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 avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
  57                                  const char *name, const char *args, void *opaque,
  58                                  AVFilterGraph *graph_ctx)
  59 {
  60     int ret;
  61
  62     if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
  63         goto fail;
  64     if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
  65         goto fail;
  66     if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
  67         goto fail;
  68     return 0;
  69
  70 fail:
  71     if (*filt_ctx)
  72         avfilter_free(*filt_ctx);
  73     *filt_ctx = NULL;
  74     return ret;
  75 }
  76
  77 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  78 {
  79     AVFilterContext *filt;
  80     int i, j;
  81
  82     for (i=0; i < graph->filter_count; i++) {
  83         filt = graph->filters[i];
  84
  85         for (j = 0; j < filt->input_count; j++) {
  86             if (!filt->inputs[j] || !filt->inputs[j]->src) {
  87                 av_log(log_ctx, AV_LOG_ERROR,
  88                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
  89                        filt->input_pads[j].name, filt->name, filt->filter->name);
  90                 return -1;
  91             }
  92         }
  93
  94         for (j = 0; j < filt->output_count; j++) {
  95             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
  96                 av_log(log_ctx, AV_LOG_ERROR,
  97                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
  98                        filt->output_pads[j].name, filt->name, filt->filter->name);
  99                 return -1;
 100             }
 101         }
 102     }
 103
 104     return 0;
 105 }
 106
 107 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
 108 {
 109     AVFilterContext *filt;
 110     int i, ret;
 111
 112     for (i=0; i < graph->filter_count; i++) {
 113         filt = graph->filters[i];
 114
 115         if (!filt->output_count) {
 116             if ((ret = avfilter_config_links(filt)))
 117                 return ret;
 118         }
 119     }
 120
 121     return 0;
 122 }
 123
 124 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
 125 {
 126     int i;
 127
 128     for(i = 0; i < graph->filter_count; i ++)
 129         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 130             return graph->filters[i];
 131
 132     return NULL;
 133 }
 134
 135 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 136 {
 137     int i, j, ret;
 138     int scaler_count = 0;
 139     char inst_name[30];
 140
 141     /* ask all the sub-filters for their supported media formats */
 142     for(i = 0; i < graph->filter_count; i ++) {
 143         if(graph->filters[i]->filter->query_formats)
 144             graph->filters[i]->filter->query_formats(graph->filters[i]);
 145         else
 146             avfilter_default_query_formats(graph->filters[i]);
 147     }
 148
 149     /* go through and merge as many format lists as possible */
 150     for(i = 0; i < graph->filter_count; i ++) {
 151         AVFilterContext *filter = graph->filters[i];
 152
 153         for(j = 0; j < filter->input_count; j ++) {
 154             AVFilterLink *link = filter->inputs[j];
 155             if(link && link->in_formats != link->out_formats) {
 156                 if(!avfilter_merge_formats(link->in_formats,
 157                                            link->out_formats)) {
 158                     AVFilterContext *scale;
 159                     char scale_args[256];
 160                     /* couldn't merge format lists. auto-insert scale filter */
 161                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 162                              scaler_count++);
 163                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
 164                     if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
 165                                                             inst_name, scale_args, NULL, graph)) < 0)
 166                         return ret;
 167                     if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
 168                         return ret;
 169
 170                     scale->filter->query_formats(scale);
 171                     if (((link = scale-> inputs[0]) &&
 172                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
 173                         ((link = scale->outputs[0]) &&
 174                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
 175                         av_log(log_ctx, AV_LOG_ERROR,
 176                                "Impossible to convert between the formats supported by the filter "
 177                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
 178                         return -1;
 179                     }
 180                 }
 181             }
 182         }
 183     }
 184
 185     return 0;
 186 }
 187
 188 static void pick_format(AVFilterLink *link)
 189 {
 190     if(!link || !link->in_formats)
 191         return;
 192
 193     link->in_formats->format_count = 1;
 194     link->format = link->in_formats->formats[0];
 195
 196     avfilter_formats_unref(&link->in_formats);
 197     avfilter_formats_unref(&link->out_formats);
 198 }
 199
 200 static void pick_formats(AVFilterGraph *graph)
 201 {
 202     int i, j;
 203
 204     for(i = 0; i < graph->filter_count; i ++) {
 205         AVFilterContext *filter = graph->filters[i];
 206
 207         for(j = 0; j < filter->input_count; j ++)
 208             pick_format(filter->inputs[j]);
 209         for(j = 0; j < filter->output_count; j ++)
 210             pick_format(filter->outputs[j]);
 211     }
 212 }
 213
 214 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
 215 {
 216     /* find supported formats from sub-filters, and merge along links */
 217     if(query_formats(graph, log_ctx))
 218         return -1;
 219
 220     /* Once everything is merged, it's possible that we'll still have
 221      * multiple valid media format choices. We pick the first one. */
 222     pick_formats(graph);
 223
 224     return 0;
 225 }
 226
 227 int avfilter_graph_config(AVFilterGraph *graphctx, AVClass *log_ctx)
 228 {
 229     int ret;
 230
 231     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
 232         return ret;
 233     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
 234         return ret;
 235     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
 236         return ret;
 237
 238     return 0;
 239 }