.  If the host
   // gets smaller, then the output size will be too big and we'll overrun the
   // frame, so currently we render 1:1 in that case; the app will see the
   // host size change and resize us if need be.
   if (output_size_.width() > static_cast<int>(frame_->width()))
     output_size_.set(frame_->width(), output_size_.height());
   if (output_size_.height() > static_cast<int>(frame_->height()))
     output_size_.set(output_size_.width(), frame_->height());
 
-  if (!DoScaling()) {
-    ConvertRegion(region, &updated_region_);
-  } else {
-    ScaleAndConvertRegion(region, &updated_region_);
-  }
-}
-
-bool DecoderVp8::DoScaling() const {
-  DCHECK(last_image_);
-  return !output_size_.equals(last_image_->d_w, last_image_->d_h);
-}
-
-void DecoderVp8::ConvertRegion(const SkRegion& input_region,
-                               SkRegion* output_region) {
   if (!last_image_)
     return;
 
-  output_region->setEmpty();
+  updated_region_.setEmpty();
 
   // Clip based on both the output dimensions and Pepper clip rect.
-  // ConvertYUVToRGB32WithRect() requires even X and Y coordinates, so we align
-  // |clip_rect| to prevent clipping from breaking alignment.  We then clamp it
-  // to the image dimensions, which may lead to odd width & height, which we
-  // can cope with.
+  // ConvertAndScaleYUVToRGB32Rect() requires even X and Y coordinates, so we
+  // align |clip_rect| to prevent clipping from breaking alignment.  We then
+  // clamp it to the image dimensions, which may lead to odd width & height,
+  // which we can cope with.
   SkIRect clip_rect = AlignRect(clip_rect_);
-  if (!clip_rect.intersect(SkIRect::MakeWH(last_image_->d_w, last_image_->d_h)))
-    return;
-
-  uint8* output_rgb_buf = frame_->data(media::VideoFrame::kRGBPlane);
-  const int output_stride = frame_->stride(media::VideoFrame::kRGBPlane);
-
-  for (SkRegion::Iterator i(input_region); !i.done(); i.next()) {
-    // Align the rectangle so the top-left coordinates are even, for
-    // ConvertYUVToRGB32WithRect().
-    SkIRect dest_rect(AlignRect(i.rect()));
-
-    // Clip the rectangle, preserving alignment since |clip_rect| is aligned.
-    if (!dest_rect.intersect(clip_rect))
-      continue;
-
-    ConvertYUVToRGB32WithRect(last_image_->planes[0],
-                              last_image_->planes[1],
-                              last_image_->planes[2],
-                              output_rgb_buf,
-                              dest_rect,
-                              last_image_->stride[0],
-                              last_image_->stride[1],
-                              output_stride);
-
-    output_region->op(dest_rect, SkRegion::kUnion_Op);
-  }
-}
-
-void DecoderVp8::ScaleAndConvertRegion(const SkRegion& input_region,
-                                       SkRegion* output_region) {
-  if (!last_image_)
-    return;
-
-  DCHECK(output_size_.width() <= static_cast<int>(frame_->width()));
-  DCHECK(output_size_.height() <= static_cast<int>(frame_->height()));
-
-  output_region->setEmpty();
-
-  // Clip based on both the output dimensions and Pepper clip rect.
-  SkIRect clip_rect = clip_rect_;
   if (!clip_rect.intersect(SkIRect::MakeSize(output_size_)))
     return;
 
   SkISize image_size = SkISize::Make(last_image_->d_w, last_image_->d_h);
   uint8* output_rgb_buf = frame_->data(media::VideoFrame::kRGBPlane);
   const int output_stride = frame_->stride(media::VideoFrame::kRGBPlane);
 
-  for (SkRegion::Iterator i(input_region); !i.done(); i.next()) {
+  for (SkRegion::Iterator i(region); !i.done(); i.next()) {
     // Determine the scaled area affected by this rectangle changing.
-    SkIRect output_rect = ScaleRect(i.rect(), image_size, output_size_);
+    // Align the rectangle so the top-left coordinates are even, for
+    // ConvertAndScaleYUVToRGB32Rect().
+    SkIRect output_rect = ScaleRect(AlignRect(i.rect()),
+                                    image_size, output_size_);
     if (!output_rect.intersect(clip_rect))
       continue;
 
     // The scaler will not to read outside the input dimensions.
-    media::ScaleYUVToRGB32WithRect(last_image_->planes[0],
-                                   last_image_->planes[1],
-                                   last_image_->planes[2],
-                                   output_rgb_buf,
-                                   image_size.width(),
-                                   image_size.height(),
-                                   output_size_.width(),
-                                   output_size_.height(),
-                                   output_rect.x(),
-                                   output_rect.y(),
-                                   output_rect.right(),
-                                   output_rect.bottom(),
-                                   last_image_->stride[0],
-                                   last_image_->stride[1],
-                                   output_stride);
+    ConvertAndScaleYUVToRGB32Rect(last_image_->planes[0],
+                                  last_image_->planes[1],
+                                  last_image_->planes[2],
+                                  last_image_->stride[0],
+                                  last_image_->stride[1],
+                                  image_size,
+                                  SkIRect::MakeSize(image_size),
+                                  output_rgb_buf,
+                                  output_stride,
+                                  output_size_,
+                                  SkIRect::MakeSize(output_size_),
+                                  output_rect);
 
-    output_region->op(output_rect, SkRegion::kUnion_Op);
+    updated_region_.op(output_rect, SkRegion::kUnion_Op);
   }
 }
 
 }  // namespace remoting