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 #include "internal.h"
  29
  30 AVFilterGraph *avfilter_graph_alloc(void)
  31 {
  32     return av_mallocz(sizeof(AVFilterGraph));
  33 }
  34
  35 void avfilter_graph_free(AVFilterGraph *graph)
  36 {
  37     for(; graph->filter_count > 0; graph->filter_count --)
  38         avfilter_free(graph->filters[graph->filter_count - 1]);
  39     av_freep(&graph->scale_sws_opts);
  40     av_freep(&graph->filters);
  41 }
  42
  43 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
  44 {
  45     AVFilterContext **filters = av_realloc(graph->filters,
  46                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
  47     if (!filters)
  48         return AVERROR(ENOMEM);
  49
  50     graph->filters = filters;
  51     graph->filters[graph->filter_count++] = filter;
  52
  53     return 0;
  54 }
  55
  56 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  57 {
  58     AVFilterContext *filt;
  59     int i, j;
  60
  61     for (i=0; i < graph->filter_count; i++) {
  62         filt = graph->filters[i];
  63
  64         for (j = 0; j < filt->input_count; j++) {
  65             if (!filt->inputs[j] || !filt->inputs[j]->src) {
  66                 av_log(log_ctx, AV_LOG_ERROR,
  67                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
  68                        filt->input_pads[j].name, filt->name, filt->filter->name);
  69                 return -1;
  70             }
  71         }
  72
  73         for (j = 0; j < filt->output_count; j++) {
  74             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
  75                 av_log(log_ctx, AV_LOG_ERROR,
  76                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
  77                        filt->output_pads[j].name, filt->name, filt->filter->name);
  78                 return -1;
  79             }
  80         }
  81     }
  82
  83     return 0;
  84 }
  85
  86 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
  87 {
  88     AVFilterContext *filt;
  89     int i, ret;
  90
  91     for (i=0; i < graph->filter_count; i++) {
  92         filt = graph->filters[i];
  93
  94         if (!filt->output_count) {
  95             if ((ret = avfilter_config_links(filt)))
  96                 return ret;
  97         }
  98     }
  99
 100     return 0;
 101 }
 102
 103 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
 104 {
 105     int i;
 106
 107     for(i = 0; i < graph->filter_count; i ++)
 108         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 109             return graph->filters[i];
 110
 111     return NULL;
 112 }
 113
 114 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 115 {
 116     int i, j;
 117     int scaler_count = 0;
 118     char inst_name[30];
 119
 120     /* ask all the sub-filters for their supported media formats */
 121     for(i = 0; i < graph->filter_count; i ++) {
 122         if(graph->filters[i]->filter->query_formats)
 123             graph->filters[i]->filter->query_formats(graph->filters[i]);
 124         else
 125             avfilter_default_query_formats(graph->filters[i]);
 126     }
 127
 128     /* go through and merge as many format lists as possible */
 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             AVFilterLink *link = filter->inputs[j];
 134             if(link && link->in_formats != link->out_formats) {
 135                 if(!avfilter_merge_formats(link->in_formats,
 136                                            link->out_formats)) {
 137                     AVFilterContext *scale;
 138                     char scale_args[256];
 139                     /* couldn't merge format lists. auto-insert scale filter */
 140                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 141                              scaler_count++);
 142                     avfilter_open(&scale, avfilter_get_by_name("scale"), inst_name);
 143
 144                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
 145                     if(!scale || scale->filter->init(scale, scale_args, NULL) ||
 146                                  avfilter_insert_filter(link, scale, 0, 0)) {
 147                         avfilter_free(scale);
 148                         return -1;
 149                     }
 150
 151                     if (avfilter_graph_add_filter(graph, scale) < 0)
 152                         return -1;
 153
 154                     scale->filter->query_formats(scale);
 155                     if (((link = scale-> inputs[0]) &&
 156                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
 157                         ((link = scale->outputs[0]) &&
 158                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
 159                         av_log(log_ctx, AV_LOG_ERROR,
 160                                "Impossible to convert between the formats supported by the filter "
 161                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
 162                         return -1;
 163                     }
 164                 }
 165             }
 166         }
 167     }
 168
 169     return 0;
 170 }
 171
 172 static void pick_format(AVFilterLink *link)
 173 {
 174     if(!link || !link->in_formats)
 175         return;
 176
 177     link->in_formats->format_count = 1;
 178     link->format = link->in_formats->formats[0];
 179
 180     avfilter_formats_unref(&link->in_formats);
 181     avfilter_formats_unref(&link->out_formats);
 182 }
 183
 184 static void pick_formats(AVFilterGraph *graph)
 185 {
 186     int i, j;
 187
 188     for(i = 0; i < graph->filter_count; i ++) {
 189         AVFilterContext *filter = graph->filters[i];
 190
 191         for(j = 0; j < filter->input_count; j ++)
 192             pick_format(filter->inputs[j]);
 193         for(j = 0; j < filter->output_count; j ++)
 194             pick_format(filter->outputs[j]);
 195     }
 196 }
 197
 198 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
 199 {
 200     /* find supported formats from sub-filters, and merge along links */
 201     if(query_formats(graph, log_ctx))
 202         return -1;
 203
 204     /* Once everything is merged, it's possible that we'll still have
 205      * multiple valid media format choices. We pick the first one. */
 206     pick_formats(graph);
 207
 208     return 0;
 209 }
 210
 211 int avfilter_graph_config(AVFilterGraph *graphctx, AVClass *log_ctx)
 212 {
 213     int ret;
 214
 215     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
 216         return ret;
 217     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
 218         return ret;
 219     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
 220         return ret;
 221
 222     return 0;
 223 }