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 int avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  50 {
  51     AVFilterContext *filt;
  52     int i, j;
  53
  54     for (i=0; i < graph->filter_count; i++) {
  55         filt = graph->filters[i];
  56
  57         for (j = 0; j < filt->input_count; j++) {
  58             if (!filt->inputs[j] || !filt->inputs[j]->src) {
  59                 av_log(log_ctx, AV_LOG_ERROR,
  60                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
  61                        filt->input_pads[j].name, filt->name, filt->filter->name);
  62                 return -1;
  63             }
  64         }
  65
  66         for (j = 0; j < filt->output_count; j++) {
  67             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
  68                 av_log(log_ctx, AV_LOG_ERROR,
  69                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
  70                        filt->output_pads[j].name, filt->name, filt->filter->name);
  71                 return -1;
  72             }
  73         }
  74     }
  75
  76     return 0;
  77 }
  78
  79 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
  80 {
  81     int i;
  82
  83     for(i = 0; i < graph->filter_count; i ++)
  84         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
  85             return graph->filters[i];
  86
  87     return NULL;
  88 }
  89
  90 static int query_formats(AVFilterGraph *graph)
  91 {
  92     int i, j;
  93     int scaler_count = 0;
  94     char inst_name[30];
  95
  96     /* ask all the sub-filters for their supported colorspaces */
  97     for(i = 0; i < graph->filter_count; i ++) {
  98         if(graph->filters[i]->filter->query_formats)
  99             graph->filters[i]->filter->query_formats(graph->filters[i]);
 100         else
 101             avfilter_default_query_formats(graph->filters[i]);
 102     }
 103
 104     /* go through and merge as many format lists as possible */
 105     for(i = 0; i < graph->filter_count; i ++) {
 106         AVFilterContext *filter = graph->filters[i];
 107
 108         for(j = 0; j < filter->input_count; j ++) {
 109             AVFilterLink *link = filter->inputs[j];
 110             if(link && link->in_formats != link->out_formats) {
 111                 if(!avfilter_merge_formats(link->in_formats,
 112                                            link->out_formats)) {
 113                     AVFilterContext *scale;
 114                     /* couldn't merge format lists. auto-insert scale filter */
 115                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 116                              scaler_count);
 117                     scale =
 118                         avfilter_open(avfilter_get_by_name("scale"),inst_name);
 119
 120                     if(!scale || scale->filter->init(scale, NULL, NULL) ||
 121                                  avfilter_insert_filter(link, scale, 0, 0)) {
 122                         avfilter_destroy(scale);
 123                         return -1;
 124                     }
 125
 126                     if (avfilter_graph_add_filter(graph, scale) < 0)
 127                         return -1;
 128
 129                     scale->filter->query_formats(scale);
 130                     if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
 131                                                scale-> inputs[0]->out_formats)||
 132                        !avfilter_merge_formats(scale->outputs[0]->in_formats,
 133                                                scale->outputs[0]->out_formats))
 134                         return -1;
 135                 }
 136             }
 137         }
 138     }
 139
 140     return 0;
 141 }
 142
 143 static void pick_format(AVFilterLink *link)
 144 {
 145     if(!link || !link->in_formats)
 146         return;
 147
 148     link->in_formats->format_count = 1;
 149     link->format = link->in_formats->formats[0];
 150
 151     avfilter_formats_unref(&link->in_formats);
 152     avfilter_formats_unref(&link->out_formats);
 153 }
 154
 155 static void pick_formats(AVFilterGraph *graph)
 156 {
 157     int i, j;
 158
 159     for(i = 0; i < graph->filter_count; i ++) {
 160         AVFilterContext *filter = graph->filters[i];
 161
 162         for(j = 0; j < filter->input_count; j ++)
 163             pick_format(filter->inputs[j]);
 164         for(j = 0; j < filter->output_count; j ++)
 165             pick_format(filter->outputs[j]);
 166     }
 167 }
 168
 169 int avfilter_graph_config_formats(AVFilterGraph *graph)
 170 {
 171     /* find supported formats from sub-filters, and merge along links */
 172     if(query_formats(graph))
 173         return -1;
 174
 175     /* Once everything is merged, it's possible that we'll still have
 176      * multiple valid colorspace choices. We pick the first one. */
 177     pick_formats(graph);
 178
 179     return 0;
 180 }
 181