avfiltergraph.c
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1 /*
2  * filter graphs
3  * Copyright (c) 2008 Vitor Sessak
4  * Copyright (c) 2007 Bobby Bingham
5  *
6  * This file is part of Libav.
7  *
8  * Libav is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * Libav is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include <ctype.h>
24 #include <string.h>
25 
26 #include "avfilter.h"
27 #include "avfiltergraph.h"
28 #include "internal.h"
29 
31 {
32  return av_mallocz(sizeof(AVFilterGraph));
33 }
34 
36 {
37  if (!*graph)
38  return;
39  for (; (*graph)->filter_count > 0; (*graph)->filter_count--)
40  avfilter_free((*graph)->filters[(*graph)->filter_count - 1]);
41  av_freep(&(*graph)->scale_sws_opts);
42  av_freep(&(*graph)->filters);
43  av_freep(graph);
44 }
45 
47 {
49  sizeof(AVFilterContext*) * (graph->filter_count+1));
50  if (!filters)
51  return AVERROR(ENOMEM);
52 
53  graph->filters = filters;
54  graph->filters[graph->filter_count++] = filter;
55 
56  return 0;
57 }
58 
60  const char *name, const char *args, void *opaque,
61  AVFilterGraph *graph_ctx)
62 {
63  int ret;
64 
65  if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
66  goto fail;
67  if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
68  goto fail;
69  if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
70  goto fail;
71  return 0;
72 
73 fail:
74  if (*filt_ctx)
75  avfilter_free(*filt_ctx);
76  *filt_ctx = NULL;
77  return ret;
78 }
79 
81 {
82  AVFilterContext *filt;
83  int i, j;
84 
85  for (i = 0; i < graph->filter_count; i++) {
86  filt = graph->filters[i];
87 
88  for (j = 0; j < filt->input_count; j++) {
89  if (!filt->inputs[j] || !filt->inputs[j]->src) {
90  av_log(log_ctx, AV_LOG_ERROR,
91  "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
92  filt->input_pads[j].name, filt->name, filt->filter->name);
93  return AVERROR(EINVAL);
94  }
95  }
96 
97  for (j = 0; j < filt->output_count; j++) {
98  if (!filt->outputs[j] || !filt->outputs[j]->dst) {
99  av_log(log_ctx, AV_LOG_ERROR,
100  "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
101  filt->output_pads[j].name, filt->name, filt->filter->name);
102  return AVERROR(EINVAL);
103  }
104  }
105  }
106 
107  return 0;
108 }
109 
111 {
112  AVFilterContext *filt;
113  int i, ret;
114 
115  for (i=0; i < graph->filter_count; i++) {
116  filt = graph->filters[i];
117 
118  if (!filt->output_count) {
119  if ((ret = avfilter_config_links(filt)))
120  return ret;
121  }
122  }
123 
124  return 0;
125 }
126 
128 {
129  int i;
130 
131  for (i = 0; i < graph->filter_count; i++)
132  if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
133  return graph->filters[i];
134 
135  return NULL;
136 }
137 
138 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
139 {
140  int i, j, ret;
141  int scaler_count = 0;
142  char inst_name[30];
143 
144  /* ask all the sub-filters for their supported media formats */
145  for (i = 0; i < graph->filter_count; i++) {
146  if (graph->filters[i]->filter->query_formats)
147  graph->filters[i]->filter->query_formats(graph->filters[i]);
148  else
150  }
151 
152  /* go through and merge as many format lists as possible */
153  for (i = 0; i < graph->filter_count; i++) {
154  AVFilterContext *filter = graph->filters[i];
155 
156  for (j = 0; j < filter->input_count; j++) {
157  AVFilterLink *link = filter->inputs[j];
158  if (link && link->in_formats != link->out_formats) {
160  link->out_formats)) {
162  char scale_args[256];
163  /* couldn't merge format lists. auto-insert scale filter */
164  snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
165  scaler_count++);
166  snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
167  if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
168  inst_name, scale_args, NULL, graph)) < 0)
169  return ret;
170  if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
171  return ret;
172 
173  scale->filter->query_formats(scale);
174  if (((link = scale-> inputs[0]) &&
176  ((link = scale->outputs[0]) &&
178  av_log(log_ctx, AV_LOG_ERROR,
179  "Impossible to convert between the formats supported by the filter "
180  "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
181  return AVERROR(EINVAL);
182  }
183  }
184  }
185  }
186  }
187 
188  return 0;
189 }
190 
191 static void pick_format(AVFilterLink *link)
192 {
193  if (!link || !link->in_formats)
194  return;
195 
196  link->in_formats->format_count = 1;
197  link->format = link->in_formats->formats[0];
198 
201 }
202 
203 static void pick_formats(AVFilterGraph *graph)
204 {
205  int i, j;
206 
207  for (i = 0; i < graph->filter_count; i++) {
208  AVFilterContext *filter = graph->filters[i];
209 
210  for (j = 0; j < filter->input_count; j++)
211  pick_format(filter->inputs[j]);
212  for (j = 0; j < filter->output_count; j++)
213  pick_format(filter->outputs[j]);
214  }
215 }
216 
218 {
219  int ret;
220 
221  /* find supported formats from sub-filters, and merge along links */
222  if ((ret = query_formats(graph, log_ctx)) < 0)
223  return ret;
224 
225  /* Once everything is merged, it's possible that we'll still have
226  * multiple valid media format choices. We pick the first one. */
227  pick_formats(graph);
228 
229  return 0;
230 }
231 
232 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
233 {
234  int ret;
235 
236  if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
237  return ret;
238  if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
239  return ret;
240  if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
241  return ret;
242 
243  return 0;
244 }