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     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