streamtools/rescalers/xdrop9.cpp

   1 #include "rescalers/simple.hpp"
   2 #include <stdint.h>
   3 #include <sstream>
   4 #include <cmath>
   5 #include <stdexcept>
   6
   7 namespace
   8 {
   9         void do_rescale(uint8_t* target, uint32_t twidth, uint32_t theight,
  10                 const uint8_t* source, uint32_t swidth, uint32_t sheight)
  11         {
  12                 uint32_t* __restrict__ src = (uint32_t*)source;
  13                 uint32_t* __restrict__ dest = (uint32_t*)target;
  14
  15                 if(twidth % 8)
  16                         throw std::runtime_error("Expected target width to be divisible by 8");
  17                 if(theight != sheight || swidth / 9 * 8 != twidth) {
  18                         std::ostringstream str;
  19                         str << "xdrop9: Expected source to have resolution of " << twidth / 8 * 9 << "x"
  20                                 << theight << ", got " << swidth << "x" << sheight << ".";
  21                         throw std::runtime_error(str.str());
  22                 }
  23
  24                 for(uint32_t y = 0; y < theight; y++)
  25                         for(uint32_t x = 0; x < twidth; x++) {
  26                                 uint32_t _x = x / 8 * 9 + x % 8;
  27                                 dest[y * twidth + x] = src[y * swidth + _x];
  28                         }
  29         }
  30
  31         simple_rescaler factory("xdrop9", make_bound_method(do_rescale));
  32 }