text: /* The copyright in this software is being made available under the BSD
   * License, included below. This software may be subject to other third party
   * and contributor rights, including patent rights, and no such rights are
   * granted under this license.
   *
   * Copyright (c) 2010-2016, ITU/ISO/IEC
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   *  * Redistributions of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   *  * Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
   *    be used to endorse or promote products derived from this software without
   *    specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
   * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   * THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "TComPicYuv.h"
  #include "libmd5/MD5.h"
  
  //! \ingroup TLibCommon
  //! \{
  
  /**
   * Update md5 using n samples from plane, each sample is adjusted to
   * OUTBIT_BITDEPTH_DIV8.
   */
  template<UInt OUTPUT_BITDEPTH_DIV8>
  static Void md5_block(MD5& md5, const Pel* plane, UInt n)
  {
    /* create a 64 byte buffer for packing Pel's into */
    UChar buf[64/OUTPUT_BITDEPTH_DIV8][OUTPUT_BITDEPTH_DIV8];
    for (UInt i = 0; i < n; i++)
    {
      Pel pel = plane[i];
      /* perform bitdepth and endian conversion */
      for (UInt d = 0; d < OUTPUT_BITDEPTH_DIV8; d++)
      {
        buf[i][d] = pel >> (d*8);
      }
    }
    md5.update((UChar*)buf, n * OUTPUT_BITDEPTH_DIV8);
  }
  
  /**
   * Update md5 with all samples in plane in raster order, each sample
   * is adjusted to OUTBIT_BITDEPTH_DIV8.
   */
  template<UInt OUTPUT_BITDEPTH_DIV8>
  static Void md5_plane(MD5& md5, const Pel* plane, UInt width, UInt height, UInt stride)
  {
    /* N is the number of samples to process per md5 update.
     * All N samples must fit in buf */
    UInt N = 32;
    UInt width_modN = width % N;
    UInt width_less_modN = width - width_modN;
  
    for (UInt y = 0; y < height; y++)
    {
      /* convert pels into unsigned chars in little endian byte order.
       * NB, for 8bit data, data is truncated to 8bits. */
      for (UInt x = 0; x < width_less_modN; x += N)
      {
        md5_block<OUTPUT_BITDEPTH_DIV8>(md5, &plane[y*stride + x], N);
      }
  
      /* mop up any of the remaining line */
      md5_block<OUTPUT_BITDEPTH_DIV8>(md5, &plane[y*stride + width_less_modN], width_modN);
    }
  }
  
  
  UInt compCRC(Int bitdepth, const Pel* plane, UInt width, UInt height, UInt stride, TComPictureHash &digest)
  {
    UInt crcMsb;
    UInt bitVal;
    UInt crcVal = 0xffff;
    UInt bitIdx;
    for (UInt y = 0; y < height; y++)
    {
      for (UInt x = 0; x < width; x++)
      {
        // take CRC of first pictureData byte
        for(bitIdx=0; bitIdx<8; bitIdx++)
        {
          crcMsb = (crcVal >> 15) & 1;
          bitVal = (plane[y*stride+x] >> (7 - bitIdx)) & 1;
          crcVal = (((crcVal << 1) + bitVal) & 0xffff) ^ (crcMsb * 0x1021);
        }
        // take CRC of second pictureData byte if bit depth is greater than 8-bits
        if(bitdepth > 8)
        {
          for(bitIdx=0; bitIdx<8; bitIdx++)
          {
            crcMsb = (crcVal >> 15) & 1;
            bitVal = (plane[y*stride+x] >> (15 - bitIdx)) & 1;
            crcVal = (((crcVal << 1) + bitVal) & 0xffff) ^ (crcMsb * 0x1021);
          }
        }
      }
    }
    for(bitIdx=0; bitIdx<16; bitIdx++)
    {
      crcMsb = (crcVal >> 15) & 1;
      crcVal = ((crcVal << 1) & 0xffff) ^ (crcMsb * 0x1021);
    }
  
    digest.hash.push_back((crcVal>>8)  & 0xff);
    digest.hash.push_back( crcVal      & 0xff);
    return 2;
  }
  
  UInt calcCRC(const TComPicYuv& pic, TComPictureHash &digest, const BitDepths &bitDepths)
  {
    UInt digestLen=0;
    digest.hash.clear();
    for(Int chan=0; chan<pic.getNumberValidComponents(); chan++)
    {
      const ComponentID compID=ComponentID(chan);
      digestLen=compCRC(bitDepths.recon[toChannelType(compID)], pic.getAddr(compID), pic.getWidth(compID), pic.getHeight(compID), pic.getStride(compID), digest);
    }
    return digestLen;
  }
  
  UInt compChecksum(Int bitdepth, const Pel* plane, UInt width, UInt height, UInt stride, TComPictureHash &digest, const BitDepths &/*bitDepths*/)
  {
    UInt checksum = 0;
    UChar xor_mask;
  
    for (UInt y = 0; y < height; y++)
    {
      for (UInt x = 0; x < width; x++)
      {
        xor_mask = (x & 0xff) ^ (y & 0xff) ^ (x >> 8) ^ (y >> 8);
        checksum = (checksum + ((plane[y*stride+x] & 0xff) ^ xor_mask)) & 0xffffffff;
  
        if(bitdepth > 8)
        {
          checksum = (checksum + ((plane[y*stride+x]>>8) ^ xor_mask)) & 0xffffffff;
        }
      }
    }
  
    digest.hash.push_back((checksum>>24) & 0xff);
    digest.hash.push_back((checksum>>16) & 0xff);
    digest.hash.push_back((checksum>>8)  & 0xff);
    digest.hash.push_back( checksum      & 0xff);
    return 4;
  }
  
  UInt calcChecksum(const TComPicYuv& pic, TComPictureHash &digest, const BitDepths &bitDepths)
  {
    UInt digestLen=0;
    digest.hash.clear();
    for(Int chan=0; chan<pic.getNumberValidComponents(); chan++)
    {
      const ComponentID compID=ComponentID(chan);
      digestLen=compChecksum(bitDepths.recon[toChannelType(compID)], pic.getAddr(compID), pic.getWidth(compID), pic.getHeight(compID), pic.getStride(compID), digest, bitDepths);
    }
    return digestLen;
  }
  /**
   * Calculate the MD5sum of pic, storing the result in digest.
   * MD5 calculation is performed on Y' then Cb, then Cr; each in raster order.
   * Pel data is inserted into the MD5 function in little-endian byte order,
   * using sufficient bytes to represent the picture bitdepth.  Eg, 10bit data
   * uses little-endian two byte words; 8bit data uses single byte words.
   */
  UInt calcMD5(const TComPicYuv& pic, TComPictureHash &digest, const BitDepths &bitDepths)
  {
    /* choose an md5_plane packing function based on the system bitdepth */
    typedef Void (*MD5PlaneFunc)(MD5&, const Pel*, UInt, UInt, UInt);
    MD5PlaneFunc md5_plane_func;
  
    MD5 md5[MAX_NUM_COMPONENT];
  
    digest.hash.clear();
    for(Int chan=0; chan<pic.getNumberValidComponents(); chan++)
    {
      const ComponentID compID=ComponentID(chan);
      md5_plane_func = bitDepths.recon[toChannelType(compID)] <= 8 ? (MD5PlaneFunc)md5_plane<1> : (MD5PlaneFunc)md5_plane<2>;
      UChar tmp_digest[MD5_DIGEST_STRING_LENGTH];
      md5_plane_func(md5[compID], pic.getAddr(compID), pic.getWidth(compID), pic.getHeight(compID), pic.getStride(compID));
      md5[compID].finalize(tmp_digest);
      for(UInt i=0; i<MD5_DIGEST_STRING_LENGTH; i++)
      {
        digest.hash.push_back(tmp_digest[i]);
      }
    }
    return 16;
  }
  
  std::string hashToString(const TComPictureHash &digest, Int numChar)
  {
    static const TChar* hex = "0123456789abcdef";
    std::string result;
  
    for(Int pos=0; pos<Int(digest.hash.size()); pos++)
    {
      if ((pos % numChar) == 0 && pos!=0 )
      {
        result += ',';
      }
      result += hex[digest.hash[pos] >> 4];
      result += hex[digest.hash[pos] & 0xf];
    }
  
    return result;
  }
  
  //! \}
  