aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/vf_aspect.c
blob: 4c9363955476563fb289ad5a3891789ac11f3bc0 (plain) (blame)
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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
/*
 * Copyright (c) 2010 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
 */

/**
 * @file
 * aspect ratio modification video filters
 */

#include <float.h>

#include "libavutil/common.h"
#include "libavutil/eval.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"

#include "avfilter.h"
#include "internal.h"
#include "video.h"

static const char *const var_names[] = {
    "w",
    "h",
    "a", "dar",
    "sar",
    "hsub",
    "vsub",
    NULL
};

enum var_name {
    VAR_W,
    VAR_H,
    VAR_A, VAR_DAR,
    VAR_SAR,
    VAR_HSUB,
    VAR_VSUB,
    VARS_NB
};

typedef struct AspectContext {
    const AVClass *class;
    AVRational dar;
    AVRational sar;
    int max;
    char *ratio_expr;
} AspectContext;

static int filter_frame(AVFilterLink *link, AVFrame *frame)
{
    AspectContext *s = link->dst->priv;

    frame->sample_aspect_ratio = s->sar;
    return ff_filter_frame(link->dst->outputs[0], frame);
}

#define OFFSET(x) offsetof(AspectContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

static inline void compute_dar(AVRational *dar, AVRational sar, int w, int h)
{
    if (sar.num && sar.den) {
        av_reduce(&dar->num, &dar->den, sar.num * w, sar.den * h, INT_MAX);
    } else {
        av_reduce(&dar->num, &dar->den, w, h, INT_MAX);
    }
}

static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
{
    AVFilterContext *ctx = inlink->dst;
    AspectContext *s = inlink->dst->priv;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
    double var_values[VARS_NB], res;
    int ret;

    var_values[VAR_W]     = inlink->w;
    var_values[VAR_H]     = inlink->h;
    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;

    /* evaluate new aspect ratio*/
    ret = av_expr_parse_and_eval(&res, s->ratio_expr,
                                      var_names, var_values,
                                      NULL, NULL, NULL, NULL, NULL, 0, ctx);
    if (ret < 0) {
        ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);
    } else
        *aspect_ratio = av_d2q(res, s->max);

    if (ret < 0) {
        av_log(ctx, AV_LOG_ERROR,
               "Error when evaluating the expression '%s'\n", s->ratio_expr);
        return ret;
    }
    if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {
        av_log(ctx, AV_LOG_ERROR,
                "Invalid string '%s' for aspect ratio\n", s->ratio_expr);
        return AVERROR(EINVAL);
    }
    return 0;
}

#if CONFIG_SETDAR_FILTER

static int setdar_config_props(AVFilterLink *inlink)
{
    AspectContext *s = inlink->dst->priv;
    AVRational dar;
    AVRational old_dar;
    AVRational old_sar = inlink->sample_aspect_ratio;
    int ret;

    if ((ret = get_aspect_ratio(inlink, &s->dar)))
        return ret;

    if (s->dar.num && s->dar.den) {
        av_reduce(&s->sar.num, &s->sar.den,
                   s->dar.num * inlink->h,
                   s->dar.den * inlink->w, INT_MAX);
        inlink->sample_aspect_ratio = s->sar;
        dar = s->dar;
    } else {
        inlink->sample_aspect_ratio = (AVRational){ 1, 1 };
        dar = (AVRational){ inlink->w, inlink->h };
    }

    compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
    av_log(inlink->dst, AV_LOG_VERBOSE, "w:%d h:%d dar:%d/%d sar:%d/%d -> dar:%d/%d sar:%d/%d\n",
           inlink->w, inlink->h, old_dar.num, old_dar.den, old_sar.num, old_sar.den,
           dar.num, dar.den, inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den);

    return 0;
}

static const AVOption setdar_options[] = {
    { "dar",   "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
    { "ratio", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
    { "r",     "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
    { "max",   "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
    { NULL }
};

AVFILTER_DEFINE_CLASS(setdar);

static const AVFilterPad avfilter_vf_setdar_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .config_props = setdar_config_props,
        .filter_frame = filter_frame,
    },
    { NULL }
};

static const AVFilterPad avfilter_vf_setdar_outputs[] = {
    {
        .name = "default",
        .type = AVMEDIA_TYPE_VIDEO,
    },
    { NULL }
};

AVFilter ff_vf_setdar = {
    .name        = "setdar",
    .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
    .priv_size   = sizeof(AspectContext),
    .priv_class  = &setdar_class,
    .inputs      = avfilter_vf_setdar_inputs,
    .outputs     = avfilter_vf_setdar_outputs,
};

#endif /* CONFIG_SETDAR_FILTER */

#if CONFIG_SETSAR_FILTER

static int setsar_config_props(AVFilterLink *inlink)
{
    AspectContext *s = inlink->dst->priv;
    AVRational old_sar = inlink->sample_aspect_ratio;
    AVRational old_dar, dar;
    int ret;

    if ((ret = get_aspect_ratio(inlink, &s->sar)))
        return ret;

    inlink->sample_aspect_ratio = s->sar;

    compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
    compute_dar(&dar, s->sar, inlink->w, inlink->h);
    av_log(inlink->dst, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d dar:%d/%d -> sar:%d/%d dar:%d/%d\n",
           inlink->w, inlink->h, old_sar.num, old_sar.den, old_dar.num, old_dar.den,
           inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den, dar.num, dar.den);

    return 0;
}

static const AVOption setsar_options[] = {
    { "sar",   "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
    { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
    { "r",     "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
    { "max",   "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
    { NULL }
};

AVFILTER_DEFINE_CLASS(setsar);

static const AVFilterPad avfilter_vf_setsar_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .config_props = setsar_config_props,
        .filter_frame = filter_frame,
    },
    { NULL }
};

static const AVFilterPad avfilter_vf_setsar_outputs[] = {
    {
        .name = "default",
        .type = AVMEDIA_TYPE_VIDEO,
    },
    { NULL }
};

AVFilter ff_vf_setsar = {
    .name        = "setsar",
    .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
    .priv_size   = sizeof(AspectContext),
    .priv_class  = &setsar_class,
    .inputs      = avfilter_vf_setsar_inputs,
    .outputs     = avfilter_vf_setsar_outputs,
};

#endif /* CONFIG_SETSAR_FILTER */