1/*
2 * Copyright (c) 2010 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/**
22 * @file
23 * aspect ratio modification video filters
24 */
25
26#include <float.h>
27
28#include "libavutil/common.h"
29#include "libavutil/eval.h"
30#include "libavutil/mathematics.h"
31#include "libavutil/opt.h"
32#include "libavutil/parseutils.h"
33#include "libavutil/pixdesc.h"
34
35#include "avfilter.h"
36#include "internal.h"
37#include "video.h"
38
39static const char *const var_names[] = {
40    "w",
41    "h",
42    "a", "dar",
43    "sar",
44    "hsub",
45    "vsub",
46    NULL
47};
48
49enum var_name {
50    VAR_W,
51    VAR_H,
52    VAR_A, VAR_DAR,
53    VAR_SAR,
54    VAR_HSUB,
55    VAR_VSUB,
56    VARS_NB
57};
58
59typedef struct AspectContext {
60    const AVClass *class;
61    AVRational dar;
62    AVRational sar;
63    int max;
64#if FF_API_OLD_FILTER_OPTS
65    float aspect_den;
66#endif
67    char *ratio_expr;
68} AspectContext;
69
70static av_cold int init(AVFilterContext *ctx)
71{
72    AspectContext *s = ctx->priv;
73    int ret;
74
75#if FF_API_OLD_FILTER_OPTS
76    if (s->ratio_expr && s->aspect_den > 0) {
77        double num;
78        av_log(ctx, AV_LOG_WARNING,
79               "num:den syntax is deprecated, please use num/den or named options instead\n");
80        ret = av_expr_parse_and_eval(&num, s->ratio_expr, NULL, NULL,
81                                     NULL, NULL, NULL, NULL, NULL, 0, ctx);
82        if (ret < 0) {
83            av_log(ctx, AV_LOG_ERROR, "Unable to parse ratio numerator \"%s\"\n", s->ratio_expr);
84            return AVERROR(EINVAL);
85        }
86        s->sar = s->dar = av_d2q(num / s->aspect_den, s->max);
87    }
88#endif
89
90    return 0;
91}
92
93static int filter_frame(AVFilterLink *link, AVFrame *frame)
94{
95    AspectContext *s = link->dst->priv;
96
97    frame->sample_aspect_ratio = s->sar;
98    return ff_filter_frame(link->dst->outputs[0], frame);
99}
100
101#define OFFSET(x) offsetof(AspectContext, x)
102#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
103
104static inline void compute_dar(AVRational *dar, AVRational sar, int w, int h)
105{
106    if (sar.num && sar.den) {
107        av_reduce(&dar->num, &dar->den, sar.num * w, sar.den * h, INT_MAX);
108    } else {
109        av_reduce(&dar->num, &dar->den, w, h, INT_MAX);
110    }
111}
112
113static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
114{
115    AVFilterContext *ctx = inlink->dst;
116    AspectContext *s = inlink->dst->priv;
117    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
118    double var_values[VARS_NB], res;
119    int ret;
120
121    var_values[VAR_W]     = inlink->w;
122    var_values[VAR_H]     = inlink->h;
123    var_values[VAR_A]     = (double) inlink->w / inlink->h;
124    var_values[VAR_SAR]   = inlink->sample_aspect_ratio.num ?
125        (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
126    var_values[VAR_DAR]   = var_values[VAR_A] * var_values[VAR_SAR];
127    var_values[VAR_HSUB]  = 1 << desc->log2_chroma_w;
128    var_values[VAR_VSUB]  = 1 << desc->log2_chroma_h;
129
130    /* evaluate new aspect ratio*/
131    ret = av_expr_parse_and_eval(&res, s->ratio_expr,
132                                      var_names, var_values,
133                                      NULL, NULL, NULL, NULL, NULL, 0, ctx);
134    if (ret < 0) {
135        ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);
136    } else
137        *aspect_ratio = av_d2q(res, s->max);
138
139    if (ret < 0) {
140        av_log(ctx, AV_LOG_ERROR,
141               "Error when evaluating the expression '%s'\n", s->ratio_expr);
142        return ret;
143    }
144    if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {
145        av_log(ctx, AV_LOG_ERROR,
146                "Invalid string '%s' for aspect ratio\n", s->ratio_expr);
147        return AVERROR(EINVAL);
148    }
149    return 0;
150}
151
152#if CONFIG_SETDAR_FILTER
153
154static int setdar_config_props(AVFilterLink *inlink)
155{
156    AspectContext *s = inlink->dst->priv;
157    AVRational dar;
158    AVRational old_dar;
159    AVRational old_sar = inlink->sample_aspect_ratio;
160    int ret;
161
162#if FF_API_OLD_FILTER_OPTS
163    if (!(s->ratio_expr && s->aspect_den > 0)) {
164#endif
165    if ((ret = get_aspect_ratio(inlink, &s->dar)))
166        return ret;
167#if FF_API_OLD_FILTER_OPTS
168    }
169#endif
170
171    if (s->dar.num && s->dar.den) {
172        av_reduce(&s->sar.num, &s->sar.den,
173                   s->dar.num * inlink->h,
174                   s->dar.den * inlink->w, INT_MAX);
175        inlink->sample_aspect_ratio = s->sar;
176        dar = s->dar;
177    } else {
178        inlink->sample_aspect_ratio = (AVRational){ 1, 1 };
179        dar = (AVRational){ inlink->w, inlink->h };
180    }
181
182    compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
183    av_log(inlink->dst, AV_LOG_VERBOSE, "w:%d h:%d dar:%d/%d sar:%d/%d -> dar:%d/%d sar:%d/%d\n",
184           inlink->w, inlink->h, old_dar.num, old_dar.den, old_sar.num, old_sar.den,
185           dar.num, dar.den, inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den);
186
187    return 0;
188}
189
190static const AVOption setdar_options[] = {
191    { "dar",   "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
192    { "ratio", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
193    { "r",     "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
194#if FF_API_OLD_FILTER_OPTS
195    { "dar_den", NULL, OFFSET(aspect_den), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },
196#endif
197    { "max",   "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
198    { NULL }
199};
200
201AVFILTER_DEFINE_CLASS(setdar);
202
203static const AVFilterPad avfilter_vf_setdar_inputs[] = {
204    {
205        .name         = "default",
206        .type         = AVMEDIA_TYPE_VIDEO,
207        .config_props = setdar_config_props,
208        .filter_frame = filter_frame,
209    },
210    { NULL }
211};
212
213static const AVFilterPad avfilter_vf_setdar_outputs[] = {
214    {
215        .name = "default",
216        .type = AVMEDIA_TYPE_VIDEO,
217    },
218    { NULL }
219};
220
221AVFilter ff_vf_setdar = {
222    .name        = "setdar",
223    .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),
224    .init        = init,
225    .priv_size   = sizeof(AspectContext),
226    .priv_class  = &setdar_class,
227    .inputs      = avfilter_vf_setdar_inputs,
228    .outputs     = avfilter_vf_setdar_outputs,
229};
230
231#endif /* CONFIG_SETDAR_FILTER */
232
233#if CONFIG_SETSAR_FILTER
234
235static int setsar_config_props(AVFilterLink *inlink)
236{
237    AspectContext *s = inlink->dst->priv;
238    AVRational old_sar = inlink->sample_aspect_ratio;
239    AVRational old_dar, dar;
240    int ret;
241
242#if FF_API_OLD_FILTER_OPTS
243    if (!(s->ratio_expr && s->aspect_den > 0)) {
244#endif
245    if ((ret = get_aspect_ratio(inlink, &s->sar)))
246        return ret;
247#if FF_API_OLD_FILTER_OPTS
248    }
249#endif
250
251    inlink->sample_aspect_ratio = s->sar;
252
253    compute_dar(&old_dar, old_sar, inlink->w, inlink->h);
254    compute_dar(&dar, s->sar, inlink->w, inlink->h);
255    av_log(inlink->dst, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d dar:%d/%d -> sar:%d/%d dar:%d/%d\n",
256           inlink->w, inlink->h, old_sar.num, old_sar.den, old_dar.num, old_dar.den,
257           inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den, dar.num, dar.den);
258
259    return 0;
260}
261
262static const AVOption setsar_options[] = {
263    { "sar",   "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
264    { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
265    { "r",     "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
266#if FF_API_OLD_FILTER_OPTS
267    { "sar_den", NULL, OFFSET(aspect_den), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },
268#endif
269    { "max",   "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },
270    { NULL }
271};
272
273AVFILTER_DEFINE_CLASS(setsar);
274
275static const AVFilterPad avfilter_vf_setsar_inputs[] = {
276    {
277        .name         = "default",
278        .type         = AVMEDIA_TYPE_VIDEO,
279        .config_props = setsar_config_props,
280        .filter_frame = filter_frame,
281    },
282    { NULL }
283};
284
285static const AVFilterPad avfilter_vf_setsar_outputs[] = {
286    {
287        .name = "default",
288        .type = AVMEDIA_TYPE_VIDEO,
289    },
290    { NULL }
291};
292
293AVFilter ff_vf_setsar = {
294    .name        = "setsar",
295    .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),
296    .init        = init,
297    .priv_size   = sizeof(AspectContext),
298    .priv_class  = &setsar_class,
299    .inputs      = avfilter_vf_setsar_inputs,
300    .outputs     = avfilter_vf_setsar_outputs,
301};
302
303#endif /* CONFIG_SETSAR_FILTER */
304