684da30380db436ea9142f2af79f3e90e760a4d9
[ffmpeg.git] / libavfilter / avfiltergraph.c
1 /*
2  * Filter graphs
3  * copyright (c) 2007 Bobby Bingham
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21
22 #include <string.h>
23 #include <stddef.h>
24
25 #include "avfilter.h"
26 #include "avfiltergraph.h"
27
28 struct AVFilterGraph {
29     unsigned filter_count;
30     AVFilterContext **filters;
31 };
32
33 AVFilterGraph *avfilter_create_graph(void)
34 {
35     return av_mallocz(sizeof(AVFilterGraph));
36 }
37
38 static void destroy_graph_filters(AVFilterGraph *graph)
39 {
40     for(; graph->filter_count > 0; graph->filter_count --)
41         avfilter_destroy(graph->filters[graph->filter_count - 1]);
42     av_freep(&graph->filters);
43 }
44
45 void avfilter_destroy_graph(AVFilterGraph *graph)
46 {
47     destroy_graph_filters(graph);
48     av_free(graph);
49 }
50
51 void avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
52 {
53     graph->filters = av_realloc(graph->filters,
54                                 sizeof(AVFilterContext*) * ++graph->filter_count);
55     graph->filters[graph->filter_count - 1] = filter;
56 }
57
58 static AVFilterContext *create_filter_with_args(char *filter)
59 {
60     AVFilterContext *ret;
61     char *name, *args;
62
63     name = filter;
64     if((args = strchr(filter, '='))) {
65         /* ensure we at least have a name */
66         if(args == filter)
67             return NULL;
68
69         *args ++ = 0;
70     }
71
72     av_log(NULL, AV_LOG_INFO, "creating filter \"%s\" with args \"%s\"\n",
73            name, args ? args : "(none)");
74
75     if((ret = avfilter_create_by_name(name, NULL))) {
76         if(avfilter_init_filter(ret, args)) {
77             av_log(NULL, AV_LOG_ERROR, "error initializing filter!\n");
78             avfilter_destroy(ret);
79             ret = NULL;
80         }
81     } else av_log(NULL, AV_LOG_ERROR, "error creating filter!\n");
82
83     return ret;
84 }
85
86 int avfilter_graph_load_chain(AVFilterGraph *graph,
87                               unsigned count, char **filter_list,
88                               AVFilterContext **first, AVFilterContext **last)
89 {
90     unsigned i;
91     AVFilterContext *filters[2] = {NULL,NULL};
92
93     for(i = 0; i < count; i ++) {
94         if(!(filters[1] = create_filter_with_args(filter_list[i])))
95             goto fail;
96         if(i == 0) {
97             if(first) *first = filters[1];
98         } else {
99             if(avfilter_link(filters[0], 0, filters[1], 0)) {
100                 av_log(NULL, AV_LOG_ERROR, "error linking filters!\n");
101                 goto fail;
102             }
103         }
104         avfilter_graph_add_filter(graph, filters[1]);
105         filters[0] = filters[1];
106     }
107
108     if(last) *last = filters[1];
109     return 0;
110
111 fail:
112     destroy_graph_filters(graph);
113     if(first) *first = NULL;
114     if(last)  *last  = NULL;
115     return -1;
116 }
117