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     if (!graph)
  38         return;
  39     for (; graph->filter_count > 0; graph->filter_count --)
  40         avfilter_free(graph->filters[graph->filter_count - 1]);
  41     av_freep(&graph->scale_sws_opts);
  42     av_freep(&graph->filters);
  43 }
  44
  45 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
  46 {
  47     AVFilterContext **filters = av_realloc(graph->filters,
  48                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
  49     if (!filters)
  50         return AVERROR(ENOMEM);
  51
  52     graph->filters = filters;
  53     graph->filters[graph->filter_count++] = filter;
  54
  55     return 0;
  56 }
  57
  58 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
  59                                  const char *name, const char *args, void *opaque,
  60                                  AVFilterGraph *graph_ctx)
  61 {
  62     int ret;
  63
  64     if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
  65         goto fail;
  66     if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
  67         goto fail;
  68     if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
  69         goto fail;
  70     return 0;
  71
  72 fail:
  73     if (*filt_ctx)
  74         avfilter_free(*filt_ctx);
  75     *filt_ctx = NULL;
  76     return ret;
  77 }
  78
  79 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  80 {
  81     AVFilterContext *filt;
  82     int i, j;
  83
  84     for (i = 0; i < graph->filter_count; i++) {
  85         filt = graph->filters[i];
  86
  87         for (j = 0; j < filt->input_count; j++) {
  88             if (!filt->inputs[j] || !filt->inputs[j]->src) {
  89                 av_log(log_ctx, AV_LOG_ERROR,
  90                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
  91                        filt->input_pads[j].name, filt->name, filt->filter->name);
  92                 return -1;
  93             }
  94         }
  95
  96         for (j = 0; j < filt->output_count; j++) {
  97             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
  98                 av_log(log_ctx, AV_LOG_ERROR,
  99                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
 100                        filt->output_pads[j].name, filt->name, filt->filter->name);
 101                 return -1;
 102             }
 103         }
 104     }
 105
 106     return 0;
 107 }
 108
 109 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
 110 {
 111     AVFilterContext *filt;
 112     int i, ret;
 113
 114     for (i=0; i < graph->filter_count; i++) {
 115         filt = graph->filters[i];
 116
 117         if (!filt->output_count) {
 118             if ((ret = avfilter_config_links(filt)))
 119                 return ret;
 120         }
 121     }
 122
 123     return 0;
 124 }
 125
 126 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
 127 {
 128     int i;
 129
 130     for (i = 0; i < graph->filter_count; i++)
 131         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 132             return graph->filters[i];
 133
 134     return NULL;
 135 }
 136
 137 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 138 {
 139     int i, j, ret;
 140     int scaler_count = 0;
 141     char inst_name[30];
 142
 143     /* ask all the sub-filters for their supported media formats */
 144     for (i = 0; i < graph->filter_count; i++) {
 145         if (graph->filters[i]->filter->query_formats)
 146             graph->filters[i]->filter->query_formats(graph->filters[i]);
 147         else
 148             avfilter_default_query_formats(graph->filters[i]);
 149     }
 150
 151     /* go through and merge as many format lists as possible */
 152     for (i = 0; i < graph->filter_count; i++) {
 153         AVFilterContext *filter = graph->filters[i];
 154
 155         for (j = 0; j < filter->input_count; j++) {
 156             AVFilterLink *link = filter->inputs[j];
 157             if (link && link->in_formats != link->out_formats) {
 158                 if (!avfilter_merge_formats(link->in_formats,
 159                                             link->out_formats)) {
 160                     AVFilterContext *scale;
 161                     char scale_args[256];
 162                     /* couldn't merge format lists. auto-insert scale filter */
 163                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 164                              scaler_count++);
 165                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
 166                     if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
 167                                                             inst_name, scale_args, NULL, graph)) < 0)
 168                         return ret;
 169                     if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
 170                         return ret;
 171
 172                     scale->filter->query_formats(scale);
 173                     if (((link = scale-> inputs[0]) &&
 174                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
 175                         ((link = scale->outputs[0]) &&
 176                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
 177                         av_log(log_ctx, AV_LOG_ERROR,
 178                                "Impossible to convert between the formats supported by the filter "
 179                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
 180                         return -1;
 181                     }
 182                 }
 183             }
 184         }
 185     }
 186
 187     return 0;
 188 }
 189
 190 static void pick_format(AVFilterLink *link)
 191 {
 192     if (!link || !link->in_formats)
 193         return;
 194
 195     link->in_formats->format_count = 1;
 196     link->format = link->in_formats->formats[0];
 197
 198     avfilter_formats_unref(&link->in_formats);
 199     avfilter_formats_unref(&link->out_formats);
 200 }
 201
 202 static void pick_formats(AVFilterGraph *graph)
 203 {
 204     int i, j;
 205
 206     for (i = 0; i < graph->filter_count; i++) {
 207         AVFilterContext *filter = graph->filters[i];
 208
 209         for (j = 0; j < filter->input_count; j++)
 210             pick_format(filter->inputs[j]);
 211         for (j = 0; j < filter->output_count; j++)
 212             pick_format(filter->outputs[j]);
 213     }
 214 }
 215
 216 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
 217 {
 218     /* find supported formats from sub-filters, and merge along links */
 219     if (query_formats(graph, log_ctx))
 220         return -1;
 221
 222     /* Once everything is merged, it's possible that we'll still have
 223      * multiple valid media format choices. We pick the first one. */
 224     pick_formats(graph);
 225
 226     return 0;
 227 }
 228
 229 int avfilter_graph_config(AVFilterGraph *graphctx, AVClass *log_ctx)
 230 {
 231     int ret;
 232
 233     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
 234         return ret;
 235     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
 236         return ret;
 237     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
 238         return ret;
 239
 240     return 0;
 241 }