FFmpeg: libavfilter/vf_aspect.c Source File

FFmpeg
vf_aspect.c
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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 
39  static const char *const var_names[] = {
40  "w",
41  "h",
42  "a", "dar",
43  "sar",
44  "hsub",
45  "vsub",
46  NULL
47 };
48 
49  enum 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 
59  typedef 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 
70  static 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 
93  static 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 
104  static 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 
113  static 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 
154 static 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 
190 static 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 
201 AVFILTER_DEFINE_CLASS(setdar);
202 
203 static 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 
213 static const AVFilterPad avfilter_vf_setdar_outputs[] = {
214  {
215  .name = "default",
216  .type = AVMEDIA_TYPE_VIDEO,
217  },
218  { NULL }
219 };
220 
221 AVFilter 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 
235 static 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 
262 static 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 
273 AVFILTER_DEFINE_CLASS(setsar);
274 
275 static 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 
285 static const AVFilterPad avfilter_vf_setsar_outputs[] = {
286  {
287  .name = "default",
288  .type = AVMEDIA_TYPE_VIDEO,
289  },
290  { NULL }
291 };
292 
293 AVFilter 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 */
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