FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/scale_eval.c
Date: 2026-04-20 20:24:43
Exec Total Coverage
Lines: 16 72 22.2%
Functions: 1 2 50.0%
Branches: 9 44 20.5%

Line Branch Exec Source
1 /*
2 * Copyright (c) 2007 Bobby Bingham
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <stdint.h>
22 #include "scale_eval.h"
23 #include "libavutil/eval.h"
24 #include "libavutil/mathematics.h"
25 #include "libavutil/pixdesc.h"
26
27 static const char *const var_names[] = {
28 "in_w", "iw",
29 "in_h", "ih",
30 "out_w", "ow",
31 "out_h", "oh",
32 "a",
33 "sar",
34 "dar",
35 "hsub",
36 "vsub",
37 "ohsub",
38 "ovsub",
39 NULL
40 };
41
42 enum var_name {
43 VAR_IN_W, VAR_IW,
44 VAR_IN_H, VAR_IH,
45 VAR_OUT_W, VAR_OW,
46 VAR_OUT_H, VAR_OH,
47 VAR_A,
48 VAR_SAR,
49 VAR_DAR,
50 VAR_HSUB,
51 VAR_VSUB,
52 VAR_OHSUB,
53 VAR_OVSUB,
54 VARS_NB
55 };
56
57 int ff_scale_eval_dimensions(void *log_ctx,
58 const char *w_expr, const char *h_expr,
59 AVFilterLink *inlink, AVFilterLink *outlink,
60 int *ret_w, int *ret_h)
61 {
62 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
63 const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
64 const char *expr;
65 int eval_w, eval_h;
66 int ret;
67 double var_values[VARS_NB], res;
68
69 var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
70 var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
71 var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
72 var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
73 var_values[VAR_A] = (double) inlink->w / inlink->h;
74 var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
75 (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
76 var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
77 var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
78 var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
79 var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
80 var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
81
82 /* evaluate width and height */
83 av_expr_parse_and_eval(&res, (expr = w_expr),
84 var_names, var_values,
85 NULL, NULL, NULL, NULL, NULL, 0, log_ctx);
86 var_values[VAR_OUT_W] = var_values[VAR_OW] = res == 0 ? inlink->w : trunc(res);
87
88 if ((ret = av_expr_parse_and_eval(&res, (expr = h_expr),
89 var_names, var_values,
90 NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0)
91 goto fail;
92 if (!(res >= INT32_MIN && res <= INT32_MAX)) {
93 ret = AVERROR(EINVAL);
94 goto fail;
95 }
96
97 eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = (int) res == 0 ? inlink->h : (int) res;
98 /* evaluate again the width, as it may depend on the output height */
99 if ((ret = av_expr_parse_and_eval(&res, (expr = w_expr),
100 var_names, var_values,
101 NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0)
102 goto fail;
103 if (!(res >= INT32_MIN && res <= INT32_MAX)) {
104 ret = AVERROR(EINVAL);
105 goto fail;
106 }
107 eval_w = (int) res == 0 ? inlink->w : (int) res;
108
109 *ret_w = eval_w;
110 *ret_h = eval_h;
111
112 return 0;
113
114 fail:
115 av_log(log_ctx, AV_LOG_ERROR,
116 "Error when evaluating the expression '%s'.\n"
117 "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
118 expr, w_expr, h_expr);
119 return ret;
120 }
121
122 6675 int ff_scale_adjust_dimensions(AVFilterLink *inlink,
123 int *ret_w, int *ret_h,
124 int force_original_aspect_ratio, int force_divisible_by,
125 double w_adj)
126 {
127 int64_t w, h;
128 int64_t factor_w, factor_h;
129
130 6675 w = *ret_w;
131 6675 h = *ret_h;
132
133 /* Check if it is requested that the result has to be divisible by some
134 * factor (w or h = -n with n being the factor). */
135 6675 factor_w = 1;
136 6675 factor_h = 1;
137
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6675 if (w < -1) {
138 factor_w = -w;
139 }
140
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6675 if (h < -1) {
141 factor_h = -h;
142 }
143
144
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6675 if (w < 0 && h < 0) {
145 w = inlink->w * w_adj;
146 h = inlink->h;
147 }
148
149 /* Make sure that the result is divisible by the factor we determined
150 * earlier. If no factor was set, nothing will happen as the default
151 * factor is 1 */
152
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6675 if (w < 0)
153 w = av_rescale(h, inlink->w * w_adj, inlink->h * factor_w) * factor_w;
154
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6675 if (h < 0)
155 1 h = av_rescale(w, inlink->h, inlink->w * w_adj * factor_h) * factor_h;
156
157 /* Note that force_original_aspect_ratio may overwrite the previous set
158 * dimensions so that it is not divisible by the set factors anymore
159 * unless force_divisible_by is defined as well */
160
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6675 if (force_original_aspect_ratio != SCALE_FORCE_OAR_DISABLE) {
161 // Including force_divisible_by here rounds to the nearest multiple of it.
162 int64_t tmp_w = av_rescale(h, inlink->w * w_adj, inlink->h * (int64_t)force_divisible_by)
163 * force_divisible_by;
164 int64_t tmp_h = av_rescale(w, inlink->h, inlink->w * w_adj * (int64_t)force_divisible_by)
165 * force_divisible_by;
166
167 if (force_original_aspect_ratio == SCALE_FORCE_OAR_DECREASE) {
168 w = FFMIN(tmp_w, w);
169 h = FFMIN(tmp_h, h);
170 if (force_divisible_by > 1) {
171 // round down in case provided w or h is not divisible.
172 w = w / force_divisible_by * force_divisible_by;
173 h = h / force_divisible_by * force_divisible_by;
174 }
175 } else { // SCALE_FORCE_OAR_INCREASE
176 w = FFMAX(tmp_w, w);
177 h = FFMAX(tmp_h, h);
178 if (force_divisible_by > 1) {
179 // round up in case provided w or h is not divisible.
180 w = (w + force_divisible_by - 1) / force_divisible_by * force_divisible_by;
181 h = (h + force_divisible_by - 1) / force_divisible_by * force_divisible_by;
182 }
183 }
184 }
185
186
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6675 if ((int32_t)w != w || (int32_t)h != h)
187 return AVERROR(EINVAL);
188
189 6675 *ret_w = w;
190 6675 *ret_h = h;
191
192 6675 return 0;
193 }
194