ffmpeg/libavfilter/bbox.c

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/*
* Copyright (c) 2005 Robert Edele <yartrebo@earthlink.net>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "bbox.h"
#define BBOX(type, name) \
static int bbox_##name(FFBoundingBox *bbox, \
const type *data, int linesize, int w, int h, \
int min_val) \
{ \
int x, y; \
int start_x; \
int start_y; \
int end_x; \
int end_y; \
const type *line; \
\
/* left bound */ \
for (start_x = 0; start_x < w; start_x++) \
for (y = 0; y < h; y++) \
if ((data[y * linesize + start_x] > min_val)) \
goto outl; \
outl: \
if (start_x == w) /* no points found */ \
return 0; \
\
/* right bound */ \
for (end_x = w - 1; end_x >= start_x; end_x--) \
for (y = 0; y < h; y++) \
if ((data[y * linesize + end_x] > min_val)) \
goto outr; \
outr: \
\
/* top bound */ \
line = data; \
for (start_y = 0; start_y < h; start_y++) { \
for (x = 0; x < w; x++) \
if (line[x] > min_val) \
goto outt; \
line += linesize; \
} \
outt: \
\
/* bottom bound */ \
line = data + (h-1)*linesize; \
for (end_y = h - 1; end_y >= start_y; end_y--) { \
for (x = 0; x < w; x++) \
if (line[x] > min_val) \
goto outb; \
line -= linesize; \
} \
outb: \
\
bbox->x1 = start_x; \
bbox->y1 = start_y; \
bbox->x2 = end_x; \
bbox->y2 = end_y; \
return 1; \
}
BBOX(uint8_t, 8)
BBOX(uint16_t, 16)
int ff_calculate_bounding_box(FFBoundingBox *bbox,
const uint8_t *data, int linesize,
int w, int h,
int min_val, int depth)
{
if (depth <= 8)
return bbox_8(bbox, data, linesize, w, h, min_val);
else
return bbox_16(bbox, (const uint16_t *)data, linesize / 2, w, h, min_val);
}