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 Libav.
   7  *
   8  * Libav 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  * Libav 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 Libav; 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     av_freep(graph);
  44 }
  45
  46 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
  47 {
  48     AVFilterContext **filters = av_realloc(graph->filters,
  49                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
  50     if (!filters)
  51         return AVERROR(ENOMEM);
  52
  53     graph->filters = filters;
  54     graph->filters[graph->filter_count++] = filter;
  55
  56     return 0;
  57 }
  58
  59 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
  60                                  const char *name, const char *args, void *opaque,
  61                                  AVFilterGraph *graph_ctx)
  62 {
  63     int ret;
  64
  65     if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
  66         goto fail;
  67     if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
  68         goto fail;
  69     if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
  70         goto fail;
  71     return 0;
  72
  73 fail:
  74     if (*filt_ctx)
  75         avfilter_free(*filt_ctx);
  76     *filt_ctx = NULL;
  77     return ret;
  78 }
  79
  80 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
  81 {
  82     AVFilterContext *filt;
  83     int i, j;
  84
  85     for (i = 0; i < graph->filter_count; i++) {
  86         filt = graph->filters[i];
  87
  88         for (j = 0; j < filt->input_count; j++) {
  89             if (!filt->inputs[j] || !filt->inputs[j]->src) {
  90                 av_log(log_ctx, AV_LOG_ERROR,
  91                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
  92                        filt->input_pads[j].name, filt->name, filt->filter->name);
  93                 return -1;
  94             }
  95         }
  96
  97         for (j = 0; j < filt->output_count; j++) {
  98             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
  99                 av_log(log_ctx, AV_LOG_ERROR,
 100                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
 101                        filt->output_pads[j].name, filt->name, filt->filter->name);
 102                 return -1;
 103             }
 104         }
 105     }
 106
 107     return 0;
 108 }
 109
 110 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
 111 {
 112     AVFilterContext *filt;
 113     int i, ret;
 114
 115     for (i=0; i < graph->filter_count; i++) {
 116         filt = graph->filters[i];
 117
 118         if (!filt->output_count) {
 119             if ((ret = avfilter_config_links(filt)))
 120                 return ret;
 121         }
 122     }
 123
 124     return 0;
 125 }
 126
 127 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
 128 {
 129     int i;
 130
 131     for (i = 0; i < graph->filter_count; i++)
 132         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 133             return graph->filters[i];
 134
 135     return NULL;
 136 }
 137
 138 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 139 {
 140     int i, j, ret;
 141     int scaler_count = 0;
 142     char inst_name[30];
 143
 144     /* ask all the sub-filters for their supported media formats */
 145     for (i = 0; i < graph->filter_count; i++) {
 146         if (graph->filters[i]->filter->query_formats)
 147             graph->filters[i]->filter->query_formats(graph->filters[i]);
 148         else
 149             avfilter_default_query_formats(graph->filters[i]);
 150     }
 151
 152     /* go through and merge as many format lists as possible */
 153     for (i = 0; i < graph->filter_count; i++) {
 154         AVFilterContext *filter = graph->filters[i];
 155
 156         for (j = 0; j < filter->input_count; j++) {
 157             AVFilterLink *link = filter->inputs[j];
 158             if (link && link->in_formats != link->out_formats) {
 159                 if (!avfilter_merge_formats(link->in_formats,
 160                                             link->out_formats)) {
 161                     AVFilterContext *scale;
 162                     char scale_args[256];
 163                     /* couldn't merge format lists. auto-insert scale filter */
 164                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 165                              scaler_count++);
 166                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
 167                     if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
 168                                                             inst_name, scale_args, NULL, graph)) < 0)
 169                         return ret;
 170                     if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
 171                         return ret;
 172
 173                     scale->filter->query_formats(scale);
 174                     if (((link = scale-> inputs[0]) &&
 175                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
 176                         ((link = scale->outputs[0]) &&
 177                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
 178                         av_log(log_ctx, AV_LOG_ERROR,
 179                                "Impossible to convert between the formats supported by the filter "
 180                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
 181                         return -1;
 182                     }
 183                 }
 184             }
 185         }
 186     }
 187
 188     return 0;
 189 }
 190
 191 static void pick_format(AVFilterLink *link)
 192 {
 193     if (!link || !link->in_formats)
 194         return;
 195
 196     link->in_formats->format_count = 1;
 197     link->format = link->in_formats->formats[0];
 198
 199     avfilter_formats_unref(&link->in_formats);
 200     avfilter_formats_unref(&link->out_formats);
 201 }
 202
 203 static void pick_formats(AVFilterGraph *graph)
 204 {
 205     int i, j;
 206
 207     for (i = 0; i < graph->filter_count; i++) {
 208         AVFilterContext *filter = graph->filters[i];
 209
 210         for (j = 0; j < filter->input_count; j++)
 211             pick_format(filter->inputs[j]);
 212         for (j = 0; j < filter->output_count; j++)
 213             pick_format(filter->outputs[j]);
 214     }
 215 }
 216
 217 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
 218 {
 219     /* find supported formats from sub-filters, and merge along links */
 220     if (query_formats(graph, log_ctx))
 221         return -1;
 222
 223     /* Once everything is merged, it's possible that we'll still have
 224      * multiple valid media format choices. We pick the first one. */
 225     pick_formats(graph);
 226
 227     return 0;
 228 }
 229
 230 int avfilter_graph_config(AVFilterGraph *graphctx, AVClass *log_ctx)
 231 {
 232     int ret;
 233
 234     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
 235         return ret;
 236     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
 237         return ret;
 238     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
 239         return ret;
 240
 241     return 0;
 242 }