git.sesse.net Git - movit/blob - ycbcr_conversion_effect.cpp

   1 #include <epoxy/gl.h>
   2 #include <assert.h>
   3 #include <stdio.h>
   4 #include <algorithm>
   5 #include <Eigen/Core>
   6 #include <Eigen/LU>
   7
   8 #include "ycbcr_conversion_effect.h"
   9 #include "effect_util.h"
  10 #include "util.h"
  11 #include "ycbcr.h"
  12
  13 using namespace std;
  14 using namespace Eigen;
  15
  16 namespace movit {
  17
  18 YCbCrConversionEffect::YCbCrConversionEffect(const YCbCrFormat &ycbcr_format)
  19         : ycbcr_format(ycbcr_format)
  20 {
  21         register_uniform_mat3("ycbcr_matrix", &uniform_ycbcr_matrix);
  22         register_uniform_vec3("offset", uniform_offset);
  23         register_uniform_bool("clamp_range", &uniform_clamp_range);
  24
  25         // Only used when clamp_range is true.
  26         register_uniform_vec3("ycbcr_min", uniform_ycbcr_min);
  27         register_uniform_vec3("ycbcr_max", uniform_ycbcr_max);
  28 }
  29
  30 string YCbCrConversionEffect::output_fragment_shader()
  31 {
  32         return read_file("ycbcr_conversion_effect.frag");
  33 }
  34
  35 void YCbCrConversionEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
  36 {
  37         Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
  38
  39         Matrix3d ycbcr_to_rgb;
  40         compute_ycbcr_matrix(ycbcr_format, uniform_offset, &ycbcr_to_rgb);
  41
  42         uniform_ycbcr_matrix = ycbcr_to_rgb.inverse();
  43
  44         if (ycbcr_format.full_range) {
  45                 // The card will clamp for us later.
  46                 uniform_clamp_range = false;
  47         } else {
  48                 uniform_clamp_range = true;
  49
  50                 if (ycbcr_format.num_levels == 256) {  // 8-bit.
  51                         // These limits come from BT.601 page 8, or BT.709, page 5.
  52                         uniform_ycbcr_min[0] = 16.0 / 255.0;
  53                         uniform_ycbcr_min[1] = 16.0 / 255.0;
  54                         uniform_ycbcr_min[2] = 16.0 / 255.0;
  55                         uniform_ycbcr_max[0] = 235.0 / 255.0;
  56                         uniform_ycbcr_max[1] = 240.0 / 255.0;
  57                         uniform_ycbcr_max[2] = 240.0 / 255.0;
  58                 } else if (ycbcr_format.num_levels == 1024) {  // 10-bit.
  59                         // BT.709, page 5, or BT.2020, page 6.
  60                         uniform_ycbcr_min[0] = 64.0 / 1023.0;
  61                         uniform_ycbcr_min[1] = 64.0 / 1023.0;
  62                         uniform_ycbcr_min[2] = 64.0 / 1023.0;
  63                         uniform_ycbcr_max[0] = 940.0 / 1023.0;
  64                         uniform_ycbcr_max[1] = 960.0 / 1023.0;
  65                         uniform_ycbcr_max[2] = 960.0 / 1023.0;
  66                 } else if (ycbcr_format.num_levels == 4096) {  // 12-bit.
  67                         // BT.2020, page 6.
  68                         uniform_ycbcr_min[0] = 256.0 / 4095.0;
  69                         uniform_ycbcr_min[1] = 256.0 / 4095.0;
  70                         uniform_ycbcr_min[2] = 256.0 / 4095.0;
  71                         uniform_ycbcr_max[0] = 3760.0 / 4095.0;
  72                         uniform_ycbcr_max[1] = 3840.0 / 4095.0;
  73                         uniform_ycbcr_max[2] = 3840.0 / 4095.0;
  74                 } else {
  75                         assert(false);
  76                 }
  77         }
  78 }
  79
  80 }  // namespace movit