3 #include "deinterlace_effect.h"
10 DeinterlaceEffect::DeinterlaceEffect()
11 : enable_spatial_interlacing_check(true),
12 current_field_position(TOP),
15 register_int("enable_spatial_interlacing_check", (int *)&enable_spatial_interlacing_check);
16 register_int("current_field_position", (int *)¤t_field_position);
17 register_uniform_float("num_lines", &num_lines);
18 register_uniform_float("inv_width", &inv_width);
19 register_uniform_float("self_offset", &self_offset);
20 register_uniform_float_array("current_offset", current_offset, 2);
21 register_uniform_float_array("other_offset", other_offset, 3);
24 string DeinterlaceEffect::output_fragment_shader()
27 snprintf(buf, sizeof(buf), "#define YADIF_ENABLE_SPATIAL_INTERLACING_CHECK %d\n",
28 enable_spatial_interlacing_check);
29 string frag_shader = buf;
31 frag_shader += read_file("deinterlace_effect.frag");
35 void DeinterlaceEffect::inform_input_size(unsigned input_num, unsigned width, unsigned height)
37 assert(input_num >= 0 && input_num < 5);
38 widths[input_num] = width;
39 heights[input_num] = height;
40 num_lines = height * 2;
43 void DeinterlaceEffect::get_output_size(unsigned *width, unsigned *height,
44 unsigned *virtual_width, unsigned *virtual_height) const
46 assert(widths[0] == widths[1]);
47 assert(widths[1] == widths[2]);
48 assert(widths[2] == widths[3]);
49 assert(widths[3] == widths[4]);
50 assert(heights[0] == heights[1]);
51 assert(heights[1] == heights[2]);
52 assert(heights[2] == heights[3]);
53 assert(heights[3] == heights[4]);
54 *width = *virtual_width = widths[0];
55 *height = *virtual_height = heights[0] * 2;
58 void DeinterlaceEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
60 Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
62 inv_width = 1.0 / widths[0];
64 // Texel centers: t = output texel center for top field, b = for bottom field,
65 // x = the input texel. (The same area is two pixels for output, one for input;
66 // thus the stippled line in the middle.)
78 // Note as usual OpenGL's bottom-left convention.
79 if (current_field_position == 0) {
81 self_offset = -0.5 / num_lines;
84 assert(current_field_position == 1);
85 self_offset = 0.5 / num_lines;
88 // Having now established where the texels lie for the uninterpolated samples,
89 // we can use that to figure out where to sample for the interpolation. Drawing
90 // the fields as what lines they represent, here for three-pixel high fields
91 // with current_field_position == 0 (plus an āoā to mark the pixel we're trying
92 // to interpolate, and ācā for corresponding texel in the other field):
102 // Obviously, for sampling in the current field, we are one half-texel off
103 // compared to <self_offset>, so sampling in the current field is easy:
104 current_offset[0] = self_offset - 0.5 / heights[0];
105 current_offset[1] = self_offset + 0.5 / heights[0];
107 // Now to find the texel in the other fields corresponding to the pixel
108 // we're trying to interpolate, let's realign the diagram above:
117 // So obviously for this case, we need to center on the same place as
118 // current_offset[1] (the texel directly above the o; note again the
119 // bottom-left convention). For the case of current_field_position == 1,
120 // the shift in the alignment goes the other way, and what we want
121 // is current_offset[0] (the texel directly below the o).
122 float center_offset = current_offset[1 - current_field_position];
123 other_offset[0] = center_offset - 1.0 / heights[0];
124 other_offset[1] = center_offset;
125 other_offset[2] = center_offset + 1.0 / heights[0];