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common/rfb/Encoder.h

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+/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
+ * Copyright (C) 2011 D. R. Commander.  All Rights Reserved.
+ * Copyright 2014 Pierre Ossman for Cendio AB
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+#ifndef __RFB_ENCODER_H__
+#define __RFB_ENCODER_H__
+
+#include <rdr/types.h>
+#include <rfb/Rect.h>
+
+namespace rfb {
+  class SConnection;
+  class PixelBuffer;
+  class Palette;
+  class PixelFormat;
+
+  enum EncoderFlags {
+    // A constant for encoders that don't need anything special
+    EncoderPlain = 0,
+    // Give us the raw frame buffer, and not something converted to
+    // the what the client is asking for.
+    EncoderUseNativePF = 1 << 0,
+    // Encoder does not encode pixels perfectly accurate
+    EncoderLossy = 1 << 1,
+  };
+
+  class Encoder {
+  public:
+    Encoder(SConnection* conn, int encoding,
+            enum EncoderFlags flags, unsigned int maxPaletteSize);
+    virtual ~Encoder();
+
+    // isSupported() should return a boolean indicating if this encoder
+    // is okay to use with the current connection. This usually involves
+    // checking the list of encodings in the connection parameters.
+    virtual bool isSupported()=0;
+
+    virtual void setCompressLevel(int level) {};
+    virtual void setQualityLevel(int level) {};
+    virtual void setFineQualityLevel(int quality, int subsampling) {};
+
+    virtual bool treatLossless() { return !(flags & EncoderLossy); }
+
+    // writeRect() is the main interface that encodes the given rectangle
+    // with data from the PixelBuffer onto the SConnection given at
+    // encoder creation.
+    //
+    // The PixelBuffer will be in the PixelFormat specified in ConnParams
+    // unless the flag UseNativePF is specified. In that case the
+    // PixelBuffer will remain in its native format and encoder will have
+    // to handle any conversion itself.
+    //
+    // The Palette will always be in the PixelFormat specified in
+    // ConnParams. An empty palette indicates a large number of colours,
+    // but could still be less than maxPaletteSize.
+    virtual void writeRect(const PixelBuffer* pb, const Palette& palette)=0;
+
+    // writeSolidRect() is a short cut in order to encode single colour
+    // rectangles efficiently without having to create a fake single
+    // colour PixelBuffer. The colour argument follows the same semantics
+    // as the PixelBuffer for writeRect().
+    //
+    // Note that there is a default implementation that can be called
+    // using Encoder::writeSolidRect() in the event that there is no
+    // efficient short cut.
+    virtual void writeSolidRect(int width, int height,
+                                const PixelFormat& pf,
+                                const rdr::U8* colour)=0;
+
+  protected:
+    // Helper method for redirecting a single colour palette to the
+    // short cut method.
+    void writeSolidRect(const PixelBuffer* pb, const Palette& palette);
+
+  public:
+    const int encoding;
+    const enum EncoderFlags flags;
+
+    // Maximum size of the palette per rect
+    const unsigned int maxPaletteSize;
+
+  protected:
+    SConnection* conn;
+  };
+}
+
+#endif