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 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
  37 {
  38     graph->filters = av_realloc(graph->filters,
  39                                 sizeof(AVFilterContext*) * ++graph->filter_count);
  40
  41     if (!graph->filters)
  42         return -1;
  43
  44     graph->filters[graph->filter_count - 1] = filter;
  45
  46     return 0;
  47 }
  48
  49 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
  50 {
  51     int i;
  52
  53     for(i = 0; i < graph->filter_count; i ++)
  54         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
  55             return graph->filters[i];
  56
  57     return NULL;
  58 }
  59
  60 static int query_formats(AVFilterGraph *graph)
  61 {
  62     int i, j;
  63     int scaler_count = 0;
  64     char inst_name[30];
  65
  66     /* ask all the sub-filters for their supported colorspaces */
  67     for(i = 0; i < graph->filter_count; i ++) {
  68         if(graph->filters[i]->filter->query_formats)
  69             graph->filters[i]->filter->query_formats(graph->filters[i]);
  70         else
  71             avfilter_default_query_formats(graph->filters[i]);
  72     }
  73
  74     /* go through and merge as many format lists as possible */
  75     for(i = 0; i < graph->filter_count; i ++) {
  76         AVFilterContext *filter = graph->filters[i];
  77
  78         for(j = 0; j < filter->input_count; j ++) {
  79             AVFilterLink *link = filter->inputs[j];
  80             if(link && link->in_formats != link->out_formats) {
  81                 if(!avfilter_merge_formats(link->in_formats,
  82                                            link->out_formats)) {
  83                     AVFilterContext *scale;
  84                     /* couldn't merge format lists. auto-insert scale filter */
  85                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
  86                              scaler_count);
  87                     scale =
  88                         avfilter_open(avfilter_get_by_name("scale"),inst_name);
  89
  90                     if(!scale || scale->filter->init(scale, NULL, NULL) ||
  91                                  avfilter_insert_filter(link, scale, 0, 0)) {
  92                         avfilter_destroy(scale);
  93                         return -1;
  94                     }
  95
  96                     if (avfilter_graph_add_filter(graph, scale) < 0)
  97                         return -1;
  98
  99                     scale->filter->query_formats(scale);
 100                     if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
 101                                                scale-> inputs[0]->out_formats)||
 102                        !avfilter_merge_formats(scale->outputs[0]->in_formats,
 103                                                scale->outputs[0]->out_formats))
 104                         return -1;
 105                 }
 106             }
 107         }
 108     }
 109
 110     return 0;
 111 }
 112
 113 static void pick_format(AVFilterLink *link)
 114 {
 115     if(!link || !link->in_formats)
 116         return;
 117
 118     link->in_formats->format_count = 1;
 119     link->format = link->in_formats->formats[0];
 120
 121     avfilter_formats_unref(&link->in_formats);
 122     avfilter_formats_unref(&link->out_formats);
 123 }
 124
 125 static void pick_formats(AVFilterGraph *graph)
 126 {
 127     int i, j;
 128
 129     for(i = 0; i < graph->filter_count; i ++) {
 130         AVFilterContext *filter = graph->filters[i];
 131
 132         for(j = 0; j < filter->input_count; j ++)
 133             pick_format(filter->inputs[j]);
 134         for(j = 0; j < filter->output_count; j ++)
 135             pick_format(filter->outputs[j]);
 136     }
 137 }
 138
 139 int avfilter_graph_config_formats(AVFilterGraph *graph)
 140 {
 141     /* find supported formats from sub-filters, and merge along links */
 142     if(query_formats(graph))
 143         return -1;
 144
 145     /* Once everything is merged, it's possible that we'll still have
 146      * multiple valid colorspace choices. We pick the first one. */
 147     pick_formats(graph);
 148
 149     return 0;
 150 }
 151