/* * Copyright (C) 2023 Mikhail Burakov. This file is part of streamer. * * streamer is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * streamer is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with streamer. If not, see . */ uniform sampler2D img_input; uniform mediump vec2 chroma_offsets; varying mediump vec2 texcoord; mediump vec2 rgb2chroma(in mediump vec4 rgb) { // mburakov: This hardcodes BT.709 full-range. mediump float y = rgb.r * 0.2126 + rgb.g * 0.7152 + rgb.b * 0.0722; mediump float u = (rgb.b - y) / (2.0 * (1.0 - 0.0722)); mediump float v = (rgb.r - y) / (2.0 * (1.0 - 0.2126)); return vec2(u + 0.5, v + 0.5); } void main() { mediump vec2 sample_points[4]; sample_points[0] = texcoord; sample_points[1] = texcoord + vec2(chroma_offsets.x, 0.0); sample_points[2] = texcoord + vec2(0.0, chroma_offsets.y); sample_points[3] = texcoord + chroma_offsets; mediump vec4 rgb = texture2D(img_input, sample_points[0]) + texture2D(img_input, sample_points[1]) + texture2D(img_input, sample_points[2]) + texture2D(img_input, sample_points[3]); gl_FragColor = vec4(rgb2chroma(rgb / 4.0), 0.0, 1.0); }