]> git.sesse.net Git - movit/blobdiff - ycbcr_input.cpp
Small refactoring in YCbCrInput.
[movit] / ycbcr_input.cpp
index 49747151532ae5863de08fdf0016964cbb2cd30e..ee341f0124de5985da6c2f0d5eb7dcb37ea18a64 100644 (file)
@@ -1,6 +1,6 @@
 #include <Eigen/Core>
 #include <Eigen/LU>
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 #include <assert.h>
 #include <stdio.h>
 #include <string.h>
@@ -58,6 +58,81 @@ float compute_chroma_offset(float pos, unsigned subsampling_factor, unsigned res
        return (0.5 - local_chroma_pos) / resolution;
 }
 
+// Given <ycbcr_format>, compute the values needed to turn Y'CbCr into R'G'B';
+// first subtract the returned offset, then left-multiply the returned matrix
+// (the scaling is already folded into it).
+void compute_ycbcr_matrix(YCbCrFormat ycbcr_format, float* offset, Matrix3d* ycbcr_to_rgb)
+{
+       double coeff[3], scale[3];
+
+       switch (ycbcr_format.luma_coefficients) {
+       case YCBCR_REC_601:
+               // Rec. 601, page 2.
+               coeff[0] = 0.299;
+               coeff[1] = 0.587;
+               coeff[2] = 0.114;
+               break;
+
+       case YCBCR_REC_709:
+               // Rec. 709, page 19.
+               coeff[0] = 0.2126;
+               coeff[1] = 0.7152;
+               coeff[2] = 0.0722;
+               break;
+
+       case YCBCR_REC_2020:
+               // Rec. 2020, page 4.
+               coeff[0] = 0.2627;
+               coeff[1] = 0.6780;
+               coeff[2] = 0.0593;
+               break;
+
+       default:
+               assert(false);
+       }
+
+       if (ycbcr_format.full_range) {
+               offset[0] = 0.0 / 255.0;
+               offset[1] = 128.0 / 255.0;
+               offset[2] = 128.0 / 255.0;
+
+               scale[0] = 1.0;
+               scale[1] = 1.0;
+               scale[2] = 1.0;
+       } else {
+               // Rec. 601, page 4; Rec. 709, page 19; Rec. 2020, page 4.
+               offset[0] = 16.0 / 255.0;
+               offset[1] = 128.0 / 255.0;
+               offset[2] = 128.0 / 255.0;
+
+               scale[0] = 255.0 / 219.0;
+               scale[1] = 255.0 / 224.0;
+               scale[2] = 255.0 / 224.0;
+       }
+
+       // Matrix to convert RGB to YCbCr. See e.g. Rec. 601.
+       Matrix3d rgb_to_ycbcr;
+       rgb_to_ycbcr(0,0) = coeff[0];
+       rgb_to_ycbcr(0,1) = coeff[1];
+       rgb_to_ycbcr(0,2) = coeff[2];
+
+       float cb_fac = (224.0 / 219.0) / (coeff[0] + coeff[1] + 1.0f - coeff[2]);
+       rgb_to_ycbcr(1,0) = -coeff[0] * cb_fac;
+       rgb_to_ycbcr(1,1) = -coeff[1] * cb_fac;
+       rgb_to_ycbcr(1,2) = (1.0f - coeff[2]) * cb_fac;
+
+       float cr_fac = (224.0 / 219.0) / (1.0f - coeff[0] + coeff[1] + coeff[2]);
+       rgb_to_ycbcr(2,0) = (1.0f - coeff[0]) * cr_fac;
+       rgb_to_ycbcr(2,1) = -coeff[1] * cr_fac;
+       rgb_to_ycbcr(2,2) = -coeff[2] * cr_fac;
+
+       // Inverting the matrix gives us what we need to go from YCbCr back to RGB.
+       *ycbcr_to_rgb = rgb_to_ycbcr.inverse();
+
+       // Fold in the scaling.
+       *ycbcr_to_rgb *= Map<const Vector3d>(scale).asDiagonal();
+}
+
 }  // namespace
 
 YCbCrInput::YCbCrInput(const ImageFormat &image_format,
@@ -65,7 +140,6 @@ YCbCrInput::YCbCrInput(const ImageFormat &image_format,
                        unsigned width, unsigned height)
        : image_format(image_format),
          ycbcr_format(ycbcr_format),
-         needs_mipmaps(false),
          width(width),
          height(height),
          resource_pool(NULL)
@@ -84,8 +158,6 @@ YCbCrInput::YCbCrInput(const ImageFormat &image_format,
        heights[2] = height / ycbcr_format.chroma_subsampling_y;
 
        pixel_data[0] = pixel_data[1] = pixel_data[2] = NULL;
-
-       register_int("needs_mipmaps", &needs_mipmaps);
 }
 
 YCbCrInput::~YCbCrInput()
@@ -143,100 +215,26 @@ void YCbCrInput::set_gl_state(GLuint glsl_program_num, const string& prefix, uns
 
 string YCbCrInput::output_fragment_shader()
 {
-       float coeff[3], offset[3], scale[3];
-
-       switch (ycbcr_format.luma_coefficients) {
-       case YCBCR_REC_601:
-               // Rec. 601, page 2.
-               coeff[0] = 0.299;
-               coeff[1] = 0.587;
-               coeff[2] = 0.114;
-               break;
-
-       case YCBCR_REC_709:
-               // Rec. 709, page 19.
-               coeff[0] = 0.2126;
-               coeff[1] = 0.7152;
-               coeff[2] = 0.0722;
-               break;
-
-       case YCBCR_REC_2020:
-               // Rec. 2020, page 4.
-               coeff[0] = 0.2627;
-               coeff[1] = 0.6780;
-               coeff[2] = 0.0593;
-               break;
-
-       default:
-               assert(false);
-       }
-
-       if (ycbcr_format.full_range) {
-               offset[0] = 0.0 / 255.0;
-               offset[1] = 128.0 / 255.0;
-               offset[2] = 128.0 / 255.0;
-
-               scale[0] = 1.0;
-               scale[1] = 1.0;
-               scale[2] = 1.0;
-       } else {
-               // Rec. 601, page 4; Rec. 709, page 19; Rec. 2020, page 4.
-               offset[0] = 16.0 / 255.0;
-               offset[1] = 128.0 / 255.0;
-               offset[2] = 128.0 / 255.0;
-
-               scale[0] = 255.0 / 219.0;
-               scale[1] = 255.0 / 224.0;
-               scale[2] = 255.0 / 224.0;
-       }
-
-       // Matrix to convert RGB to YCbCr. See e.g. Rec. 601.
-       Matrix3d rgb_to_ycbcr;
-       rgb_to_ycbcr(0,0) = coeff[0];
-       rgb_to_ycbcr(0,1) = coeff[1];
-       rgb_to_ycbcr(0,2) = coeff[2];
-
-       float cb_fac = (224.0 / 219.0) / (coeff[0] + coeff[1] + 1.0f - coeff[2]);
-       rgb_to_ycbcr(1,0) = -coeff[0] * cb_fac;
-       rgb_to_ycbcr(1,1) = -coeff[1] * cb_fac;
-       rgb_to_ycbcr(1,2) = (1.0f - coeff[2]) * cb_fac;
-
-       float cr_fac = (224.0 / 219.0) / (1.0f - coeff[0] + coeff[1] + coeff[2]);
-       rgb_to_ycbcr(2,0) = (1.0f - coeff[0]) * cr_fac;
-       rgb_to_ycbcr(2,1) = -coeff[1] * cr_fac;
-       rgb_to_ycbcr(2,2) = -coeff[2] * cr_fac;
-
-       // Inverting the matrix gives us what we need to go from YCbCr back to RGB.
-       Matrix3d ycbcr_to_rgb = rgb_to_ycbcr.inverse();
+       float offset[3];
+       Matrix3d ycbcr_to_rgb;
+       compute_ycbcr_matrix(ycbcr_format, offset, &ycbcr_to_rgb);
 
        string frag_shader;
 
        frag_shader = output_glsl_mat3("PREFIX(inv_ycbcr_matrix)", ycbcr_to_rgb);
-
-       char buf[256];
-       sprintf(buf, "const vec3 PREFIX(offset) = vec3(%.8f, %.8f, %.8f);\n",
-               offset[0], offset[1], offset[2]);
-       frag_shader += buf;
-
-       sprintf(buf, "const vec3 PREFIX(scale) = vec3(%.8f, %.8f, %.8f);\n",
-               scale[0], scale[1], scale[2]);
-       frag_shader += buf;
+       frag_shader += output_glsl_vec3("PREFIX(offset)", offset[0], offset[1], offset[2]);
 
        float cb_offset_x = compute_chroma_offset(
                ycbcr_format.cb_x_position, ycbcr_format.chroma_subsampling_x, widths[1]);
        float cb_offset_y = compute_chroma_offset(
                ycbcr_format.cb_y_position, ycbcr_format.chroma_subsampling_y, heights[1]);
-       sprintf(buf, "const vec2 PREFIX(cb_offset) = vec2(%.8f, %.8f);\n",
-               cb_offset_x, cb_offset_y);
-       frag_shader += buf;
+       frag_shader += output_glsl_vec2("PREFIX(cb_offset)", cb_offset_x, cb_offset_y);
 
        float cr_offset_x = compute_chroma_offset(
                ycbcr_format.cr_x_position, ycbcr_format.chroma_subsampling_x, widths[2]);
        float cr_offset_y = compute_chroma_offset(
                ycbcr_format.cr_y_position, ycbcr_format.chroma_subsampling_y, heights[2]);
-       sprintf(buf, "const vec2 PREFIX(cr_offset) = vec2(%.8f, %.8f);\n",
-               cr_offset_x, cr_offset_y);
-       frag_shader += buf;
+       frag_shader += output_glsl_vec2("PREFIX(cr_offset)", cr_offset_x, cr_offset_y);
 
        frag_shader += read_file("ycbcr_input.frag");
        return frag_shader;
@@ -252,4 +250,13 @@ void YCbCrInput::invalidate_pixel_data()
        }
 }
 
+bool YCbCrInput::set_int(const std::string& key, int value)
+{
+       if (key == "needs_mipmaps") {
+               // We currently do not support this.
+               return (value == 0);
+       }
+       return Effect::set_int(key, value);
+}
+
 }  // namespace movit