76 lines
2.1 KiB
C
76 lines
2.1 KiB
C
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/*
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* Copyright (c) 2005 Robert Edele <yartrebo@earthlink.net>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "bbox.h"
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int ff_calculate_bounding_box(FFBoundingBox *bbox,
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const uint8_t *data, int linesize, int w, int h,
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int min_val)
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{
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int x, y;
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int start_x;
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int start_y;
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int end_x;
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int end_y;
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const uint8_t *line;
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/* left bound */
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for (start_x = 0; start_x < w; start_x++)
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for (y = 0; y < h; y++)
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if ((data[y * linesize + start_x] > min_val))
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goto outl;
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outl:
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if (start_x == w) /* no points found */
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return 0;
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/* right bound */
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for (end_x = w - 1; end_x >= start_x; end_x--)
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for (y = 0; y < h; y++)
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if ((data[y * linesize + end_x] > min_val))
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goto outr;
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outr:
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/* top bound */
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line = data;
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for (start_y = 0; start_y < h; start_y++) {
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for (x = 0; x < w; x++)
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if (line[x] > min_val)
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goto outt;
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line += linesize;
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}
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outt:
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/* bottom bound */
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line = data + (h-1)*linesize;
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for (end_y = h - 1; end_y >= start_y; end_y--) {
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for (x = 0; x < w; x++)
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if (line[x] > min_val)
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goto outb;
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line -= linesize;
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}
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outb:
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bbox->x1 = start_x;
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bbox->y1 = start_y;
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bbox->x2 = end_x;
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bbox->y2 = end_y;
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return 1;
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}
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