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