/**
* @file			alg_yuv_to_rgb.h
* @brief		color space conversion definitions
* @author		Patrick Roth - roth@stettbacher.ch
* @copyright	Stettbacher Signal Processing AG
* 
* @remarks
*
* <PRE>
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
* </PRE>
*
*/


/*
 * This code inplements a RGB to YUV color space conversion and is pixel size independent. Including this code at the
 * C-Source file will define the pixel-bit-depth (see color.c).
 */
// static void yuv_to_rgb8(uint8_t *img_rgb, const int32_t *img_yuv, const int height, const int  width, const int pix_max)
// static void yuv_to_rgb16(uint16_t *img_rgb, const int32_t *img_yuv, const int height, const int  width, const int pix_max)
{
	int x, y, index;
	int blue, green, red;
	int val_y, val_u, val_v;
	const int scale_fact = 10;
	
	
	const int green_y = (int)roundf(1.0*(1<<scale_fact));
	const int green_u = (int)roundf(-0.1942*(1<<scale_fact));
	const int green_v = (int)roundf(-0.5094*(1<<scale_fact));
	
	index = 0;
	for(y = 0; y < height; y++) {
		for(x = 0; x < width; x++) {
			
			// save YUV values on stack
			val_y = img_yuv[index];
			val_u = img_yuv[index+1];
			val_v = img_yuv[index+2];
			
			red = val_y + val_v;
			green = (green_y*val_y + green_u*val_u + green_v*val_v) >> scale_fact;
			blue = val_y + val_u;
			
			// range check red
			if(red < 0) 				red = 0;
			else if(red > pix_max)		red = pix_max;
			
			// range check green
			if(green < 0) 				green = 0;
			else if(green > pix_max)	green = pix_max;
			
			// range check blue
			if(blue < 0) 				blue = 0;
			else if(blue > pix_max)		blue = pix_max;
			
			img_rgb[index] = red;
			img_rgb[index+1] = green;
			img_rgb[index+2] = blue;
			
			index += 3;
		}
	}
}