Make avfilter_graph_free() do nothing if graph is NULL.
[ffmpeg.git] / libavfilter / avfiltergraph.c
1 /*
2  * filter graphs
3  * Copyright (c) 2008 Vitor Sessak
4  * Copyright (c) 2007 Bobby Bingham
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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
30 AVFilterGraph *avfilter_graph_alloc(void)
31 {
32     return av_mallocz(sizeof(AVFilterGraph));
33 }
34
35 void avfilter_graph_free(AVFilterGraph *graph)
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 }
44
45 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
46 {
47     AVFilterContext **filters = av_realloc(graph->filters,
48                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
49     if (!filters)
50         return AVERROR(ENOMEM);
51
52     graph->filters = filters;
53     graph->filters[graph->filter_count++] = filter;
54
55     return 0;
56 }
57
58 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
59                                  const char *name, const char *args, void *opaque,
60                                  AVFilterGraph *graph_ctx)
61 {
62     int ret;
63
64     if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
65         goto fail;
66     if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
67         goto fail;
68     if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
69         goto fail;
70     return 0;
71
72 fail:
73     if (*filt_ctx)
74         avfilter_free(*filt_ctx);
75     *filt_ctx = NULL;
76     return ret;
77 }
78
79 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
80 {
81     AVFilterContext *filt;
82     int i, j;
83
84     for (i = 0; i < graph->filter_count; i++) {
85         filt = graph->filters[i];
86
87         for (j = 0; j < filt->input_count; j++) {
88             if (!filt->inputs[j] || !filt->inputs[j]->src) {
89                 av_log(log_ctx, AV_LOG_ERROR,
90                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
91                        filt->input_pads[j].name, filt->name, filt->filter->name);
92                 return -1;
93             }
94         }
95
96         for (j = 0; j < filt->output_count; j++) {
97             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
98                 av_log(log_ctx, AV_LOG_ERROR,
99                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
100                        filt->output_pads[j].name, filt->name, filt->filter->name);
101                 return -1;
102             }
103         }
104     }
105
106     return 0;
107 }
108
109 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
110 {
111     AVFilterContext *filt;
112     int i, ret;
113
114     for (i=0; i < graph->filter_count; i++) {
115         filt = graph->filters[i];
116
117         if (!filt->output_count) {
118             if ((ret = avfilter_config_links(filt)))
119                 return ret;
120         }
121     }
122
123     return 0;
124 }
125
126 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
127 {
128     int i;
129
130     for (i = 0; i < graph->filter_count; i++)
131         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
132             return graph->filters[i];
133
134     return NULL;
135 }
136
137 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
138 {
139     int i, j, ret;
140     int scaler_count = 0;
141     char inst_name[30];
142
143     /* ask all the sub-filters for their supported media formats */
144     for (i = 0; i < graph->filter_count; i++) {
145         if (graph->filters[i]->filter->query_formats)
146             graph->filters[i]->filter->query_formats(graph->filters[i]);
147         else
148             avfilter_default_query_formats(graph->filters[i]);
149     }
150
151     /* go through and merge as many format lists as possible */
152     for (i = 0; i < graph->filter_count; i++) {
153         AVFilterContext *filter = graph->filters[i];
154
155         for (j = 0; j < filter->input_count; j++) {
156             AVFilterLink *link = filter->inputs[j];
157             if (link && link->in_formats != link->out_formats) {
158                 if (!avfilter_merge_formats(link->in_formats,
159                                             link->out_formats)) {
160                     AVFilterContext *scale;
161                     char scale_args[256];
162                     /* couldn't merge format lists. auto-insert scale filter */
163                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
164                              scaler_count++);
165                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
166                     if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
167                                                             inst_name, scale_args, NULL, graph)) < 0)
168                         return ret;
169                     if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
170                         return ret;
171
172                     scale->filter->query_formats(scale);
173                     if (((link = scale-> inputs[0]) &&
174                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
175                         ((link = scale->outputs[0]) &&
176                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
177                         av_log(log_ctx, AV_LOG_ERROR,
178                                "Impossible to convert between the formats supported by the filter "
179                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
180                         return -1;
181                     }
182                 }
183             }
184         }
185     }
186
187     return 0;
188 }
189
190 static void pick_format(AVFilterLink *link)
191 {
192     if (!link || !link->in_formats)
193         return;
194
195     link->in_formats->format_count = 1;
196     link->format = link->in_formats->formats[0];
197
198     avfilter_formats_unref(&link->in_formats);
199     avfilter_formats_unref(&link->out_formats);
200 }
201
202 static void pick_formats(AVFilterGraph *graph)
203 {
204     int i, j;
205
206     for (i = 0; i < graph->filter_count; i++) {
207         AVFilterContext *filter = graph->filters[i];
208
209         for (j = 0; j < filter->input_count; j++)
210             pick_format(filter->inputs[j]);
211         for (j = 0; j < filter->output_count; j++)
212             pick_format(filter->outputs[j]);
213     }
214 }
215
216 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
217 {
218     /* find supported formats from sub-filters, and merge along links */
219     if (query_formats(graph, log_ctx))
220         return -1;
221
222     /* Once everything is merged, it's possible that we'll still have
223      * multiple valid media format choices. We pick the first one. */
224     pick_formats(graph);
225
226     return 0;
227 }
228
229 int avfilter_graph_config(AVFilterGraph *graphctx, AVClass *log_ctx)
230 {
231     int ret;
232
233     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
234         return ret;
235     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
236         return ret;
237     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
238         return ret;
239
240     return 0;
241 }