Function DecompressZip

SampleFramework12/v1.00/TinyEXR.cpp:6929–6974

}

void DecompressZip(unsigned char *dst, unsigned long &uncompressedSize,
                   const unsigned char *src, unsigned long srcSize) {
  std::vector<unsigned char> tmpBuf(uncompressedSize);

  int ret =
      miniz::mz_uncompress(&tmpBuf.at(0), &uncompressedSize, src, srcSize);
  assert(ret == miniz::MZ_OK);

  //
  // Apply EXR-specific? postprocess. Grabbed from OpenEXR's
  // ImfZipCompressor.cpp
  //

  // Predictor.
  {
    unsigned char *t = &tmpBuf.at(0) + 1;
    unsigned char *stop = &tmpBuf.at(0) + uncompressedSize;

    while (t < stop) {
      int d = int(t[-1]) + int(t[0]) - 128;
      t[0] = d;
      ++t;
    }
  }

  // Reorder the pixel data.
  {
    const char *t1 = reinterpret_cast<const char *>(&tmpBuf.at(0));
    const char *t2 = reinterpret_cast<const char *>(&tmpBuf.at(0)) +
                     (uncompressedSize + 1) / 2;
    char *s = reinterpret_cast<char *>(dst);
    char *stop = s + uncompressedSize;

    while (true) {
      if (s < stop)
        *(s++) = *(t1++);
      else
        break;

      if (s < stop)
        *(s++) = *(t2++);
      else
        break;
    }
  }
}

} // namespace