streamtools/rescalers/xdrop9.cpp

   1 #include "rescalers/simple.hpp"
   2 #include <stdint.h>
   3 #include <cmath>
   4 #include <stdexcept>
   5
   6 namespace
   7 {
   8         void do_rescale(uint8_t* target, uint32_t twidth, uint32_t theight,
   9                 const uint8_t* source, uint32_t swidth, uint32_t sheight)
  10         {
  11                 uint32_t* __restrict__ src = (uint32_t*)source;
  12                 uint32_t* __restrict__ dest = (uint32_t*)target;
  13
  14                 if(theight != sheight || twidth % 8 || swidth % 9 || swidth / 9 * 8 != twidth)
  15                         throw std::runtime_error("xdrop9: Incorrect scale factor");
  16
  17                 for(uint32_t y = 0; y < theight; y++)
  18                         for(uint32_t x = 0; x < twidth; x++) {
  19                                 uint32_t _x = x / 8 * 9 + x % 8;
  20                                 dest[y * twidth + x] = src[y * swidth + _x];
  21                         }
  22         }
  23
  24         simple_rescaler factory("xdrop9", make_bound_method(do_rescale));
  25 }