git.sesse.net Git - ffmpeg/blob - 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     if(!name)
  48         return NULL;
  49
  50     for(i = 0; i < graph->filter_count; i ++)
  51         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
  52             return graph->filters[i];
  53
  54     return NULL;
  55 }
  56
  57 static int query_formats(AVFilterGraph *graph)
  58 {
  59     int i, j;
  60
  61     /* ask all the sub-filters for their supported colorspaces */
  62     for(i = 0; i < graph->filter_count; i ++) {
  63         if(graph->filters[i]->filter->query_formats)
  64             graph->filters[i]->filter->query_formats(graph->filters[i]);
  65         else
  66             avfilter_default_query_formats(graph->filters[i]);
  67     }
  68
  69     /* go through and merge as many format lists as possible */
  70     for(i = 0; i < graph->filter_count; i ++) {
  71         AVFilterContext *filter = graph->filters[i];
  72
  73         for(j = 0; j < filter->input_count; j ++) {
  74             AVFilterLink *link;
  75             if(!(link = filter->inputs[j]))
  76                 continue;
  77             if(link->in_formats != link->out_formats) {
  78                 if(!avfilter_merge_formats(link->in_formats,
  79                                            link->out_formats)) {
  80                     /* couldn't merge format lists. auto-insert scale filter */
  81                     AVFilterContext *scale;
  82
  83                     if(!(scale =
  84                          avfilter_open(avfilter_get_by_name("scale"), NULL)))
  85                         return -1;
  86                     if(scale->filter->init(scale, NULL, NULL) ||
  87                        avfilter_insert_filter(link, scale, 0, 0)) {
  88                         avfilter_destroy(scale);
  89                         return -1;
  90                     }
  91
  92                     avfilter_graph_add_filter(graph, scale);
  93                     scale->filter->query_formats(scale);
  94                     if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
  95                                                scale-> inputs[0]->out_formats)||
  96                        !avfilter_merge_formats(scale->outputs[0]->in_formats,
  97                                                scale->outputs[0]->out_formats))
  98                         return -1;
  99                 }
 100             }
 101         }
 102     }
 103
 104     return 0;
 105 }
 106
 107 static void pick_format(AVFilterLink *link)
 108 {
 109     if(!link || !link->in_formats)
 110         return;
 111
 112     link->in_formats->format_count = 1;
 113     link->format = link->in_formats->formats[0];
 114
 115     avfilter_formats_unref(&link->in_formats);
 116     avfilter_formats_unref(&link->out_formats);
 117 }
 118
 119 static void pick_formats(AVFilterGraph *graph)
 120 {
 121     int i, j;
 122
 123     for(i = 0; i < graph->filter_count; i ++) {
 124         AVFilterContext *filter = graph->filters[i];
 125
 126         for(j = 0; j < filter->input_count; j ++)
 127             pick_format(filter->inputs[j]);
 128         for(j = 0; j < filter->output_count; j ++)
 129             pick_format(filter->outputs[j]);
 130     }
 131 }
 132
 133 int avfilter_graph_config_formats(AVFilterGraph *graph)
 134 {
 135     /* find supported formats from sub-filters, and merge along links */
 136     if(query_formats(graph))
 137         return -1;
 138
 139     /* Once everything is merged, it's possible that we'll still have
 140      * multiple valid colorspace choices. We pick the first one. */
 141     pick_formats(graph);
 142
 143     return 0;
 144 }
 145