Give a more meaningful instance name to auto-inserted scaler
[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
29 void avfilter_destroy_graph(AVFilterGraph *graph)
30 {
31     for(; graph->filter_count > 0; graph->filter_count --)
32         avfilter_destroy(graph->filters[graph->filter_count - 1]);
33     av_freep(&graph->filters);
34 }
35
36 void avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
37 {
38     graph->filters = av_realloc(graph->filters,
39                                 sizeof(AVFilterContext*) * ++graph->filter_count);
40     graph->filters[graph->filter_count - 1] = filter;
41 }
42
43 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
44 {
45     int i;
46
47     for(i = 0; i < graph->filter_count; i ++)
48         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
49             return graph->filters[i];
50
51     return NULL;
52 }
53
54 static int query_formats(AVFilterGraph *graph)
55 {
56     int i, j;
57     int scaler_count = 0;
58     char inst_name[30];
59
60     /* ask all the sub-filters for their supported colorspaces */
61     for(i = 0; i < graph->filter_count; i ++) {
62         if(graph->filters[i]->filter->query_formats)
63             graph->filters[i]->filter->query_formats(graph->filters[i]);
64         else
65             avfilter_default_query_formats(graph->filters[i]);
66     }
67
68     /* go through and merge as many format lists as possible */
69     for(i = 0; i < graph->filter_count; i ++) {
70         AVFilterContext *filter = graph->filters[i];
71
72         for(j = 0; j < filter->input_count; j ++) {
73             AVFilterLink *link = filter->inputs[j];
74             if(link && link->in_formats != link->out_formats) {
75                 if(!avfilter_merge_formats(link->in_formats,
76                                            link->out_formats)) {
77                     AVFilterContext *scale;
78                     /* couldn't merge format lists. auto-insert scale filter */
79                     snprintf(inst_name, 30, "auto-inserted scaler %d",
80                              scaler_count);
81                     scale =
82                         avfilter_open(avfilter_get_by_name("scale"),inst_name);
83
84                     if(!scale || scale->filter->init(scale, NULL, NULL) ||
85                                  avfilter_insert_filter(link, scale, 0, 0)) {
86                         avfilter_destroy(scale);
87                         return -1;
88                     }
89
90                     avfilter_graph_add_filter(graph, scale);
91                     scale->filter->query_formats(scale);
92                     if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
93                                                scale-> inputs[0]->out_formats)||
94                        !avfilter_merge_formats(scale->outputs[0]->in_formats,
95                                                scale->outputs[0]->out_formats))
96                         return -1;
97                 }
98             }
99         }
100     }
101
102     return 0;
103 }
104
105 static void pick_format(AVFilterLink *link)
106 {
107     if(!link || !link->in_formats)
108         return;
109
110     link->in_formats->format_count = 1;
111     link->format = link->in_formats->formats[0];
112
113     avfilter_formats_unref(&link->in_formats);
114     avfilter_formats_unref(&link->out_formats);
115 }
116
117 static void pick_formats(AVFilterGraph *graph)
118 {
119     int i, j;
120
121     for(i = 0; i < graph->filter_count; i ++) {
122         AVFilterContext *filter = graph->filters[i];
123
124         for(j = 0; j < filter->input_count; j ++)
125             pick_format(filter->inputs[j]);
126         for(j = 0; j < filter->output_count; j ++)
127             pick_format(filter->outputs[j]);
128     }
129 }
130
131 int avfilter_graph_config_formats(AVFilterGraph *graph)
132 {
133     /* find supported formats from sub-filters, and merge along links */
134     if(query_formats(graph))
135         return -1;
136
137     /* Once everything is merged, it's possible that we'll still have
138      * multiple valid colorspace choices. We pick the first one. */
139     pick_formats(graph);
140
141     return 0;
142 }
143