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Sourcecode: libv4l version File versions

crop.c

/*

# 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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;
  }
}

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