initial commit, 4.5 stable

modules/theora/editor/rgb2yuv.h

@@ -0,0 +1,76 @@
+/**************************************************************************/
+/*  rgb2yuv.h                                                             */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#pragma once
+
+#include "core/typedefs.h"
+
+// For reference, see:
+// - https://stackoverflow.com/a/9467305
+// - https://en.wikipedia.org/wiki/YCbCr#Approximate_8-bit_matrices_for_BT.601
+
+static void _rgb2yuv420(uint8_t *y, uint8_t *u, uint8_t *v, uint8_t *rgb, size_t width, size_t height, size_t pixel_size) {
+	size_t uvpos = 0;
+	size_t i = 0;
+	for (size_t line = 0; line < height; line += 2) {
+		for (size_t x = 0; x < width; x += 2) {
+			uint8_t r = rgb[pixel_size * i];
+			uint8_t g = rgb[pixel_size * i + 1];
+			uint8_t b = rgb[pixel_size * i + 2];
+
+			y[i++] = ((66 * r + 129 * g + 25 * b) >> 8) + 16;
+
+			u[uvpos] = ((-38 * r + -74 * g + 112 * b) >> 8) + 128;
+			v[uvpos] = ((112 * r + -94 * g + -18 * b) >> 8) + 128;
+			uvpos++;
+
+			r = rgb[pixel_size * i];
+			g = rgb[pixel_size * i + 1];
+			b = rgb[pixel_size * i + 2];
+
+			y[i++] = ((66 * r + 129 * g + 25 * b) >> 8) + 16;
+		}
+		for (size_t x = 0; x < width; x += 1) {
+			uint8_t r = rgb[pixel_size * i];
+			uint8_t g = rgb[pixel_size * i + 1];
+			uint8_t b = rgb[pixel_size * i + 2];
+
+			y[i++] = ((66 * r + 129 * g + 25 * b) >> 8) + 16;
+		}
+	}
+}
+
+static void rgb2yuv420(uint8_t *y, uint8_t *u, uint8_t *v, uint8_t *rgb, size_t width, size_t height) {
+	_rgb2yuv420(y, u, v, rgb, width, height, 3);
+}
+
+static void rgba2yuv420(uint8_t *y, uint8_t *u, uint8_t *v, uint8_t *rgba, size_t width, size_t height) {
+	_rgb2yuv420(y, u, v, rgba, width, height, 4);
+}