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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this file,

  * You can obtain one at http://mozilla.org/MPL/2.0/. */

 #ifndef YUV_STAMPER_H_

 #define YUV_STAMPER_H_

 #include "nptypes.h"

 namespace mozilla {

 class

 YuvStamper {

 public:

   bool WriteDigits(uint32_t value);

   template<typename T>

   static bool Write(uint32_t width, uint32_t height, uint32_t stride,

                     unsigned char *pYData, const T& value,

                     uint32_t x=0, uint32_t y=0)

   {

     YuvStamper stamper(pYData, width, height, stride,

 		       x, y,

 		       (sDigitWidth + sInterDigit) * sPixelSize,

 		       (sDigitHeight + sInterLine) * sPixelSize);

     return stamper.WriteDigits(value);

   }

   static bool Encode(uint32_t width, uint32_t height, uint32_t stride,

 		     unsigned char* pYData, unsigned char* pMsg, size_t msg_len,

 		     uint32_t x = 0, uint32_t y = 0);

   static bool Decode(uint32_t width, uint32_t height, uint32_t stride,

 		     unsigned char* pYData, unsigned char* pMsg, size_t msg_len,

 		     uint32_t x = 0, uint32_t y = 0);

  private:

   YuvStamper(unsigned char* pYData,

 	     uint32_t width, uint32_t height, uint32_t stride,

 	     uint32_t x, uint32_t y,

 	     unsigned char symbol_width, unsigned char symbol_height);

   bool WriteDigit(unsigned char digit);

   void WritePixel(unsigned char* data, uint32_t x, uint32_t y);

   uint32_t Capacity();

   bool AdvanceCursor();

   bool WriteBit(bool one);

   bool Write8(unsigned char value);

   bool ReadBit(unsigned char &value);

   bool Read8(unsigned char &bit);

   const static unsigned char sPixelSize = 3;

   const static unsigned char sDigitWidth = 6;

   const static unsigned char sDigitHeight = 7;

   const static unsigned char sInterDigit = 1;

   const static unsigned char sInterLine = 1;

   const static uint32_t sBitSize = 4;

   const static uint32_t sBitThreshold = 60;

   const static unsigned char sYOn = 0x80;

   const static unsigned char sYOff = 0;

   const static unsigned char sLumaThreshold = 96;

   const static unsigned char sLumaMin = 16;

   const static unsigned char sLumaMax = 235;

   unsigned char* pYData;

   uint32_t mStride;

   uint32_t mWidth;

   uint32_t mHeight;

   unsigned char mSymbolWidth;

   unsigned char mSymbolHeight;

   struct Cursor {

     Cursor(uint32_t x, uint32_t y):

       x(x), y(y) {}

     uint32_t x;

     uint32_t y;

   } mCursor;

 };

 }

 #endif