Improving the decoder pipeline.

remoting/base/decoder_vp8.h

 // 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.
 
 #ifndef REMOTING_BASE_DECODER_VP8_H_
 #define REMOTING_BASE_DECODER_VP8_H_
 
 #include "remoting/base/decoder.h"
 
 typedef struct vpx_codec_ctx vpx_codec_ctx_t;
 typedef struct vpx_image vpx_image_t;
 
 namespace remoting {
 
 class DecoderVp8 : public Decoder {
  public:
   DecoderVp8();
   virtual ~DecoderVp8();
 
   // Decoder implementations.
-  virtual void Initialize(scoped_refptr<media::VideoFrame> frame) OVERRIDE;
+  virtual void Initialize(const SkISize& screen_size) OVERRIDE;
   virtual DecodeResult DecodePacket(const VideoPacket* packet) OVERRIDE;
-  virtual void GetUpdatedRegion(SkRegion* region) OVERRIDE;
   virtual bool IsReadyForData() OVERRIDE;
   virtual void Reset() OVERRIDE;
   virtual VideoPacketFormat::Encoding Encoding() OVERRIDE;
-  virtual void SetOutputSize(const SkISize& size) OVERRIDE;
-  virtual void SetClipRect(const SkIRect& clip_rect) OVERRIDE;
-  virtual void RefreshRegion(const SkRegion& region) OVERRIDE;
+  virtual void UpdateRegion(const SkRegion& region) OVERRIDE;
+  virtual void Draw(const SkISize& view_size,
+                    const SkIRect& clip_area,
+                    uint8* image_buffer,
+                    int image_stride,
+                    SkRegion* output_region) OVERRIDE;
 
  private:
   enum State {
     kUninitialized,
     kReady,
     kError,
   };
 
-  // Return true if scaling is enabled
-  bool DoScaling() const;
-
-  // Perform color space conversion on the specified region.
-  // Writes the updated region to |output_region|.
-  void ConvertRegion(const SkRegion& region,
-                     SkRegion* output_region);
-
-  // Perform scaling and color space conversion on the specified
-  // region.  Writes the updated rectangles to |output_region|.
-  void ScaleAndConvertRegion(const SkRegion& region,
-                             SkRegion* output_region);
-
   // The internal state of the decoder.
   State state_;
 
-  // The video frame to write to.
-  scoped_refptr<media::VideoFrame> frame_;
-
   vpx_codec_ctx_t* codec_;
 
   // Pointer to the last decoded image.
   vpx_image_t* last_image_;
 
-  // The region updated by the most recent decode.
+  // The region updated that hasn't been copied to the screen yet.
   SkRegion updated_region_;

[Wez, 2012/02/07 01:56:31]

I think this needs renaming, and the semantics clarifying.  This region gets
populated either from an incoming update, or an UpdateRegion call, and cleared
after each Draw().

But what if we Draw only a portion of the desktop, but are keeping a full-sized
framebuffer, i.e. we're just using clipping to optimize out some work?  Then
we've actually lost information on what changed in those other regions.

[alexeypa (please no reviews), 2012/02/15 23:06:22]

Now we validate only the painted area.

 
-  // Clipping rect for the output of the decoder.
-  SkIRect clip_rect_;
-
   // Output dimensions.
-  SkISize output_size_;
+  SkISize screen_size_;
 
   DISALLOW_COPY_AND_ASSIGN(DecoderVp8);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_BASE_DECODER_VP8_H_