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 "config.h"
  24
  25 #include <string.h>
  26
  27 #include "libavutil/avassert.h"
  28 #include "libavutil/avstring.h"
  29 #include "libavutil/channel_layout.h"
  30 #include "libavutil/common.h"
  31 #include "libavutil/internal.h"
  32 #include "libavutil/log.h"
  33 #include "libavutil/opt.h"
  34
  35 #include "avfilter.h"
  36 #include "formats.h"
  37 #include "internal.h"
  38 #include "thread.h"
  39
  40 #define OFFSET(x) offsetof(AVFilterGraph, x)
  41 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
  42 static const AVOption filtergraph_options[] = {
  43     { "thread_type", "Allowed thread types", OFFSET(thread_type), AV_OPT_TYPE_FLAGS,
  44         { .i64 = AVFILTER_THREAD_SLICE }, 0, INT_MAX, FLAGS, "thread_type" },
  45         { "slice", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AVFILTER_THREAD_SLICE }, .flags = FLAGS, .unit = "thread_type" },
  46     { "threads",     "Maximum number of threads", OFFSET(nb_threads),
  47         AV_OPT_TYPE_INT,   { .i64 = 0 }, 0, INT_MAX, FLAGS },
  48     { NULL },
  49 };
  50
  51 static const AVClass filtergraph_class = {
  52     .class_name = "AVFilterGraph",
  53     .item_name  = av_default_item_name,
  54     .version    = LIBAVUTIL_VERSION_INT,
  55     .option     = filtergraph_options,
  56 };
  57
  58 #if !HAVE_THREADS
  59 void ff_graph_thread_free(AVFilterGraph *graph)
  60 {
  61 }
  62
  63 int ff_graph_thread_init(AVFilterGraph *graph)
  64 {
  65     graph->thread_type = 0;
  66     graph->nb_threads  = 1;
  67     return 0;
  68 }
  69 #endif
  70
  71 AVFilterGraph *avfilter_graph_alloc(void)
  72 {
  73     AVFilterGraph *ret = av_mallocz(sizeof(*ret));
  74     if (!ret)
  75         return NULL;
  76
  77     ret->internal = av_mallocz(sizeof(*ret->internal));
  78     if (!ret->internal) {
  79         av_freep(&ret);
  80         return NULL;
  81     }
  82
  83     ret->av_class = &filtergraph_class;
  84     av_opt_set_defaults(ret);
  85
  86     return ret;
  87 }
  88
  89 void ff_filter_graph_remove_filter(AVFilterGraph *graph, AVFilterContext *filter)
  90 {
  91     int i;
  92     for (i = 0; i < graph->nb_filters; i++) {
  93         if (graph->filters[i] == filter) {
  94             FFSWAP(AVFilterContext*, graph->filters[i],
  95                    graph->filters[graph->nb_filters - 1]);
  96             graph->nb_filters--;
  97             return;
  98         }
  99     }
 100 }
 101
 102 void avfilter_graph_free(AVFilterGraph **graph)
 103 {
 104     if (!*graph)
 105         return;
 106
 107     while ((*graph)->nb_filters)
 108         avfilter_free((*graph)->filters[0]);
 109
 110     ff_graph_thread_free(*graph);
 111
 112     av_freep(&(*graph)->scale_sws_opts);
 113     av_freep(&(*graph)->resample_lavr_opts);
 114     av_freep(&(*graph)->filters);
 115     av_freep(&(*graph)->internal);
 116     av_freep(graph);
 117 }
 118
 119 #if FF_API_AVFILTER_OPEN
 120 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
 121 {
 122     AVFilterContext **filters = av_realloc(graph->filters,
 123                                            sizeof(*filters) * (graph->nb_filters + 1));
 124     if (!filters)
 125         return AVERROR(ENOMEM);
 126
 127     graph->filters = filters;
 128     graph->filters[graph->nb_filters++] = filter;
 129
 130 #if FF_API_FOO_COUNT
 131 FF_DISABLE_DEPRECATION_WARNINGS
 132     graph->filter_count = graph->nb_filters;
 133 FF_ENABLE_DEPRECATION_WARNINGS
 134 #endif
 135
 136     filter->graph = graph;
 137
 138     return 0;
 139 }
 140 #endif
 141
 142 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
 143                                  const char *name, const char *args, void *opaque,
 144                                  AVFilterGraph *graph_ctx)
 145 {
 146     int ret;
 147
 148     *filt_ctx = avfilter_graph_alloc_filter(graph_ctx, filt, name);
 149     if (!*filt_ctx)
 150         return AVERROR(ENOMEM);
 151
 152     ret = avfilter_init_str(*filt_ctx, args);
 153     if (ret < 0)
 154         goto fail;
 155
 156     return 0;
 157
 158 fail:
 159     if (*filt_ctx)
 160         avfilter_free(*filt_ctx);
 161     *filt_ctx = NULL;
 162     return ret;
 163 }
 164
 165 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
 166                                              const AVFilter *filter,
 167                                              const char *name)
 168 {
 169     AVFilterContext **filters, *s;
 170
 171     if (graph->thread_type && !graph->internal->thread_execute) {
 172         if (graph->execute) {
 173             graph->internal->thread_execute = graph->execute;
 174         } else {
 175             int ret = ff_graph_thread_init(graph);
 176             if (ret < 0) {
 177                 av_log(graph, AV_LOG_ERROR, "Error initializing threading.\n");
 178                 return NULL;
 179             }
 180         }
 181     }
 182
 183     s = ff_filter_alloc(filter, name);
 184     if (!s)
 185         return NULL;
 186
 187     filters = av_realloc(graph->filters, sizeof(*filters) * (graph->nb_filters + 1));
 188     if (!filters) {
 189         avfilter_free(s);
 190         return NULL;
 191     }
 192
 193     graph->filters = filters;
 194     graph->filters[graph->nb_filters++] = s;
 195
 196 #if FF_API_FOO_COUNT
 197 FF_DISABLE_DEPRECATION_WARNINGS
 198     graph->filter_count = graph->nb_filters;
 199 FF_ENABLE_DEPRECATION_WARNINGS
 200 #endif
 201
 202     s->graph = graph;
 203
 204     return s;
 205 }
 206
 207 /**
 208  * Check for the validity of graph.
 209  *
 210  * A graph is considered valid if all its input and output pads are
 211  * connected.
 212  *
 213  * @return 0 in case of success, a negative value otherwise
 214  */
 215 static int graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
 216 {
 217     AVFilterContext *filt;
 218     int i, j;
 219
 220     for (i = 0; i < graph->nb_filters; i++) {
 221         filt = graph->filters[i];
 222
 223         for (j = 0; j < filt->nb_inputs; j++) {
 224             if (!filt->inputs[j] || !filt->inputs[j]->src) {
 225                 av_log(log_ctx, AV_LOG_ERROR,
 226                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
 227                        filt->input_pads[j].name, filt->name, filt->filter->name);
 228                 return AVERROR(EINVAL);
 229             }
 230         }
 231
 232         for (j = 0; j < filt->nb_outputs; j++) {
 233             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
 234                 av_log(log_ctx, AV_LOG_ERROR,
 235                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
 236                        filt->output_pads[j].name, filt->name, filt->filter->name);
 237                 return AVERROR(EINVAL);
 238             }
 239         }
 240     }
 241
 242     return 0;
 243 }
 244
 245 /**
 246  * Configure all the links of graphctx.
 247  *
 248  * @return 0 in case of success, a negative value otherwise
 249  */
 250 static int graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
 251 {
 252     AVFilterContext *filt;
 253     int i, ret;
 254
 255     for (i = 0; i < graph->nb_filters; i++) {
 256         filt = graph->filters[i];
 257
 258         if (!filt->nb_outputs) {
 259             if ((ret = avfilter_config_links(filt)))
 260                 return ret;
 261         }
 262     }
 263
 264     return 0;
 265 }
 266
 267 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
 268 {
 269     int i;
 270
 271     for (i = 0; i < graph->nb_filters; i++)
 272         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
 273             return graph->filters[i];
 274
 275     return NULL;
 276 }
 277
 278 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 279 {
 280     int i, j, ret;
 281     int scaler_count = 0, resampler_count = 0;
 282
 283     /* ask all the sub-filters for their supported media formats */
 284     for (i = 0; i < graph->nb_filters; i++) {
 285         if (graph->filters[i]->filter->query_formats)
 286             graph->filters[i]->filter->query_formats(graph->filters[i]);
 287         else
 288             ff_default_query_formats(graph->filters[i]);
 289     }
 290
 291     /* go through and merge as many format lists as possible */
 292     for (i = 0; i < graph->nb_filters; i++) {
 293         AVFilterContext *filter = graph->filters[i];
 294
 295         for (j = 0; j < filter->nb_inputs; j++) {
 296             AVFilterLink *link = filter->inputs[j];
 297             int convert_needed = 0;
 298
 299             if (!link)
 300                 continue;
 301
 302             if (link->in_formats != link->out_formats &&
 303                 !ff_merge_formats(link->in_formats,
 304                                         link->out_formats))
 305                 convert_needed = 1;
 306             if (link->type == AVMEDIA_TYPE_AUDIO) {
 307                 if (link->in_channel_layouts != link->out_channel_layouts &&
 308                     !ff_merge_channel_layouts(link->in_channel_layouts,
 309                                               link->out_channel_layouts))
 310                     convert_needed = 1;
 311                 if (link->in_samplerates != link->out_samplerates &&
 312                     !ff_merge_samplerates(link->in_samplerates,
 313                                           link->out_samplerates))
 314                     convert_needed = 1;
 315             }
 316
 317             if (convert_needed) {
 318                 AVFilterContext *convert;
 319                 AVFilter *filter;
 320                 AVFilterLink *inlink, *outlink;
 321                 char scale_args[256];
 322                 char inst_name[30];
 323
 324                 /* couldn't merge format lists. auto-insert conversion filter */
 325                 switch (link->type) {
 326                 case AVMEDIA_TYPE_VIDEO:
 327                     if (!(filter = avfilter_get_by_name("scale"))) {
 328                         av_log(log_ctx, AV_LOG_ERROR, "'scale' filter "
 329                                "not present, cannot convert pixel formats.\n");
 330                         return AVERROR(EINVAL);
 331                     }
 332
 333                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
 334                              scaler_count++);
 335
 336                     if ((ret = avfilter_graph_create_filter(&convert, filter,
 337                                                             inst_name, graph->scale_sws_opts, NULL,
 338                                                             graph)) < 0)
 339                         return ret;
 340                     break;
 341                 case AVMEDIA_TYPE_AUDIO:
 342                     if (!(filter = avfilter_get_by_name("resample"))) {
 343                         av_log(log_ctx, AV_LOG_ERROR, "'resample' filter "
 344                                "not present, cannot convert audio formats.\n");
 345                         return AVERROR(EINVAL);
 346                     }
 347
 348                     snprintf(inst_name, sizeof(inst_name), "auto-inserted resampler %d",
 349                              resampler_count++);
 350                     scale_args[0] = '\0';
 351                     if (graph->resample_lavr_opts)
 352                         snprintf(scale_args, sizeof(scale_args), "%s",
 353                                  graph->resample_lavr_opts);
 354                     if ((ret = avfilter_graph_create_filter(&convert, filter,
 355                                                             inst_name, scale_args,
 356                                                             NULL, graph)) < 0)
 357                         return ret;
 358                     break;
 359                 default:
 360                     return AVERROR(EINVAL);
 361                 }
 362
 363                 if ((ret = avfilter_insert_filter(link, convert, 0, 0)) < 0)
 364                     return ret;
 365
 366                 convert->filter->query_formats(convert);
 367                 inlink  = convert->inputs[0];
 368                 outlink = convert->outputs[0];
 369                 if (!ff_merge_formats( inlink->in_formats,  inlink->out_formats) ||
 370                     !ff_merge_formats(outlink->in_formats, outlink->out_formats))
 371                     ret |= AVERROR(ENOSYS);
 372                 if (inlink->type == AVMEDIA_TYPE_AUDIO &&
 373                     (!ff_merge_samplerates(inlink->in_samplerates,
 374                                            inlink->out_samplerates) ||
 375                      !ff_merge_channel_layouts(inlink->in_channel_layouts,
 376                                                inlink->out_channel_layouts)))
 377                     ret |= AVERROR(ENOSYS);
 378                 if (outlink->type == AVMEDIA_TYPE_AUDIO &&
 379                     (!ff_merge_samplerates(outlink->in_samplerates,
 380                                            outlink->out_samplerates) ||
 381                      !ff_merge_channel_layouts(outlink->in_channel_layouts,
 382                                                outlink->out_channel_layouts)))
 383                     ret |= AVERROR(ENOSYS);
 384
 385                 if (ret < 0) {
 386                     av_log(log_ctx, AV_LOG_ERROR,
 387                            "Impossible to convert between the formats supported by the filter "
 388                            "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
 389                     return ret;
 390                 }
 391             }
 392         }
 393     }
 394
 395     return 0;
 396 }
 397
 398 static int pick_format(AVFilterLink *link)
 399 {
 400     if (!link || !link->in_formats)
 401         return 0;
 402
 403     link->in_formats->nb_formats = 1;
 404     link->format = link->in_formats->formats[0];
 405
 406     if (link->type == AVMEDIA_TYPE_AUDIO) {
 407         if (!link->in_samplerates->nb_formats) {
 408             av_log(link->src, AV_LOG_ERROR, "Cannot select sample rate for"
 409                    " the link between filters %s and %s.\n", link->src->name,
 410                    link->dst->name);
 411             return AVERROR(EINVAL);
 412         }
 413         link->in_samplerates->nb_formats = 1;
 414         link->sample_rate = link->in_samplerates->formats[0];
 415
 416         if (!link->in_channel_layouts->nb_channel_layouts) {
 417             av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout for"
 418                    "the link between filters %s and %s.\n", link->src->name,
 419                    link->dst->name);
 420             return AVERROR(EINVAL);
 421         }
 422         link->in_channel_layouts->nb_channel_layouts = 1;
 423         link->channel_layout = link->in_channel_layouts->channel_layouts[0];
 424     }
 425
 426     ff_formats_unref(&link->in_formats);
 427     ff_formats_unref(&link->out_formats);
 428     ff_formats_unref(&link->in_samplerates);
 429     ff_formats_unref(&link->out_samplerates);
 430     ff_channel_layouts_unref(&link->in_channel_layouts);
 431     ff_channel_layouts_unref(&link->out_channel_layouts);
 432
 433     return 0;
 434 }
 435
 436 #define REDUCE_FORMATS(fmt_type, list_type, list, var, nb, add_format) \
 437 do {                                                                   \
 438     for (i = 0; i < filter->nb_inputs; i++) {                          \
 439         AVFilterLink *link = filter->inputs[i];                        \
 440         fmt_type fmt;                                                  \
 441                                                                        \
 442         if (!link->out_ ## list || link->out_ ## list->nb != 1)        \
 443             continue;                                                  \
 444         fmt = link->out_ ## list->var[0];                              \
 445                                                                        \
 446         for (j = 0; j < filter->nb_outputs; j++) {                     \
 447             AVFilterLink *out_link = filter->outputs[j];               \
 448             list_type *fmts;                                           \
 449                                                                        \
 450             if (link->type != out_link->type ||                        \
 451                 out_link->in_ ## list->nb == 1)                        \
 452                 continue;                                              \
 453             fmts = out_link->in_ ## list;                              \
 454                                                                        \
 455             if (!out_link->in_ ## list->nb) {                          \
 456                 add_format(&out_link->in_ ##list, fmt);                \
 457                 break;                                                 \
 458             }                                                          \
 459                                                                        \
 460             for (k = 0; k < out_link->in_ ## list->nb; k++)            \
 461                 if (fmts->var[k] == fmt) {                             \
 462                     fmts->var[0]  = fmt;                               \
 463                     fmts->nb = 1;                                      \
 464                     ret = 1;                                           \
 465                     break;                                             \
 466                 }                                                      \
 467         }                                                              \
 468     }                                                                  \
 469 } while (0)
 470
 471 static int reduce_formats_on_filter(AVFilterContext *filter)
 472 {
 473     int i, j, k, ret = 0;
 474
 475     REDUCE_FORMATS(int,      AVFilterFormats,        formats,         formats,
 476                    nb_formats, ff_add_format);
 477     REDUCE_FORMATS(int,      AVFilterFormats,        samplerates,     formats,
 478                    nb_formats, ff_add_format);
 479     REDUCE_FORMATS(uint64_t, AVFilterChannelLayouts, channel_layouts,
 480                    channel_layouts, nb_channel_layouts, ff_add_channel_layout);
 481
 482     return ret;
 483 }
 484
 485 static void reduce_formats(AVFilterGraph *graph)
 486 {
 487     int i, reduced;
 488
 489     do {
 490         reduced = 0;
 491
 492         for (i = 0; i < graph->nb_filters; i++)
 493             reduced |= reduce_formats_on_filter(graph->filters[i]);
 494     } while (reduced);
 495 }
 496
 497 static void swap_samplerates_on_filter(AVFilterContext *filter)
 498 {
 499     AVFilterLink *link = NULL;
 500     int sample_rate;
 501     int i, j;
 502
 503     for (i = 0; i < filter->nb_inputs; i++) {
 504         link = filter->inputs[i];
 505
 506         if (link->type == AVMEDIA_TYPE_AUDIO &&
 507             link->out_samplerates->nb_formats== 1)
 508             break;
 509     }
 510     if (i == filter->nb_inputs)
 511         return;
 512
 513     sample_rate = link->out_samplerates->formats[0];
 514
 515     for (i = 0; i < filter->nb_outputs; i++) {
 516         AVFilterLink *outlink = filter->outputs[i];
 517         int best_idx, best_diff = INT_MAX;
 518
 519         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
 520             outlink->in_samplerates->nb_formats < 2)
 521             continue;
 522
 523         for (j = 0; j < outlink->in_samplerates->nb_formats; j++) {
 524             int diff = abs(sample_rate - outlink->in_samplerates->formats[j]);
 525
 526             if (diff < best_diff) {
 527                 best_diff = diff;
 528                 best_idx  = j;
 529             }
 530         }
 531         FFSWAP(int, outlink->in_samplerates->formats[0],
 532                outlink->in_samplerates->formats[best_idx]);
 533     }
 534 }
 535
 536 static void swap_samplerates(AVFilterGraph *graph)
 537 {
 538     int i;
 539
 540     for (i = 0; i < graph->nb_filters; i++)
 541         swap_samplerates_on_filter(graph->filters[i]);
 542 }
 543
 544 #define CH_CENTER_PAIR (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)
 545 #define CH_FRONT_PAIR  (AV_CH_FRONT_LEFT           | AV_CH_FRONT_RIGHT)
 546 #define CH_STEREO_PAIR (AV_CH_STEREO_LEFT          | AV_CH_STEREO_RIGHT)
 547 #define CH_WIDE_PAIR   (AV_CH_WIDE_LEFT            | AV_CH_WIDE_RIGHT)
 548 #define CH_SIDE_PAIR   (AV_CH_SIDE_LEFT            | AV_CH_SIDE_RIGHT)
 549 #define CH_DIRECT_PAIR (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT)
 550 #define CH_BACK_PAIR   (AV_CH_BACK_LEFT            | AV_CH_BACK_RIGHT)
 551
 552 /* allowable substitutions for channel pairs when comparing layouts,
 553  * ordered by priority for both values */
 554 static const uint64_t ch_subst[][2] = {
 555     { CH_FRONT_PAIR,      CH_CENTER_PAIR     },
 556     { CH_FRONT_PAIR,      CH_WIDE_PAIR       },
 557     { CH_FRONT_PAIR,      AV_CH_FRONT_CENTER },
 558     { CH_CENTER_PAIR,     CH_FRONT_PAIR      },
 559     { CH_CENTER_PAIR,     CH_WIDE_PAIR       },
 560     { CH_CENTER_PAIR,     AV_CH_FRONT_CENTER },
 561     { CH_WIDE_PAIR,       CH_FRONT_PAIR      },
 562     { CH_WIDE_PAIR,       CH_CENTER_PAIR     },
 563     { CH_WIDE_PAIR,       AV_CH_FRONT_CENTER },
 564     { AV_CH_FRONT_CENTER, CH_FRONT_PAIR      },
 565     { AV_CH_FRONT_CENTER, CH_CENTER_PAIR     },
 566     { AV_CH_FRONT_CENTER, CH_WIDE_PAIR       },
 567     { CH_SIDE_PAIR,       CH_DIRECT_PAIR     },
 568     { CH_SIDE_PAIR,       CH_BACK_PAIR       },
 569     { CH_SIDE_PAIR,       AV_CH_BACK_CENTER  },
 570     { CH_BACK_PAIR,       CH_DIRECT_PAIR     },
 571     { CH_BACK_PAIR,       CH_SIDE_PAIR       },
 572     { CH_BACK_PAIR,       AV_CH_BACK_CENTER  },
 573     { AV_CH_BACK_CENTER,  CH_BACK_PAIR       },
 574     { AV_CH_BACK_CENTER,  CH_DIRECT_PAIR     },
 575     { AV_CH_BACK_CENTER,  CH_SIDE_PAIR       },
 576 };
 577
 578 static void swap_channel_layouts_on_filter(AVFilterContext *filter)
 579 {
 580     AVFilterLink *link = NULL;
 581     int i, j, k;
 582
 583     for (i = 0; i < filter->nb_inputs; i++) {
 584         link = filter->inputs[i];
 585
 586         if (link->type == AVMEDIA_TYPE_AUDIO &&
 587             link->out_channel_layouts->nb_channel_layouts == 1)
 588             break;
 589     }
 590     if (i == filter->nb_inputs)
 591         return;
 592
 593     for (i = 0; i < filter->nb_outputs; i++) {
 594         AVFilterLink *outlink = filter->outputs[i];
 595         int best_idx = -1, best_score = INT_MIN, best_count_diff = INT_MAX;
 596
 597         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
 598             outlink->in_channel_layouts->nb_channel_layouts < 2)
 599             continue;
 600
 601         for (j = 0; j < outlink->in_channel_layouts->nb_channel_layouts; j++) {
 602             uint64_t  in_chlayout = link->out_channel_layouts->channel_layouts[0];
 603             uint64_t out_chlayout = outlink->in_channel_layouts->channel_layouts[j];
 604             int  in_channels      = av_get_channel_layout_nb_channels(in_chlayout);
 605             int out_channels      = av_get_channel_layout_nb_channels(out_chlayout);
 606             int count_diff        = out_channels - in_channels;
 607             int matched_channels, extra_channels;
 608             int score = 0;
 609
 610             /* channel substitution */
 611             for (k = 0; k < FF_ARRAY_ELEMS(ch_subst); k++) {
 612                 uint64_t cmp0 = ch_subst[k][0];
 613                 uint64_t cmp1 = ch_subst[k][1];
 614                 if (( in_chlayout & cmp0) && (!(out_chlayout & cmp0)) &&
 615                     (out_chlayout & cmp1) && (!( in_chlayout & cmp1))) {
 616                     in_chlayout  &= ~cmp0;
 617                     out_chlayout &= ~cmp1;
 618                     /* add score for channel match, minus a deduction for
 619                        having to do the substitution */
 620                     score += 10 * av_get_channel_layout_nb_channels(cmp1) - 2;
 621                 }
 622             }
 623
 624             /* no penalty for LFE channel mismatch */
 625             if ( (in_chlayout & AV_CH_LOW_FREQUENCY) &&
 626                 (out_chlayout & AV_CH_LOW_FREQUENCY))
 627                 score += 10;
 628             in_chlayout  &= ~AV_CH_LOW_FREQUENCY;
 629             out_chlayout &= ~AV_CH_LOW_FREQUENCY;
 630
 631             matched_channels = av_get_channel_layout_nb_channels(in_chlayout &
 632                                                                  out_chlayout);
 633             extra_channels   = av_get_channel_layout_nb_channels(out_chlayout &
 634                                                                  (~in_chlayout));
 635             score += 10 * matched_channels - 5 * extra_channels;
 636
 637             if (score > best_score ||
 638                 (count_diff < best_count_diff && score == best_score)) {
 639                 best_score = score;
 640                 best_idx   = j;
 641                 best_count_diff = count_diff;
 642             }
 643         }
 644         av_assert0(best_idx >= 0);
 645         FFSWAP(uint64_t, outlink->in_channel_layouts->channel_layouts[0],
 646                outlink->in_channel_layouts->channel_layouts[best_idx]);
 647     }
 648
 649 }
 650
 651 static void swap_channel_layouts(AVFilterGraph *graph)
 652 {
 653     int i;
 654
 655     for (i = 0; i < graph->nb_filters; i++)
 656         swap_channel_layouts_on_filter(graph->filters[i]);
 657 }
 658
 659 static void swap_sample_fmts_on_filter(AVFilterContext *filter)
 660 {
 661     AVFilterLink *link = NULL;
 662     int format, bps;
 663     int i, j;
 664
 665     for (i = 0; i < filter->nb_inputs; i++) {
 666         link = filter->inputs[i];
 667
 668         if (link->type == AVMEDIA_TYPE_AUDIO &&
 669             link->out_formats->nb_formats == 1)
 670             break;
 671     }
 672     if (i == filter->nb_inputs)
 673         return;
 674
 675     format = link->out_formats->formats[0];
 676     bps    = av_get_bytes_per_sample(format);
 677
 678     for (i = 0; i < filter->nb_outputs; i++) {
 679         AVFilterLink *outlink = filter->outputs[i];
 680         int best_idx = -1, best_score = INT_MIN;
 681
 682         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
 683             outlink->in_formats->nb_formats < 2)
 684             continue;
 685
 686         for (j = 0; j < outlink->in_formats->nb_formats; j++) {
 687             int out_format = outlink->in_formats->formats[j];
 688             int out_bps    = av_get_bytes_per_sample(out_format);
 689             int score;
 690
 691             if (av_get_packed_sample_fmt(out_format) == format ||
 692                 av_get_planar_sample_fmt(out_format) == format) {
 693                 best_idx   = j;
 694                 break;
 695             }
 696
 697             /* for s32 and float prefer double to prevent loss of information */
 698             if (bps == 4 && out_bps == 8) {
 699                 best_idx = j;
 700                 break;
 701             }
 702
 703             /* prefer closest higher or equal bps */
 704             score = -abs(out_bps - bps);
 705             if (out_bps >= bps)
 706                 score += INT_MAX/2;
 707
 708             if (score > best_score) {
 709                 best_score = score;
 710                 best_idx   = j;
 711             }
 712         }
 713         av_assert0(best_idx >= 0);
 714         FFSWAP(int, outlink->in_formats->formats[0],
 715                outlink->in_formats->formats[best_idx]);
 716     }
 717 }
 718
 719 static void swap_sample_fmts(AVFilterGraph *graph)
 720 {
 721     int i;
 722
 723     for (i = 0; i < graph->nb_filters; i++)
 724         swap_sample_fmts_on_filter(graph->filters[i]);
 725
 726 }
 727
 728 static int pick_formats(AVFilterGraph *graph)
 729 {
 730     int i, j, ret;
 731
 732     for (i = 0; i < graph->nb_filters; i++) {
 733         AVFilterContext *filter = graph->filters[i];
 734
 735         for (j = 0; j < filter->nb_inputs; j++)
 736             if ((ret = pick_format(filter->inputs[j])) < 0)
 737                 return ret;
 738         for (j = 0; j < filter->nb_outputs; j++)
 739             if ((ret = pick_format(filter->outputs[j])) < 0)
 740                 return ret;
 741     }
 742     return 0;
 743 }
 744
 745 /**
 746  * Configure the formats of all the links in the graph.
 747  */
 748 static int graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
 749 {
 750     int ret;
 751
 752     /* find supported formats from sub-filters, and merge along links */
 753     if ((ret = query_formats(graph, log_ctx)) < 0)
 754         return ret;
 755
 756     /* Once everything is merged, it's possible that we'll still have
 757      * multiple valid media format choices. We try to minimize the amount
 758      * of format conversion inside filters */
 759     reduce_formats(graph);
 760
 761     /* for audio filters, ensure the best format, sample rate and channel layout
 762      * is selected */
 763     swap_sample_fmts(graph);
 764     swap_samplerates(graph);
 765     swap_channel_layouts(graph);
 766
 767     if ((ret = pick_formats(graph)) < 0)
 768         return ret;
 769
 770     return 0;
 771 }
 772
 773 static int graph_insert_fifos(AVFilterGraph *graph, AVClass *log_ctx)
 774 {
 775     AVFilterContext *f;
 776     int i, j, ret;
 777     int fifo_count = 0;
 778
 779     for (i = 0; i < graph->nb_filters; i++) {
 780         f = graph->filters[i];
 781
 782         for (j = 0; j < f->nb_inputs; j++) {
 783             AVFilterLink *link = f->inputs[j];
 784             AVFilterContext *fifo_ctx;
 785             AVFilter *fifo;
 786             char name[32];
 787
 788             if (!link->dstpad->needs_fifo)
 789                 continue;
 790
 791             fifo = f->inputs[j]->type == AVMEDIA_TYPE_VIDEO ?
 792                    avfilter_get_by_name("fifo") :
 793                    avfilter_get_by_name("afifo");
 794
 795             snprintf(name, sizeof(name), "auto-inserted fifo %d", fifo_count++);
 796
 797             ret = avfilter_graph_create_filter(&fifo_ctx, fifo, name, NULL,
 798                                                NULL, graph);
 799             if (ret < 0)
 800                 return ret;
 801
 802             ret = avfilter_insert_filter(link, fifo_ctx, 0, 0);
 803             if (ret < 0)
 804                 return ret;
 805         }
 806     }
 807
 808     return 0;
 809 }
 810
 811 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
 812 {
 813     int ret;
 814
 815     if ((ret = graph_check_validity(graphctx, log_ctx)))
 816         return ret;
 817     if ((ret = graph_insert_fifos(graphctx, log_ctx)) < 0)
 818         return ret;
 819     if ((ret = graph_config_formats(graphctx, log_ctx)))
 820         return ret;
 821     if ((ret = graph_config_links(graphctx, log_ctx)))
 822         return ret;
 823
 824     return 0;
 825 }