]> git.sesse.net Git - movit/blobdiff - ycbcr_input.cpp
Convert an overly cut-and-pasted comment for AlphaDivisionEffect.
[movit] / ycbcr_input.cpp
index 476f083af05d1ad9b5f26c1fd1b9a60a3393738b..091880fdade7f0dd2ee778b9bc74366dc668a637 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>
@@ -8,62 +8,19 @@
 #include "effect_util.h"
 #include "resource_pool.h"
 #include "util.h"
+#include "ycbcr.h"
 #include "ycbcr_input.h"
 
 using namespace Eigen;
 using namespace std;
 
-namespace {
-
-// OpenGL has texel center in (0.5, 0.5), but different formats have
-// chroma in various other places. If luma samples are X, the chroma
-// sample is *, and subsampling is 3x3, the situation with chroma
-// center in (0.5, 0.5) looks approximately like this:
-//
-//   X   X
-//     *   
-//   X   X
-//
-// If, on the other hand, chroma center is in (0.0, 0.5) (common
-// for e.g. MPEG-4), the figure changes to:
-//
-//   X   X
-//   *      
-//   X   X
-//
-// In other words, (0.0, 0.0) means that the chroma sample is exactly
-// co-sited on top of the top-left luma sample. Note, however, that
-// this is _not_ 0.5 texels to the left, since the OpenGL's texel center
-// is in (0.5, 0.5); it is in (0.25, 0.25). In a sense, the four luma samples
-// define a square where chroma position (0.0, 0.0) is in texel position
-// (0.25, 0.25) and chroma position (1.0, 1.0) is in texel position (0.75, 0.75)
-// (the outer border shows the borders of the texel itself, ie. from
-// (0, 0) to (1, 1)):
-//
-//  ---------
-// |         |
-// |  X---X  |
-// |  | * |  |
-// |  X---X  |
-// |         |
-//  ---------
-//
-// Also note that if we have no subsampling, the square will have zero
-// area and the chroma position does not matter at all.
-float compute_chroma_offset(float pos, unsigned subsampling_factor, unsigned resolution)
-{
-       float local_chroma_pos = (0.5 + pos * (subsampling_factor - 1)) / subsampling_factor;
-       return (0.5 - local_chroma_pos) / resolution;
-}
-
-}  // namespace
+namespace movit {
 
 YCbCrInput::YCbCrInput(const ImageFormat &image_format,
                        const YCbCrFormat &ycbcr_format,
                        unsigned width, unsigned height)
        : image_format(image_format),
          ycbcr_format(ycbcr_format),
-         needs_mipmaps(false),
          width(width),
          height(height),
          resource_pool(NULL)
@@ -82,8 +39,6 @@ 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()
@@ -103,7 +58,7 @@ void YCbCrInput::set_gl_state(GLuint glsl_program_num, const string& prefix, uns
 
                if (texture_num[channel] == 0) {
                        // (Re-)upload the texture.
-                       texture_num[channel] = resource_pool->create_2d_texture(GL_LUMINANCE8, widths[channel], heights[channel]);
+                       texture_num[channel] = resource_pool->create_2d_texture(GL_R8, widths[channel], heights[channel]);
                        glBindTexture(GL_TEXTURE_2D, texture_num[channel]);
                        check_error();
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
@@ -114,7 +69,7 @@ void YCbCrInput::set_gl_state(GLuint glsl_program_num, const string& prefix, uns
                        check_error();
                        glPixelStorei(GL_UNPACK_ROW_LENGTH, pitch[channel]);
                        check_error();
-                       glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, widths[channel], heights[channel], GL_LUMINANCE, GL_UNSIGNED_BYTE, pixel_data[channel]);
+                       glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, widths[channel], heights[channel], GL_RED, GL_UNSIGNED_BYTE, pixel_data[channel]);
                        check_error();
                        glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
                        check_error();
@@ -141,100 +96,26 @@ 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;
@@ -249,3 +130,14 @@ 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