/*

# RGB and YUV crop routines

#             (C) 2008 Hans de Goede <hdegoede@redhat.com>

# This program 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 program 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 program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA  02110-1335  USA

 */

#include <string.h>
#include "libv4lconvert-priv.h"


static void v4lconvert_reduceandcrop_rgbbgr24(
		unsigned char *src, unsigned char *dest,
		const struct v4l2_format *src_fmt, const struct v4l2_format *dest_fmt)
{
	int x, y;
	int startx = src_fmt->fmt.pix.width / 2 - dest_fmt->fmt.pix.width;
	int starty = src_fmt->fmt.pix.height / 2 - dest_fmt->fmt.pix.height;

	src += starty * src_fmt->fmt.pix.bytesperline + 3 * startx;

	for (y = 0; y < dest_fmt->fmt.pix.height; y++) {
		unsigned char *mysrc = src;
		for (x = 0; x < dest_fmt->fmt.pix.width; x++) {
			*(dest++) = *(mysrc++);
			*(dest++) = *(mysrc++);
			*(dest++) = *(mysrc++);
			mysrc += 3; /* skip one pixel */
		}
		src += 2 * src_fmt->fmt.pix.bytesperline; /* skip one line */
	}
}

static void v4lconvert_crop_rgbbgr24(unsigned char *src, unsigned char *dest,
		const struct v4l2_format *src_fmt, const struct v4l2_format *dest_fmt)
{
	int x;
	int startx = (src_fmt->fmt.pix.width - dest_fmt->fmt.pix.width) / 2;
	int starty = (src_fmt->fmt.pix.height - dest_fmt->fmt.pix.height) / 2;

	src += starty * src_fmt->fmt.pix.bytesperline + 3 * startx;

	for (x = 0; x < dest_fmt->fmt.pix.height; x++) {
		memcpy(dest, src, dest_fmt->fmt.pix.width * 3);
		src += src_fmt->fmt.pix.bytesperline;
		dest += dest_fmt->fmt.pix.bytesperline;
	}
}

static void v4lconvert_reduceandcrop_yuv420(
		unsigned char *src, unsigned char *dest,
		const struct v4l2_format *src_fmt, const struct v4l2_format *dest_fmt)
{
	int x, y;
	int dest_height_half = dest_fmt->fmt.pix.height / 2;
	int dest_width_half = dest_fmt->fmt.pix.width / 2;
	int startx = (src_fmt->fmt.pix.width / 2 - dest_fmt->fmt.pix.width) & ~1;
	int starty = (src_fmt->fmt.pix.height / 2 - dest_fmt->fmt.pix.height) & ~1;
	unsigned char *mysrc, *mysrc2;

	/* Y */
	mysrc = src + starty * src_fmt->fmt.pix.bytesperline + startx;
	for (y = 0; y < dest_fmt->fmt.pix.height; y++) {
		mysrc2 = mysrc;
		for (x = 0; x < dest_fmt->fmt.pix.width; x++) {
			*(dest++) = *mysrc2;
			mysrc2 += 2; /* skip one pixel */
		}
		mysrc += 2 * src_fmt->fmt.pix.bytesperline; /* skip one line */
	}

	/* U */
	mysrc = src + src_fmt->fmt.pix.height * src_fmt->fmt.pix.bytesperline +
		(starty / 2) * src_fmt->fmt.pix.bytesperline / 2 + startx / 2;
	for (y = 0; y < dest_height_half; y++) {
		mysrc2 = mysrc;
		for (x = 0; x < dest_width_half; x++) {
			*(dest++) = *mysrc2;
			mysrc2 += 2; /* skip one pixel */
		}
		mysrc += src_fmt->fmt.pix.bytesperline ; /* skip one line */
	}

	/* V */
	mysrc = src + src_fmt->fmt.pix.height * src_fmt->fmt.pix.bytesperline * 5 / 4
		+ (starty / 2) * src_fmt->fmt.pix.bytesperline / 2 + startx / 2;
	for (y = 0; y < dest_height_half; y++) {
		mysrc2 = mysrc;
		for (x = 0; x < dest_width_half; x++) {
			*(dest++) = *mysrc2;
			mysrc2 += 2; /* skip one pixel */
		}
		mysrc += src_fmt->fmt.pix.bytesperline ; /* skip one line */
	}
}

static void v4lconvert_crop_yuv420(unsigned char *src, unsigned char *dest,
		const struct v4l2_format *src_fmt, const struct v4l2_format *dest_fmt)
{
	int x;
	int startx = ((src_fmt->fmt.pix.width - dest_fmt->fmt.pix.width) / 2) & ~1;
	int starty = ((src_fmt->fmt.pix.height - dest_fmt->fmt.pix.height) / 2) & ~1;
	unsigned char *mysrc = src + starty * src_fmt->fmt.pix.bytesperline + startx;

	/* Y */
	for (x = 0; x < dest_fmt->fmt.pix.height; x++) {
		memcpy(dest, mysrc, dest_fmt->fmt.pix.width);
		mysrc += src_fmt->fmt.pix.bytesperline;
		dest += dest_fmt->fmt.pix.bytesperline;
	}

	/* U */
	mysrc = src + src_fmt->fmt.pix.height * src_fmt->fmt.pix.bytesperline +
		(starty / 2) * src_fmt->fmt.pix.bytesperline / 2 + startx / 2;
	for (x = 0; x < dest_fmt->fmt.pix.height / 2; x++) {
		memcpy(dest, mysrc, dest_fmt->fmt.pix.width / 2);
		mysrc += src_fmt->fmt.pix.bytesperline / 2;
		dest += dest_fmt->fmt.pix.bytesperline / 2;
	}

	/* V */
	mysrc = src + src_fmt->fmt.pix.height * src_fmt->fmt.pix.bytesperline * 5 / 4
		+ (starty / 2) * src_fmt->fmt.pix.bytesperline / 2 + startx / 2;
	for (x = 0; x < dest_fmt->fmt.pix.height / 2; x++) {
		memcpy(dest, mysrc, dest_fmt->fmt.pix.width / 2);
		mysrc += src_fmt->fmt.pix.bytesperline / 2;
		dest += dest_fmt->fmt.pix.bytesperline / 2;
	}
}

/* Ok, so this is not really cropping, but more the reverse, whatever */
static void v4lconvert_add_border_rgbbgr24(
		unsigned char *src, unsigned char *dest,
		const struct v4l2_format *src_fmt, const struct v4l2_format *dest_fmt)
{
	int y;
	int borderx = (dest_fmt->fmt.pix.width - src_fmt->fmt.pix.width) / 2;
	int bordery = (dest_fmt->fmt.pix.height - src_fmt->fmt.pix.height) / 2;

	for (y = 0; y < bordery; y++) {
		memset(dest, 0, dest_fmt->fmt.pix.width * 3);
		dest += dest_fmt->fmt.pix.bytesperline;
	}

	for (y = 0; y < src_fmt->fmt.pix.height; y++) {
		memset(dest, 0, borderx * 3);
		dest += borderx * 3;

		memcpy(dest, src, src_fmt->fmt.pix.width * 3);
		src += src_fmt->fmt.pix.bytesperline;
		dest += src_fmt->fmt.pix.width * 3;

		memset(dest, 0, borderx * 3);
		dest += dest_fmt->fmt.pix.bytesperline -
			(borderx + src_fmt->fmt.pix.width) * 3;
	}

	for (y = 0; y < bordery; y++) {
		memset(dest, 0, dest_fmt->fmt.pix.width * 3);
		dest += dest_fmt->fmt.pix.bytesperline;
	}
}

static void v4lconvert_add_border_yuv420(
		unsigned char *src, unsigned char *dest,
		const struct v4l2_format *src_fmt, const struct v4l2_format *dest_fmt)
{
	int y;
	int borderx = ((dest_fmt->fmt.pix.width - src_fmt->fmt.pix.width) / 2) & ~1;
	int bordery = ((dest_fmt->fmt.pix.height - src_fmt->fmt.pix.height) / 2) & ~1;

	/* Y */
	for (y = 0; y < bordery; y++) {
		memset(dest, 16, dest_fmt->fmt.pix.width);
		dest += dest_fmt->fmt.pix.bytesperline;
	}

	for (y = 0; y < src_fmt->fmt.pix.height; y++) {
		memset(dest, 16, borderx);
		dest += borderx;

		memcpy(dest, src, src_fmt->fmt.pix.width);
		src += src_fmt->fmt.pix.bytesperline;
		dest += src_fmt->fmt.pix.width;

		memset(dest, 16, borderx);
		dest += dest_fmt->fmt.pix.bytesperline -
			(borderx + src_fmt->fmt.pix.width);
	}

	for (y = 0; y < bordery; y++) {
		memset(dest, 16, dest_fmt->fmt.pix.width);
		dest += dest_fmt->fmt.pix.bytesperline;
	}

	/* U */
	for (y = 0; y < bordery / 2; y++) {
		memset(dest, 128, dest_fmt->fmt.pix.width / 2);
		dest += dest_fmt->fmt.pix.bytesperline / 2;
	}

	for (y = 0; y < src_fmt->fmt.pix.height / 2; y++) {
		memset(dest, 128, borderx / 2);
		dest += borderx / 2;

		memcpy(dest, src, src_fmt->fmt.pix.width / 2);
		src += src_fmt->fmt.pix.bytesperline / 2;
		dest += src_fmt->fmt.pix.width / 2;

		memset(dest, 128, borderx / 2);
		dest += (dest_fmt->fmt.pix.bytesperline -
				(borderx + src_fmt->fmt.pix.width)) / 2;
	}

	for (y = 0; y < bordery / 2; y++) {
		memset(dest, 128, dest_fmt->fmt.pix.width / 2);
		dest += dest_fmt->fmt.pix.bytesperline / 2;
	}

	/* V */
	for (y = 0; y < bordery / 2; y++) {
		memset(dest, 128, dest_fmt->fmt.pix.width / 2);
		dest += dest_fmt->fmt.pix.bytesperline / 2;
	}

	for (y = 0; y < src_fmt->fmt.pix.height / 2; y++) {
		memset(dest, 128, borderx / 2);
		dest += borderx / 2;

		memcpy(dest, src, src_fmt->fmt.pix.width / 2);
		src += src_fmt->fmt.pix.bytesperline / 2;
		dest += src_fmt->fmt.pix.width / 2;

		memset(dest, 128, borderx / 2);
		dest += (dest_fmt->fmt.pix.bytesperline -
				(borderx + src_fmt->fmt.pix.width)) / 2;
	}

	for (y = 0; y < bordery / 2; y++) {
		memset(dest, 128, dest_fmt->fmt.pix.width / 2);
		dest += dest_fmt->fmt.pix.bytesperline / 2;
	}
}

void v4lconvert_crop(unsigned char *src, unsigned char *dest,
		const struct v4l2_format *src_fmt, const struct v4l2_format *dest_fmt)
{
	switch (dest_fmt->fmt.pix.pixelformat) {
	case V4L2_PIX_FMT_RGB24:
	case V4L2_PIX_FMT_BGR24:
		if (src_fmt->fmt.pix.width  <= dest_fmt->fmt.pix.width &&
				src_fmt->fmt.pix.height <= dest_fmt->fmt.pix.height)
			v4lconvert_add_border_rgbbgr24(src, dest, src_fmt, dest_fmt);
		else if (src_fmt->fmt.pix.width  >= 2 * dest_fmt->fmt.pix.width &&
				src_fmt->fmt.pix.height >= 2 * dest_fmt->fmt.pix.height)
			v4lconvert_reduceandcrop_rgbbgr24(src, dest, src_fmt, dest_fmt);
		else
			v4lconvert_crop_rgbbgr24(src, dest, src_fmt, dest_fmt);
		break;

	case V4L2_PIX_FMT_YUV420:
	case V4L2_PIX_FMT_YVU420:
		if (src_fmt->fmt.pix.width  <= dest_fmt->fmt.pix.width &&
				src_fmt->fmt.pix.height <= dest_fmt->fmt.pix.height)
			v4lconvert_add_border_yuv420(src, dest, src_fmt, dest_fmt);
		else if (src_fmt->fmt.pix.width  >= 2 * dest_fmt->fmt.pix.width &&
				src_fmt->fmt.pix.height >= 2 * dest_fmt->fmt.pix.height)
			v4lconvert_reduceandcrop_yuv420(src, dest, src_fmt, dest_fmt);
		else
			v4lconvert_crop_yuv420(src, dest, src_fmt, dest_fmt);
		break;
	}
}