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/*
* lib4lconvert, video4linux2 format conversion lib
* (C) 2008 Hans de Goede <hdegoede@redhat.com>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Note: original bayer_to_bgr24 code from :
* 1394-Based Digital Camera Control Library
*
* Bayer pattern decoding functions
*
* Written by Damien Douxchamps and Frederic Devernay
*
* Note that the original bayer.c in libdc1394 supports many different
* bayer decode algorithms, for lib4lconvert the one in this file has been
* chosen (and optimized a bit) and the other algorithm's have been removed,
* see bayer.c from libdc1394 for all supported algorithms
*/
#include <string.h>
#include "libv4lconvert-priv.h"
/**************************************************************
* Color conversion functions for cameras that can *
* output raw-Bayer pattern images, such as some Basler and *
* Point Grey camera. Most of the algos presented here come *
* from http://www-ise.stanford.edu/~tingchen/ and have been *
* converted from Matlab to C and extended to all elementary *
* patterns. *
**************************************************************/
/* insprired by OpenCV's Bayer decoding */
static void v4lconvert_border_bayer_line_to_bgr24(
const unsigned char* bayer, const unsigned char* adjacent_bayer,
unsigned char *bgr, int width, int start_with_green, int blue_line)
{
int t0, t1;
if (start_with_green) {
/* First pixel */
if (blue_line) {
*bgr++ = bayer[1];
*bgr++ = bayer[0];
*bgr++ = adjacent_bayer[0];
} else {
*bgr++ = adjacent_bayer[0];
*bgr++ = bayer[0];
*bgr++ = bayer[1];
}
/* Second pixel */
t0 = (bayer[0] + bayer[2] + adjacent_bayer[1] + 1) / 3;
t1 = (adjacent_bayer[0] + adjacent_bayer[2] + 1) >> 1;
if (blue_line) {
*bgr++ = bayer[1];
*bgr++ = t0;
*bgr++ = t1;
} else {
*bgr++ = t1;
*bgr++ = t0;
*bgr++ = bayer[1];
}
bayer++;
adjacent_bayer++;
width -= 2;
} else {
/* First pixel */
t0 = (bayer[1] + adjacent_bayer[0] + 1) >> 1;
if (blue_line) {
*bgr++ = bayer[0];
*bgr++ = t0;
*bgr++ = adjacent_bayer[1];
} else {
*bgr++ = adjacent_bayer[1];
*bgr++ = t0;
*bgr++ = bayer[0];
}
width--;
}
if (blue_line) {
for ( ; width > 2; width -= 2) {
t0 = (bayer[0] + bayer[2] + 1) >> 1;
*bgr++ = t0;
*bgr++ = bayer[1];
*bgr++ = adjacent_bayer[1];
bayer++;
adjacent_bayer++;
t0 = (bayer[0] + bayer[2] + adjacent_bayer[1] + 1) / 3;
t1 = (adjacent_bayer[0] + adjacent_bayer[2] + 1) >> 1;
*bgr++ = bayer[1];
*bgr++ = t0;
*bgr++ = t1;
bayer++;
adjacent_bayer++;
}
} else {
for ( ; width > 2; width -= 2) {
t0 = (bayer[0] + bayer[2] + 1) >> 1;
*bgr++ = adjacent_bayer[1];
*bgr++ = bayer[1];
*bgr++ = t0;
bayer++;
adjacent_bayer++;
t0 = (bayer[0] + bayer[2] + adjacent_bayer[1] + 1) / 3;
t1 = (adjacent_bayer[0] + adjacent_bayer[2] + 1) >> 1;
*bgr++ = t1;
*bgr++ = t0;
*bgr++ = bayer[1];
bayer++;
adjacent_bayer++;
}
}
if (width == 2) {
/* Second to last pixel */
t0 = (bayer[0] + bayer[2] + 1) >> 1;
if (blue_line) {
*bgr++ = t0;
*bgr++ = bayer[1];
*bgr++ = adjacent_bayer[1];
} else {
*bgr++ = adjacent_bayer[1];
*bgr++ = bayer[1];
*bgr++ = t0;
}
/* Last pixel */
t0 = (bayer[1] + adjacent_bayer[2] + 1) >> 1;
if (blue_line) {
*bgr++ = bayer[2];
*bgr++ = t0;
*bgr++ = adjacent_bayer[1];
} else {
*bgr++ = adjacent_bayer[1];
*bgr++ = t0;
*bgr++ = bayer[2];
}
} else {
/* Last pixel */
if (blue_line) {
*bgr++ = bayer[0];
*bgr++ = bayer[1];
*bgr++ = adjacent_bayer[1];
} else {
*bgr++ = adjacent_bayer[1];
*bgr++ = bayer[1];
*bgr++ = bayer[0];
}
}
}
/* From libdc1394, which on turn was based on OpenCV's Bayer decoding */
static void bayer_to_rgbbgr24(const unsigned char *bayer,
unsigned char *bgr, int width, int height, unsigned int pixfmt,
int start_with_green, int blue_line)
{
/* render the first line */
v4lconvert_border_bayer_line_to_bgr24(bayer, bayer + width, bgr, width,
start_with_green, blue_line);
bgr += width * 3;
/* reduce height by 2 because of the special case top/bottom line */
for (height -= 2; height; height--) {
int t0, t1;
/* (width - 2) because of the border */
const unsigned char *bayerEnd = bayer + (width - 2);
if (start_with_green) {
/* OpenCV has a bug in the next line, which was
t0 = (bayer[0] + bayer[width * 2] + 1) >> 1; */
t0 = (bayer[1] + bayer[width * 2 + 1] + 1) >> 1;
/* Write first pixel */
t1 = (bayer[0] + bayer[width * 2] + bayer[width + 1] + 1) / 3;
if (blue_line) {
*bgr++ = t0;
*bgr++ = t1;
*bgr++ = bayer[width];
} else {
*bgr++ = bayer[width];
*bgr++ = t1;
*bgr++ = t0;
}
/* Write second pixel */
t1 = (bayer[width] + bayer[width + 2] + 1) >> 1;
if (blue_line) {
*bgr++ = t0;
*bgr++ = bayer[width + 1];
*bgr++ = t1;
} else {
*bgr++ = t1;
*bgr++ = bayer[width + 1];
*bgr++ = t0;
}
bayer++;
} else {
/* Write first pixel */
t0 = (bayer[0] + bayer[width * 2] + 1) >> 1;
if (blue_line) {
*bgr++ = t0;
*bgr++ = bayer[width];
*bgr++ = bayer[width + 1];
} else {
*bgr++ = bayer[width + 1];
*bgr++ = bayer[width];
*bgr++ = t0;
}
}
if (blue_line) {
for (; bayer <= bayerEnd - 2; bayer += 2) {
t0 = (bayer[0] + bayer[2] + bayer[width * 2] +
bayer[width * 2 + 2] + 2) >> 2;
t1 = (bayer[1] + bayer[width] +
bayer[width + 2] + bayer[width * 2 + 1] +
2) >> 2;
*bgr++ = t0;
*bgr++ = t1;
*bgr++ = bayer[width + 1];
t0 = (bayer[2] + bayer[width * 2 + 2] + 1) >> 1;
t1 = (bayer[width + 1] + bayer[width + 3] +
1) >> 1;
*bgr++ = t0;
*bgr++ = bayer[width + 2];
*bgr++ = t1;
}
} else {
for (; bayer <= bayerEnd - 2; bayer += 2) {
t0 = (bayer[0] + bayer[2] + bayer[width * 2] +
bayer[width * 2 + 2] + 2) >> 2;
t1 = (bayer[1] + bayer[width] +
bayer[width + 2] + bayer[width * 2 + 1] +
2) >> 2;
*bgr++ = bayer[width + 1];
*bgr++ = t1;
*bgr++ = t0;
t0 = (bayer[2] + bayer[width * 2 + 2] + 1) >> 1;
t1 = (bayer[width + 1] + bayer[width + 3] +
1) >> 1;
*bgr++ = t1;
*bgr++ = bayer[width + 2];
*bgr++ = t0;
}
}
if (bayer < bayerEnd) {
/* write second to last pixel */
t0 = (bayer[0] + bayer[2] + bayer[width * 2] +
bayer[width * 2 + 2] + 2) >> 2;
t1 = (bayer[1] + bayer[width] +
bayer[width + 2] + bayer[width * 2 + 1] +
2) >> 2;
if (blue_line) {
*bgr++ = t0;
*bgr++ = t1;
*bgr++ = bayer[width + 1];
} else {
*bgr++ = bayer[width + 1];
*bgr++ = t1;
*bgr++ = t0;
}
/* write last pixel */
t0 = (bayer[2] + bayer[width * 2 + 2] + 1) >> 1;
if (blue_line) {
*bgr++ = t0;
*bgr++ = bayer[width + 2];
*bgr++ = bayer[width + 1];
} else {
*bgr++ = bayer[width + 1];
*bgr++ = bayer[width + 2];
*bgr++ = t0;
}
bayer++;
} else {
/* write last pixel */
t0 = (bayer[0] + bayer[width * 2] + 1) >> 1;
t1 = (bayer[1] + bayer[width * 2 + 1] + bayer[width] + 1) / 3;
if (blue_line) {
*bgr++ = t0;
*bgr++ = t1;
*bgr++ = bayer[width + 1];
} else {
*bgr++ = bayer[width + 1];
*bgr++ = t1;
*bgr++ = t0;
}
}
/* skip 2 border pixels */
bayer += 2;
blue_line = !blue_line;
start_with_green = !start_with_green;
}
/* render the last line */
v4lconvert_border_bayer_line_to_bgr24(bayer + width, bayer, bgr, width,
!start_with_green, !blue_line);
}
void v4lconvert_bayer_to_rgb24(const unsigned char *bayer,
unsigned char *bgr, int width, int height, unsigned int pixfmt)
{
bayer_to_rgbbgr24(bayer, bgr, width, height, pixfmt,
pixfmt == V4L2_PIX_FMT_SGBRG8 /* start with green */
|| pixfmt == V4L2_PIX_FMT_SGRBG8,
pixfmt != V4L2_PIX_FMT_SBGGR8 /* blue line */
&& pixfmt != V4L2_PIX_FMT_SGBRG8);
}
void v4lconvert_bayer_to_bgr24(const unsigned char *bayer,
unsigned char *bgr, int width, int height, unsigned int pixfmt)
{
bayer_to_rgbbgr24(bayer, bgr, width, height, pixfmt,
pixfmt == V4L2_PIX_FMT_SGBRG8 /* start with green */
|| pixfmt == V4L2_PIX_FMT_SGRBG8,
pixfmt == V4L2_PIX_FMT_SBGGR8 /* blue line */
|| pixfmt == V4L2_PIX_FMT_SGBRG8);
}
static void v4lconvert_border_bayer_line_to_y(
const unsigned char* bayer, const unsigned char* adjacent_bayer,
unsigned char *y, int width, int start_with_green, int blue_line)
{
int t0, t1;
if (start_with_green) {
/* First pixel */
if (blue_line) {
*y++ = (8453*adjacent_bayer[0] + 16594*bayer[0] + 3223*bayer[1] + 524288)
>> 15;
} else {
*y++ = (8453*bayer[1] + 16594*bayer[0] + 3223*adjacent_bayer[0] + 524288)
>> 15;
}
/* Second pixel */
t0 = bayer[0] + bayer[2] + adjacent_bayer[1];
t1 = adjacent_bayer[0] + adjacent_bayer[2];
if (blue_line) {
*y++ = (4226*t1 + 5531*t0 + 3223*bayer[1] + 524288) >> 15;
} else {
*y++ = (8453*bayer[1] + 5531*t0 + 1611*t1 + 524288) >> 15;
}
bayer++;
adjacent_bayer++;
width -= 2;
} else {
/* First pixel */
t0 = bayer[1] + adjacent_bayer[0];
if (blue_line) {
*y++ = (8453*adjacent_bayer[1] + 8297*t0 + 3223*bayer[0] + 524288)
>> 15;
} else {
*y++ = (8453*bayer[0] + 8297*t0 + 3223*adjacent_bayer[1] + 524288)
>> 15;
}
width--;
}
if (blue_line) {
for ( ; width > 2; width -= 2) {
t0 = bayer[0] + bayer[2];
*y++ = (8453*adjacent_bayer[1] + 16594*bayer[1] + 1611*t0 + 524288)
>> 15;
bayer++;
adjacent_bayer++;
t0 = bayer[0] + bayer[2] + adjacent_bayer[1];
t1 = adjacent_bayer[0] + adjacent_bayer[2];
*y++ = (4226*t1 + 5531*t0 + 3223*bayer[1] + 524288) >> 15;
bayer++;
adjacent_bayer++;
}
} else {
for ( ; width > 2; width -= 2) {
t0 = bayer[0] + bayer[2];
*y++ = (4226*t0 + 16594*bayer[1] + 3223*adjacent_bayer[1] + 524288)
>> 15;
bayer++;
adjacent_bayer++;
t0 = bayer[0] + bayer[2] + adjacent_bayer[1];
t1 = adjacent_bayer[0] + adjacent_bayer[2];
*y++ = (8453*bayer[1] + 5531*t0 + 1611*t1 + 524288) >> 15;
bayer++;
adjacent_bayer++;
}
}
if (width == 2) {
/* Second to last pixel */
t0 = bayer[0] + bayer[2];
if (blue_line) {
*y++ = (8453*adjacent_bayer[1] + 16594*bayer[1] + 1611*t0 + 524288)
>> 15;
} else {
*y++ = (4226*t0 + 16594*bayer[1] + 3223*adjacent_bayer[1] + 524288)
>> 15;
}
/* Last pixel */
t0 = bayer[1] + adjacent_bayer[2];
if (blue_line) {
*y++ = (8453*adjacent_bayer[1] + 8297*t0 + 3223*bayer[2] + 524288)
>> 15;
} else {
*y++ = (8453*bayer[2] + 8297*t0 + 3223*adjacent_bayer[1] + 524288)
>> 15;
}
} else {
/* Last pixel */
if (blue_line) {
*y++ = (8453*adjacent_bayer[1] + 16594*bayer[1] + 3223*bayer[0] + 524288)
>> 15;
} else {
*y++ = (8453*bayer[0] + 16594*bayer[1] + 3223*adjacent_bayer[1] + 524288)
>> 15;
}
}
}
void v4lconvert_bayer_to_yuv420(const unsigned char *bayer, unsigned char *yuv,
int width, int height, unsigned int src_pixfmt, int yvu)
{
int blue_line = 0, start_with_green = 0, x, y;
unsigned char *ydst = yuv;
unsigned char *udst, *vdst;
if (yvu) {
vdst = yuv + width * height;
udst = vdst + width * height / 4;
} else {
udst = yuv + width * height;
vdst = udst + width * height / 4;
}
/* First calculate the u and v planes 2x2 pixels at a time */
switch (src_pixfmt) {
case V4L2_PIX_FMT_SBGGR8:
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 2) {
int b, g, r;
b = bayer[x];
g = bayer[x+1];
g += bayer[x+width];
r = bayer[x+width+1];
*udst++ = (-4878 * r - 4789 * g + 14456 * b + 4210688) >> 15;
*vdst++ = (14456 * r - 6052 * g - 2351 * b + 4210688) >> 15;
}
bayer += 2 * width;
}
blue_line = 1;
break;
case V4L2_PIX_FMT_SRGGB8:
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 2) {
int b, g, r;
r = bayer[x];
g = bayer[x+1];
g += bayer[x+width];
b = bayer[x+width+1];
*udst++ = (-4878 * r - 4789 * g + 14456 * b + 4210688) >> 15;
*vdst++ = (14456 * r - 6052 * g - 2351 * b + 4210688) >> 15;
}
bayer += 2 * width;
}
break;
case V4L2_PIX_FMT_SGBRG8:
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 2) {
int b, g, r;
g = bayer[x];
b = bayer[x+1];
r = bayer[x+width];
g += bayer[x+width+1];
*udst++ = (-4878 * r - 4789 * g + 14456 * b + 4210688) >> 15;
*vdst++ = (14456 * r - 6052 * g - 2351 * b + 4210688) >> 15;
}
bayer += 2 * width;
}
blue_line = 1;
start_with_green = 1;
break;
case V4L2_PIX_FMT_SGRBG8:
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 2) {
int b, g, r;
g = bayer[x];
r = bayer[x+1];
b = bayer[x+width];
g += bayer[x+width+1];
*udst++ = (-4878 * r - 4789 * g + 14456 * b + 4210688) >> 15;
*vdst++ = (14456 * r - 6052 * g - 2351 * b + 4210688) >> 15;
}
bayer += 2 * width;
}
start_with_green = 1;
break;
}
bayer -= width * height;
/* render the first line */
v4lconvert_border_bayer_line_to_y(bayer, bayer + width, ydst, width,
start_with_green, blue_line);
ydst += width;
/* reduce height by 2 because of the border */
for (height -= 2; height; height--) {
int t0, t1;
/* (width - 2) because of the border */
const unsigned char *bayerEnd = bayer + (width - 2);
if (start_with_green) {
t0 = bayer[1] + bayer[width * 2 + 1];
/* Write first pixel */
t1 = bayer[0] + bayer[width * 2] + bayer[width + 1];
if (blue_line)
*ydst++ = (8453*bayer[width] + 5516*t1 + 1661*t0 + 524288) >> 15;
else
*ydst++ = (4226*t0 + 5516*t1 + 3223*bayer[width] + 524288) >> 15;
/* Write second pixel */
t1 = bayer[width] + bayer[width + 2];
if (blue_line)
*ydst++ = (4226*t1 + 16594*bayer[width+1] + 1611*t0 + 524288) >> 15;
else
*ydst++ = (4226*t0 + 16594*bayer[width+1] + 1611*t1 + 524288) >> 15;
bayer++;
} else {
/* Write first pixel */
t0 = bayer[0] + bayer[width * 2];
if (blue_line) {
*ydst++ = (8453*bayer[width+1] + 16594*bayer[width] + 1661*t0 +
524288) >> 15;
} else {
*ydst++ = (4226*t0 + 16594*bayer[width] + 3223*bayer[width+1] +
524288) >> 15;
}
}
if (blue_line) {
for (; bayer <= bayerEnd - 2; bayer += 2) {
t0 = bayer[0] + bayer[2] + bayer[width * 2] + bayer[width * 2 + 2];
t1 = bayer[1] + bayer[width] + bayer[width + 2] + bayer[width * 2 + 1];
*ydst++ = (8453*bayer[width+1] + 4148*t1 + 806*t0 + 524288) >> 15;
t0 = bayer[2] + bayer[width * 2 + 2];
t1 = bayer[width + 1] + bayer[width + 3];
*ydst++ = (4226*t1 + 16594*bayer[width+2] + 1611*t0 + 524288) >> 15;
}
} else {
for (; bayer <= bayerEnd - 2; bayer += 2) {
t0 = bayer[0] + bayer[2] + bayer[width * 2] + bayer[width * 2 + 2];
t1 = bayer[1] + bayer[width] + bayer[width + 2] + bayer[width * 2 + 1];
*ydst++ = (2113*t0 + 4148*t1 + 3223*bayer[width+1] + 524288) >> 15;
t0 = bayer[2] + bayer[width * 2 + 2];
t1 = bayer[width + 1] + bayer[width + 3];
*ydst++ = (4226*t0 + 16594*bayer[width+2] + 1611*t1 + 524288) >> 15;
}
}
if (bayer < bayerEnd) {
/* Write second to last pixel */
t0 = bayer[0] + bayer[2] + bayer[width * 2] + bayer[width * 2 + 2];
t1 = bayer[1] + bayer[width] + bayer[width + 2] + bayer[width * 2 + 1];
if (blue_line)
*ydst++ = (8453*bayer[width+1] + 4148*t1 + 806*t0 + 524288) >> 15;
else
*ydst++ = (2113*t0 + 4148*t1 + 3223*bayer[width+1] + 524288) >> 15;
/* write last pixel */
t0 = bayer[2] + bayer[width * 2 + 2];
if (blue_line) {
*ydst++ = (8453*bayer[width+1] + 16594*bayer[width+2] + 1661*t0 +
524288) >> 15;
} else {
*ydst++ = (4226*t0 + 16594*bayer[width+2] + 3223*bayer[width+1] +
524288) >> 15;
}
bayer++;
} else {
/* write last pixel */
t0 = bayer[0] + bayer[width * 2];
t1 = bayer[1] + bayer[width * 2 + 1] + bayer[width];
if (blue_line)
*ydst++ = (8453*bayer[width+1] + 5516*t1 + 1661*t0 + 524288) >> 15;
else
*ydst++ = (4226*t0 + 5516*t1 + 3223*bayer[width+1] + 524288) >> 15;
}
/* skip 2 border pixels */
bayer += 2;
blue_line = !blue_line;
start_with_green = !start_with_green;
}
/* render the last line */
v4lconvert_border_bayer_line_to_y(bayer + width, bayer, ydst, width,
!start_with_green, !blue_line);
}
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