libavfilter/avfiltergraph.c

   1 /*
   2  * filter graphs
   3  * copyright (c) 2007 Bobby Bingham
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "avfilter.h"
  23 #include "avfiltergraph.h"
  24
  25 typedef struct AVFilterGraph {
  26     unsigned filter_count;
  27     AVFilterContext **filters;
  28
  29     /** fake filters to handle links to internal filters */
  30     AVFilterContext *link_filter_in;
  31     AVFilterContext *link_filter_out;
  32 } GraphContext;
  33
  34 typedef struct {
  35     AVFilterContext *graph;
  36 } GraphLinkContext;
  37
  38 static int link_init(AVFilterContext *ctx, const char *args, void *opaque)
  39 {
  40     GraphLinkContext *linkctx = ctx->priv;
  41     linkctx->graph = opaque;
  42     return !opaque;
  43 }
  44
  45 /**
  46  * Given the link between the dummy filter and an internal filter whose input
  47  * is being exported outside the graph, this returns the externally visible
  48  * link.
  49  */
  50 static inline AVFilterLink *get_extern_input_link(AVFilterLink *link)
  51 {
  52     GraphLinkContext *lctx = link->src->priv;
  53     return lctx->graph->inputs[link->srcpad];
  54 }
  55
  56 /**
  57  * Given the link between the dummy filter and an internal filter whose output
  58  * is being exported outside the graph, this returns the externally visible
  59  * link.
  60  */
  61 static inline AVFilterLink *get_extern_output_link(AVFilterLink *link)
  62 {
  63     GraphLinkContext *lctx = link->dst->priv;
  64     return lctx->graph->outputs[link->dstpad];
  65 }
  66
  67
  68 /** dummy filter used to help export filters pads outside the graph */
  69 static AVFilter vf_graph_dummy =
  70 {
  71     .name      = "graph_dummy",
  72
  73     .priv_size = sizeof(GraphLinkContext),
  74
  75     .init      = link_init,
  76
  77     .inputs    = (AVFilterPad[]) {{ .name = NULL, }},
  78     .outputs   = (AVFilterPad[]) {{ .name = NULL, }},
  79 };
  80
  81 static void uninit(AVFilterContext *ctx)
  82 {
  83     GraphContext *graph = ctx->priv;
  84
  85     if(graph->link_filter_in) {
  86         avfilter_destroy(graph->link_filter_in);
  87         graph->link_filter_in = NULL;
  88     }
  89     if(graph->link_filter_out) {
  90         avfilter_destroy(graph->link_filter_out);
  91         graph->link_filter_out = NULL;
  92     }
  93     for(; graph->filter_count > 0; graph->filter_count --)
  94         avfilter_destroy(graph->filters[graph->filter_count - 1]);
  95     av_freep(&graph->filters);
  96 }
  97
  98 /* TODO: insert in sorted order */
  99 void avfilter_graph_add_filter(AVFilterContext *graphctx, AVFilterContext *filter)
 100 {
 101     GraphContext *graph = graphctx->priv;
 102
 103     graph->filters = av_realloc(graph->filters,
 104                                 sizeof(AVFilterContext*) * ++graph->filter_count);
 105     graph->filters[graph->filter_count - 1] = filter;
 106 }
 107
 108 /* search intelligently, once we insert in order */
 109 AVFilterContext *avfilter_graph_get_filter(AVFilterContext *ctx, char *name)
 110 {
 111     GraphContext *graph = ctx->priv;
 112     int i;
 113
 114     if(!name)
 115         return NULL;
 116
 117     for(i = 0; i < graph->filter_count; i ++)
 118         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 119             return graph->filters[i];
 120
 121     return NULL;
 122 }
 123
 124 static int query_formats(AVFilterContext *graphctx)
 125 {
 126     GraphContext *graph = graphctx->priv;
 127     AVFilterContext *linkfiltin  = graph->link_filter_in;
 128     AVFilterContext *linkfiltout = graph->link_filter_out;
 129     int i, j;
 130
 131     /* ask all the sub-filters for their supported colorspaces */
 132     for(i = 0; i < graph->filter_count; i ++) {
 133         if(graph->filters[i]->filter->query_formats)
 134             graph->filters[i]->filter->query_formats(graph->filters[i]);
 135         else
 136             avfilter_default_query_formats(graph->filters[i]);
 137     }
 138
 139     /* use these formats on our exported links */
 140     for(i = 0; i < linkfiltout->input_count; i ++) {
 141         avfilter_formats_ref( linkfiltout->inputs[i]->in_formats,
 142                              &linkfiltout->inputs[i]->out_formats);
 143
 144         if(graphctx->outputs[i])
 145             avfilter_formats_ref(linkfiltout->inputs[i]->in_formats,
 146                                  &graphctx->outputs[i]->in_formats);
 147     }
 148     for(i = 0; i < linkfiltin->output_count; i ++) {
 149         avfilter_formats_ref( linkfiltin->outputs[i]->out_formats,
 150                              &linkfiltin->outputs[i]->in_formats);
 151
 152         if(graphctx->inputs[i])
 153             avfilter_formats_ref(linkfiltin->outputs[i]->out_formats,
 154                                  &graphctx-> inputs[i]->out_formats);
 155     }
 156
 157     /* go through and merge as many format lists as possible */
 158     for(i = 0; i < graph->filter_count; i ++) {
 159         AVFilterContext *filter = graph->filters[i];
 160
 161         for(j = 0; j < filter->input_count; j ++) {
 162             AVFilterLink *link;
 163             if(!(link = filter->inputs[j]))
 164                 continue;
 165             if(link->in_formats != link->out_formats) {
 166                 if(!avfilter_merge_formats(link->in_formats,
 167                                            link->out_formats)) {
 168                     /* couldn't merge format lists. auto-insert scale filter */
 169                     AVFilterContext *scale;
 170
 171                     if(!(scale =
 172                          avfilter_open(avfilter_get_by_name("scale"), NULL)))
 173                         return -1;
 174                     if(scale->filter->init(scale, NULL, NULL) ||
 175                        avfilter_insert_filter(link, scale, 0, 0)) {
 176                         avfilter_destroy(scale);
 177                         return -1;
 178                     }
 179
 180                     avfilter_graph_add_filter(graphctx, scale);
 181                     scale->filter->query_formats(scale);
 182                     if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
 183                                               scale-> inputs[0]->out_formats) ||
 184                        !avfilter_merge_formats(scale->outputs[0]->in_formats,
 185                                               scale->outputs[0]->out_formats))
 186                         return -1;
 187                 }
 188             }
 189         }
 190     }
 191
 192     return 0;
 193 }
 194
 195 static void pick_format(AVFilterLink *link)
 196 {
 197     if(!link || !link->in_formats)
 198         return;
 199
 200     link->in_formats->format_count = 1;
 201     link->format = link->in_formats->formats[0];
 202
 203     avfilter_formats_unref(&link->in_formats);
 204     avfilter_formats_unref(&link->out_formats);
 205 }
 206
 207 static void pick_formats(GraphContext *graph)
 208 {
 209     int i, j;
 210
 211     for(i = 0; i < graph->filter_count; i ++) {
 212         AVFilterContext *filter = graph->filters[i];
 213
 214         if(filter->filter == &avfilter_vf_graph)
 215             pick_formats(filter->priv);
 216
 217         for(j = 0; j < filter->input_count; j ++)
 218             pick_format(filter->inputs[j]);
 219         for(j = 0; j < filter->output_count; j ++)
 220             pick_format(filter->outputs[j]);
 221     }
 222 }
 223
 224 int avfilter_graph_config_formats(AVFilterContext *graphctx)
 225 {
 226     GraphContext *graph = graphctx->priv;
 227
 228     /* find supported formats from sub-filters, and merge along links */
 229     if(query_formats(graphctx))
 230         return -1;
 231
 232     /* Once everything is merged, it's possible that we'll still have
 233      * multiple valid colorspace choices. We pick the first one. */
 234     pick_formats(graph);
 235
 236     return 0;
 237 }
 238
 239 static int graph_load_from_desc2(AVFilterContext *ctx, AVFilterGraphDesc *desc)
 240 {
 241     AVFilterGraphDescFilter *curfilt;
 242     AVFilterGraphDescLink   *curlink;
 243     AVFilterContext *filt, *filtb;
 244
 245     AVFilter *filterdef;
 246     char tmp[20];
 247
 248     /* create all filters */
 249     for(curfilt = desc->filters; curfilt; curfilt = curfilt->next) {
 250         snprintf(tmp, 20, "%d", curfilt->index);
 251         if(!(filterdef = avfilter_get_by_name(curfilt->filter)) ||
 252            !(filt = avfilter_open(filterdef, tmp))) {
 253             av_log(ctx, AV_LOG_ERROR,
 254                "error creating filter '%s'\n", curfilt->filter);
 255             goto fail;
 256         }
 257         avfilter_graph_add_filter(ctx, filt);
 258         if(avfilter_init_filter(filt, curfilt->args, NULL)) {
 259             av_log(ctx, AV_LOG_ERROR,
 260                 "error initializing filter '%s'\n", curfilt->filter);
 261             goto fail;
 262         }
 263     }
 264
 265     /* create all links */
 266     for(curlink = desc->links; curlink; curlink = curlink->next) {
 267         snprintf(tmp, 20, "%d", curlink->src);
 268         if(!(filt = avfilter_graph_get_filter(ctx, tmp))) {
 269             av_log(ctx, AV_LOG_ERROR, "link source does not exist in graph\n");
 270             goto fail;
 271         }
 272         snprintf(tmp, 20, "%d", curlink->dst);
 273         if(!(filtb = avfilter_graph_get_filter(ctx, tmp))) {
 274             av_log(ctx, AV_LOG_ERROR, "link destination does not exist in graph\n");
 275             goto fail;
 276         }
 277         if(avfilter_link(filt, curlink->srcpad, filtb, curlink->dstpad)) {
 278             av_log(ctx, AV_LOG_ERROR, "cannot create link between source and destination filters\n");
 279             goto fail;
 280         }
 281     }
 282
 283     return 0;
 284
 285 fail:
 286     uninit(ctx);
 287     return -1;
 288 }
 289
 290 int graph_load_from_desc3(AVFilterContext *ctx, AVFilterGraphDesc *desc, AVFilterContext *in, int inpad, AVFilterContext *out, int outpad)
 291 {
 292     AVFilterGraphDescExport *curpad;
 293     char tmp[20];
 294     AVFilterContext *filt;
 295
 296     if (graph_load_from_desc2(ctx, desc) < 0)
 297         goto fail;
 298
 299     /* export all input pads */
 300     for(curpad = desc->inputs; curpad; curpad = curpad->next) {
 301         snprintf(tmp, 20, "%d", curpad->filter);
 302         if(!(filt = avfilter_graph_get_filter(ctx, tmp))) {
 303             av_log(ctx, AV_LOG_ERROR, "filter owning exported pad does not exist\n");
 304             goto fail;
 305         }
 306         if(avfilter_link(in, inpad, filt, curpad->pad)) {
 307             av_log(ctx, AV_LOG_ERROR, "cannot create link between source and destination filters\n");
 308             goto fail;
 309         }
 310     }
 311
 312     /* export all output pads */
 313     for(curpad = desc->outputs; curpad; curpad = curpad->next) {
 314         snprintf(tmp, 20, "%d", curpad->filter);
 315         if(!(filt = avfilter_graph_get_filter(ctx, tmp))) {
 316             av_log(ctx, AV_LOG_ERROR, "filter owning exported pad does not exist\n");
 317             goto fail;
 318         }
 319
 320         if(avfilter_link(filt, curpad->pad, out, outpad)) {
 321             av_log(ctx, AV_LOG_ERROR, "cannot create link between source and destination filters\n");
 322             goto fail;
 323         }
 324     }
 325
 326     return 0;
 327
 328 fail:
 329     uninit(ctx);
 330     return -1;
 331 }
 332
 333 static int init(AVFilterContext *ctx, const char *args, void *opaque)
 334 {
 335     GraphContext *gctx = ctx->priv;
 336
 337     if(!(gctx->link_filter_in = avfilter_open(&vf_graph_dummy, NULL)))
 338         return -1;
 339     if(avfilter_init_filter(gctx->link_filter_in, NULL, ctx))
 340         goto fail;
 341     if(!(gctx->link_filter_out = avfilter_open(&vf_graph_dummy, NULL)))
 342         goto fail;
 343     if(avfilter_init_filter(gctx->link_filter_out, NULL, ctx))
 344         goto fail;
 345
 346     return 0;
 347
 348 fail:
 349     avfilter_destroy(gctx->link_filter_in);
 350     if(gctx->link_filter_out)
 351         avfilter_destroy(gctx->link_filter_out);
 352     return -1;
 353 }
 354
 355 AVFilter avfilter_vf_graph =
 356 {
 357     .name      = "graph",
 358
 359     .priv_size = sizeof(GraphContext),
 360
 361     .init      = init,
 362     .uninit    = uninit,
 363
 364     .query_formats = query_formats,
 365
 366     .inputs    = (AVFilterPad[]) {{ .name = NULL, }},
 367     .outputs   = (AVFilterPad[]) {{ .name = NULL, }},
 368 };
 369