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_graph_destroy(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->scale_sws_opts);
  34     av_freep(&graph->filters);
  35 }
  36
  37 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
  38 {
  39     graph->filters = av_realloc(graph->filters,
  40                                 sizeof(AVFilterContext*) * ++graph->filter_count);
  41
  42     if (!graph->filters)
  43         return -1;
  44
  45     graph->filters[graph->filter_count - 1] = filter;
  46
  47     return 0;
  48 }
  49
  50 int avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  51 {
  52     AVFilterContext *filt;
  53     int i, j;
  54
  55     for (i=0; i < graph->filter_count; i++) {
  56         filt = graph->filters[i];
  57
  58         for (j = 0; j < filt->input_count; j++) {
  59             if (!filt->inputs[j] || !filt->inputs[j]->src) {
  60                 av_log(log_ctx, AV_LOG_ERROR,
  61                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
  62                        filt->input_pads[j].name, filt->name, filt->filter->name);
  63                 return -1;
  64             }
  65         }
  66
  67         for (j = 0; j < filt->output_count; j++) {
  68             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
  69                 av_log(log_ctx, AV_LOG_ERROR,
  70                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
  71                        filt->output_pads[j].name, filt->name, filt->filter->name);
  72                 return -1;
  73             }
  74         }
  75     }
  76
  77     return 0;
  78 }
  79
  80 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
  81 {
  82     int i;
  83
  84     for(i = 0; i < graph->filter_count; i ++)
  85         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
  86             return graph->filters[i];
  87
  88     return NULL;
  89 }
  90
  91 static int query_formats(AVFilterGraph *graph)
  92 {
  93     int i, j;
  94     int scaler_count = 0;
  95     char inst_name[30];
  96
  97     /* ask all the sub-filters for their supported colorspaces */
  98     for(i = 0; i < graph->filter_count; i ++) {
  99         if(graph->filters[i]->filter->query_formats)
 100             graph->filters[i]->filter->query_formats(graph->filters[i]);
 101         else
 102             avfilter_default_query_formats(graph->filters[i]);
 103     }
 104
 105     /* go through and merge as many format lists as possible */
 106     for(i = 0; i < graph->filter_count; i ++) {
 107         AVFilterContext *filter = graph->filters[i];
 108
 109         for(j = 0; j < filter->input_count; j ++) {
 110             AVFilterLink *link = filter->inputs[j];
 111             if(link && link->in_formats != link->out_formats) {
 112                 if(!avfilter_merge_formats(link->in_formats,
 113                                            link->out_formats)) {
 114                     AVFilterContext *scale;
 115                     char scale_args[256];
 116                     /* couldn't merge format lists. auto-insert scale filter */
 117                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 118                              scaler_count);
 119                     scale =
 120                         avfilter_open(avfilter_get_by_name("scale"),inst_name);
 121
 122                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
 123                     if(!scale || scale->filter->init(scale, scale_args, NULL) ||
 124                                  avfilter_insert_filter(link, scale, 0, 0)) {
 125                         avfilter_destroy(scale);
 126                         return -1;
 127                     }
 128
 129                     if (avfilter_graph_add_filter(graph, scale) < 0)
 130                         return -1;
 131
 132                     scale->filter->query_formats(scale);
 133                     if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
 134                                                scale-> inputs[0]->out_formats)||
 135                        !avfilter_merge_formats(scale->outputs[0]->in_formats,
 136                                                scale->outputs[0]->out_formats))
 137                         return -1;
 138                 }
 139             }
 140         }
 141     }
 142
 143     return 0;
 144 }
 145
 146 static void pick_format(AVFilterLink *link)
 147 {
 148     if(!link || !link->in_formats)
 149         return;
 150
 151     link->in_formats->format_count = 1;
 152     link->format = link->in_formats->formats[0];
 153
 154     avfilter_formats_unref(&link->in_formats);
 155     avfilter_formats_unref(&link->out_formats);
 156 }
 157
 158 static void pick_formats(AVFilterGraph *graph)
 159 {
 160     int i, j;
 161
 162     for(i = 0; i < graph->filter_count; i ++) {
 163         AVFilterContext *filter = graph->filters[i];
 164
 165         for(j = 0; j < filter->input_count; j ++)
 166             pick_format(filter->inputs[j]);
 167         for(j = 0; j < filter->output_count; j ++)
 168             pick_format(filter->outputs[j]);
 169     }
 170 }
 171
 172 int avfilter_graph_config_formats(AVFilterGraph *graph)
 173 {
 174     /* find supported formats from sub-filters, and merge along links */
 175     if(query_formats(graph))
 176         return -1;
 177
 178     /* Once everything is merged, it's possible that we'll still have
 179      * multiple valid colorspace choices. We pick the first one. */
 180     pick_formats(graph);
 181
 182     return 0;
 183 }
 184