103 lines
4.2 KiB
C
103 lines
4.2 KiB
C
/****************************************************************************
|
|
* graphics/color/nxglib_yuv2rgb.c
|
|
*
|
|
* Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdint.h>
|
|
#include <debug.h>
|
|
#include <fixedmath.h>
|
|
|
|
#include <nuttx/nx/nxglib.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-Processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define b16_P3441 0x0000581a /* 0.344147 */
|
|
#define b16_P7141 0x0000b6d2 /* 0.714142 */
|
|
#define b16_1P402 0x000166ea /* 1.402008 */
|
|
#define b16_1P772 0x0001c5a2 /* 1.722003 */
|
|
#define b16_128P0 0x00800000 /* 128.000000 */
|
|
|
|
/****************************************************************************
|
|
* Private Types
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: nxgl_yuv2rgb
|
|
*
|
|
* Description:
|
|
* Convert 8-bit RGB triplet to 8-bit YUV triplet
|
|
*
|
|
****************************************************************************/
|
|
|
|
void nxgl_yuv2rgb(uint8_t y, uint8_t u, uint8_t v,
|
|
uint8_t *r, uint8_t *g, uint8_t *b)
|
|
{
|
|
b16_t vm128 = itob16(v) - b16_128P0;
|
|
b16_t um128 = itob16(u) - b16_128P0;
|
|
|
|
/* Per the JFIF specification:
|
|
*
|
|
* R = Y + 1.40200 * (V - 128.0)
|
|
* G = Y - 0.34414 * (U - 128.0) - 0.71414 * (V - 128.0)
|
|
* B = Y + 1.77200 * (U - 128.0)
|
|
*/
|
|
|
|
*r = (uint8_t)b16toi(itob16(y) + b16muli(b16_1P402, vm128));
|
|
*g = (uint8_t)b16toi(itob16(y) - b16muli(b16_P3441, um128) - b16muli(b16_P7141, vm128));
|
|
*b = (uint8_t)b16toi(itob16(y) + b16muli(b16_1P772, um128));
|
|
}
|