1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/*
* Copyright (c) 2007 Bobby Bingham
*
* 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 <stdint.h>
#include "scale_eval.h"
#include "libavutil/eval.h"
#include "libavutil/mathematics.h"
#include "libavutil/pixdesc.h"
static const char *const var_names[] = {
"in_w", "iw",
"in_h", "ih",
"out_w", "ow",
"out_h", "oh",
"a",
"sar",
"dar",
"hsub",
"vsub",
"ohsub",
"ovsub",
NULL
};
enum var_name {
VAR_IN_W, VAR_IW,
VAR_IN_H, VAR_IH,
VAR_OUT_W, VAR_OW,
VAR_OUT_H, VAR_OH,
VAR_A,
VAR_SAR,
VAR_DAR,
VAR_HSUB,
VAR_VSUB,
VAR_OHSUB,
VAR_OVSUB,
VARS_NB
};
int ff_scale_eval_dimensions(void *log_ctx,
const char *w_expr, const char *h_expr,
AVFilterLink *inlink, AVFilterLink *outlink,
int *ret_w, int *ret_h)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
const char *expr;
int eval_w, eval_h;
int ret;
double var_values[VARS_NB], res;
var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
var_values[VAR_A] = (double) inlink->w / inlink->h;
var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
(double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
/* evaluate width and height */
av_expr_parse_and_eval(&res, (expr = w_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, log_ctx);
eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res;
if ((ret = av_expr_parse_and_eval(&res, (expr = h_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0)
goto fail;
eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = (int) res == 0 ? inlink->h : (int) res;
/* evaluate again the width, as it may depend on the output height */
if ((ret = av_expr_parse_and_eval(&res, (expr = w_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0)
goto fail;
eval_w = (int) res == 0 ? inlink->w : (int) res;
*ret_w = eval_w;
*ret_h = eval_h;
return 0;
fail:
av_log(log_ctx, AV_LOG_ERROR,
"Error when evaluating the expression '%s'.\n"
"Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
expr, w_expr, h_expr);
return ret;
}
int ff_scale_adjust_dimensions(AVFilterLink *inlink,
int *ret_w, int *ret_h,
int force_original_aspect_ratio, int force_divisible_by)
{
int64_t w, h;
int factor_w, factor_h;
w = *ret_w;
h = *ret_h;
/* Check if it is requested that the result has to be divisible by some
* factor (w or h = -n with n being the factor). */
factor_w = 1;
factor_h = 1;
if (w < -1) {
factor_w = -w;
}
if (h < -1) {
factor_h = -h;
}
if (w < 0 && h < 0) {
w = inlink->w;
h = inlink->h;
}
/* Make sure that the result is divisible by the factor we determined
* earlier. If no factor was set, nothing will happen as the default
* factor is 1 */
if (w < 0)
w = av_rescale(h, inlink->w, inlink->h * factor_w) * factor_w;
if (h < 0)
h = av_rescale(w, inlink->h, inlink->w * factor_h) * factor_h;
/* Note that force_original_aspect_ratio may overwrite the previous set
* dimensions so that it is not divisible by the set factors anymore
* unless force_divisible_by is defined as well */
if (force_original_aspect_ratio) {
// Including force_divisible_by here rounds to the nearest multiple of it.
int64_t tmp_w = av_rescale(h, inlink->w, inlink->h * (int64_t)force_divisible_by)
* force_divisible_by;
int64_t tmp_h = av_rescale(w, inlink->h, inlink->w * (int64_t)force_divisible_by)
* force_divisible_by;
if (force_original_aspect_ratio == 1) {
w = FFMIN(tmp_w, w);
h = FFMIN(tmp_h, h);
if (force_divisible_by > 1) {
// round down in case provided w or h is not divisible.
w = w / force_divisible_by * force_divisible_by;
h = h / force_divisible_by * force_divisible_by;
}
} else {
w = FFMAX(tmp_w, w);
h = FFMAX(tmp_h, h);
if (force_divisible_by > 1) {
// round up in case provided w or h is not divisible.
w = (w + force_divisible_by - 1) / force_divisible_by * force_divisible_by;
h = (h + force_divisible_by - 1) / force_divisible_by * force_divisible_by;
}
}
}
if ((int32_t)w != w || (int32_t)h != h)
return AVERROR(EINVAL);
*ret_w = w;
*ret_h = h;
return 0;
}
|
