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 AVFilterGraph *avfilter_graph_alloc(void)
  30 {
  31     return av_mallocz(sizeof(AVFilterGraph));
  32 }
  33
  34 void avfilter_graph_free(AVFilterGraph *graph)
  35 {
  36     for(; graph->filter_count > 0; graph->filter_count --)
  37         avfilter_destroy(graph->filters[graph->filter_count - 1]);
  38     av_freep(&graph->scale_sws_opts);
  39     av_freep(&graph->filters);
  40 }
  41
  42 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
  43 {
  44     AVFilterContext **filters = av_realloc(graph->filters,
  45                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
  46     if (!filters)
  47         return AVERROR(ENOMEM);
  48
  49     graph->filters = filters;
  50     graph->filters[graph->filter_count++] = filter;
  51
  52     return 0;
  53 }
  54
  55 int avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  56 {
  57     AVFilterContext *filt;
  58     int i, j;
  59
  60     for (i=0; i < graph->filter_count; i++) {
  61         filt = graph->filters[i];
  62
  63         for (j = 0; j < filt->input_count; j++) {
  64             if (!filt->inputs[j] || !filt->inputs[j]->src) {
  65                 av_log(log_ctx, AV_LOG_ERROR,
  66                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
  67                        filt->input_pads[j].name, filt->name, filt->filter->name);
  68                 return -1;
  69             }
  70         }
  71
  72         for (j = 0; j < filt->output_count; j++) {
  73             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
  74                 av_log(log_ctx, AV_LOG_ERROR,
  75                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
  76                        filt->output_pads[j].name, filt->name, filt->filter->name);
  77                 return -1;
  78             }
  79         }
  80     }
  81
  82     return 0;
  83 }
  84
  85 int avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
  86 {
  87     AVFilterContext *filt;
  88     int i, ret;
  89
  90     for (i=0; i < graph->filter_count; i++) {
  91         filt = graph->filters[i];
  92
  93         if (!filt->output_count) {
  94             if ((ret = avfilter_config_links(filt)))
  95                 return ret;
  96         }
  97     }
  98
  99     return 0;
 100 }
 101
 102 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
 103 {
 104     int i;
 105
 106     for(i = 0; i < graph->filter_count; i ++)
 107         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 108             return graph->filters[i];
 109
 110     return NULL;
 111 }
 112
 113 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 114 {
 115     int i, j;
 116     int scaler_count = 0;
 117     char inst_name[30];
 118
 119     /* ask all the sub-filters for their supported media formats */
 120     for(i = 0; i < graph->filter_count; i ++) {
 121         if(graph->filters[i]->filter->query_formats)
 122             graph->filters[i]->filter->query_formats(graph->filters[i]);
 123         else
 124             avfilter_default_query_formats(graph->filters[i]);
 125     }
 126
 127     /* go through and merge as many format lists as possible */
 128     for(i = 0; i < graph->filter_count; i ++) {
 129         AVFilterContext *filter = graph->filters[i];
 130
 131         for(j = 0; j < filter->input_count; j ++) {
 132             AVFilterLink *link = filter->inputs[j];
 133             if(link && link->in_formats != link->out_formats) {
 134                 if(!avfilter_merge_formats(link->in_formats,
 135                                            link->out_formats)) {
 136                     AVFilterContext *scale;
 137                     char scale_args[256];
 138                     /* couldn't merge format lists. auto-insert scale filter */
 139                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 140                              scaler_count++);
 141                     avfilter_open(&scale, avfilter_get_by_name("scale"), inst_name);
 142
 143                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
 144                     if(!scale || scale->filter->init(scale, scale_args, NULL) ||
 145                                  avfilter_insert_filter(link, scale, 0, 0)) {
 146                         avfilter_destroy(scale);
 147                         return -1;
 148                     }
 149
 150                     if (avfilter_graph_add_filter(graph, scale) < 0)
 151                         return -1;
 152
 153                     scale->filter->query_formats(scale);
 154                     if (((link = scale-> inputs[0]) &&
 155                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
 156                         ((link = scale->outputs[0]) &&
 157                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
 158                         av_log(log_ctx, AV_LOG_ERROR,
 159                                "Impossible to convert between the formats supported by the filter "
 160                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
 161                         return -1;
 162                     }
 163                 }
 164             }
 165         }
 166     }
 167
 168     return 0;
 169 }
 170
 171 static void pick_format(AVFilterLink *link)
 172 {
 173     if(!link || !link->in_formats)
 174         return;
 175
 176     link->in_formats->format_count = 1;
 177     link->format = link->in_formats->formats[0];
 178
 179     avfilter_formats_unref(&link->in_formats);
 180     avfilter_formats_unref(&link->out_formats);
 181 }
 182
 183 static void pick_formats(AVFilterGraph *graph)
 184 {
 185     int i, j;
 186
 187     for(i = 0; i < graph->filter_count; i ++) {
 188         AVFilterContext *filter = graph->filters[i];
 189
 190         for(j = 0; j < filter->input_count; j ++)
 191             pick_format(filter->inputs[j]);
 192         for(j = 0; j < filter->output_count; j ++)
 193             pick_format(filter->outputs[j]);
 194     }
 195 }
 196
 197 int avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
 198 {
 199     /* find supported formats from sub-filters, and merge along links */
 200     if(query_formats(graph, log_ctx))
 201         return -1;
 202
 203     /* Once everything is merged, it's possible that we'll still have
 204      * multiple valid media format choices. We pick the first one. */
 205     pick_formats(graph);
 206
 207     return 0;
 208 }
 209
 210 int avfilter_graph_config(AVFilterGraph *graphctx, AVClass *log_ctx)
 211 {
 212     int ret;
 213
 214     if ((ret = avfilter_graph_check_validity(graphctx, log_ctx)))
 215         return ret;
 216     if ((ret = avfilter_graph_config_formats(graphctx, log_ctx)))
 217         return ret;
 218     if ((ret = avfilter_graph_config_links(graphctx, log_ctx)))
 219         return ret;
 220
 221     return 0;
 222 }