1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #ifndef AVFILTER_SCALE_EVAL_H
20 #define AVFILTER_SCALE_EVAL_H
21
23
24 enum {
29 };
30
31 /**
32 * Parse and evaluate string expressions for width and height. Upon success,
33 * ff_scale_adjust_dimensions must be called with evaluated width and height
34 * to obtain actual target dimensions.
35 *
36 * Returns 0 upon success, negative value if one of the expressions could
37 * not be parsed or if NaN was the result of their evaluation.
38 */
40 const char *w_expr, const char *h_expr,
42 int *ret_w, int *ret_h);
43
44 /**
45 * Transform evaluated width and height obtained from ff_scale_eval_dimensions
46 * into actual target width and height for scaling. Adjustment can occur if one
47 * or both of the evaluated values are of the form '-n' or if
48 * force_original_aspect_ratio is set. force_divisible_by is used only when
49 * force_original_aspect_ratio is set and must be at least 1.
50 * w_adj is the input SAR when the output dimensions are intended to be square
51 * pixels, else should be 1.
52 *
53 * Returns negative error code on error or non negative on success
54 */
56 int *ret_w, int *ret_h,
57 int force_original_aspect_ratio, int force_divisible_by,
58 double w_adj);
59 #endif