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zopflib/src/zopflipng/lodepng/lodepng.h  view on Meta::CPAN

    cleaned out code as well as making certain parts faster.
*) 28 dec 2006: Added "Settings" to the encoder.
*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now.
    Removed some code duplication in the decoder. Fixed little bug in an example.
*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter.
    Fixed a bug of the decoder with 16-bit per color.
*) 15 okt 2006: Changed documentation structure
*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the
    given image buffer, however for now it's not compressed.
*) 08 sep 2006: (!) Changed to interface with a Decoder class
*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different
    way. Renamed decodePNG to decodePNGGeneric.
*) 29 jul 2006: (!) Changed the interface: image info is now returned as a
    struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy.
*) 28 jul 2006: Cleaned the code and added new error checks.
    Corrected terminology "deflate" into "inflate".
*) 23 jun 2006: Added SDL example in the documentation in the header, this
    example allows easy debugging by displaying the PNG and its transparency.
*) 22 jun 2006: (!) Changed way to obtain error value. Added
    loadFile function for convenience. Made decodePNG32 faster.
*) 21 jun 2006: (!) Changed type of info vector to unsigned.

zopflib/src/zopflipng/lodepng/lodepng_util.cpp  view on Meta::CPAN

struct ExtractPNG //PNG decoding and information extraction
{
  std::vector<ZlibBlockInfo>* zlibinfo;
  ExtractPNG(std::vector<ZlibBlockInfo>* info) : zlibinfo(info) {};
  int error;
  void decode(const unsigned char* in, size_t size)
  {
    error = 0;
    if(size == 0 || in == 0) { error = 48; return; } //the given data is empty
    readPngHeader(&in[0], size); if(error) return;
    size_t pos = 33; //first byte of the first chunk after the header
    std::vector<unsigned char> idat; //the data from idat chunks
    bool IEND = false;
    //loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
    //IDAT data is put at the start of the in buffer
    while(!IEND)
    {
      //error: size of the in buffer too small to contain next chunk
      if(pos + 8 >= size) { error = 30; return; }
      size_t chunkLength = read32bitInt(&in[pos]); pos += 4;

zopflib/src/zopflipng/lodepng/lodepng_util.cpp  view on Meta::CPAN

      }
      pos += 4; //step over CRC (which is ignored)
    }
    std::vector<unsigned char> out; //now the out buffer will be filled
    ExtractZlib zlib(zlibinfo); //decompress with the Zlib decompressor
    error = zlib.decompress(out, idat);
    if(error) return; //stop if the zlib decompressor returned an error
  }

  //read the information from the header and store it in the Info
  void readPngHeader(const unsigned char* in, size_t inlength)
  {
    if(inlength < 29) { error = 27; return; } //error: the data length is smaller than the length of the header
    if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
    || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) { error = 28; return; } //no PNG signature
    //error: it doesn't start with a IHDR chunk!
    if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R') { error = 29; return; }
  }

  unsigned long readBitFromReversedStream(size_t& bitp, const unsigned char* bits)
  {