libavfilter/avfilter.c

   1 /*
   2  * filter layer
   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 /* #define DEBUG */
  23
  24 #include "libavutil/pixdesc.h"
  25 #include "libavutil/rational.h"
  26 #include "libavutil/audioconvert.h"
  27 #include "libavutil/imgutils.h"
  28 #include "avfilter.h"
  29 #include "internal.h"
  30
  31 unsigned avfilter_version(void) {
  32     return LIBAVFILTER_VERSION_INT;
  33 }
  34
  35 const char *avfilter_configuration(void)
  36 {
  37     return LIBAV_CONFIGURATION;
  38 }
  39
  40 const char *avfilter_license(void)
  41 {
  42 #define LICENSE_PREFIX "libavfilter license: "
  43     return LICENSE_PREFIX LIBAV_LICENSE + sizeof(LICENSE_PREFIX) - 1;
  44 }
  45
  46 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask)
  47 {
  48     AVFilterBufferRef *ret = av_malloc(sizeof(AVFilterBufferRef));
  49     if (!ret)
  50         return NULL;
  51     *ret = *ref;
  52     if (ref->type == AVMEDIA_TYPE_VIDEO) {
  53         ret->video = av_malloc(sizeof(AVFilterBufferRefVideoProps));
  54         if (!ret->video) {
  55             av_free(ret);
  56             return NULL;
  57         }
  58         *ret->video = *ref->video;
  59     } else if (ref->type == AVMEDIA_TYPE_AUDIO) {
  60         ret->audio = av_malloc(sizeof(AVFilterBufferRefAudioProps));
  61         if (!ret->audio) {
  62             av_free(ret);
  63             return NULL;
  64         }
  65         *ret->audio = *ref->audio;
  66     }
  67     ret->perms &= pmask;
  68     ret->buf->refcount ++;
  69     return ret;
  70 }
  71
  72 void avfilter_unref_buffer(AVFilterBufferRef *ref)
  73 {
  74     if (!ref)
  75         return;
  76     if (!(--ref->buf->refcount))
  77         ref->buf->free(ref->buf);
  78     av_free(ref->video);
  79     av_free(ref->audio);
  80     av_free(ref);
  81 }
  82
  83 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
  84                          AVFilterPad **pads, AVFilterLink ***links,
  85                          AVFilterPad *newpad)
  86 {
  87     unsigned i;
  88
  89     idx = FFMIN(idx, *count);
  90
  91     *pads  = av_realloc(*pads,  sizeof(AVFilterPad)   * (*count + 1));
  92     *links = av_realloc(*links, sizeof(AVFilterLink*) * (*count + 1));
  93     memmove(*pads +idx+1, *pads +idx, sizeof(AVFilterPad)   * (*count-idx));
  94     memmove(*links+idx+1, *links+idx, sizeof(AVFilterLink*) * (*count-idx));
  95     memcpy(*pads+idx, newpad, sizeof(AVFilterPad));
  96     (*links)[idx] = NULL;
  97
  98     (*count)++;
  99     for (i = idx+1; i < *count; i++)
 100         if (*links[i])
 101             (*(unsigned *)((uint8_t *) *links[i] + padidx_off))++;
 102 }
 103
 104 int avfilter_link(AVFilterContext *src, unsigned srcpad,
 105                   AVFilterContext *dst, unsigned dstpad)
 106 {
 107     AVFilterLink *link;
 108
 109     if (src->output_count <= srcpad || dst->input_count <= dstpad ||
 110         src->outputs[srcpad]        || dst->inputs[dstpad])
 111         return -1;
 112
 113     if (src->output_pads[srcpad].type != dst->input_pads[dstpad].type) {
 114         av_log(src, AV_LOG_ERROR,
 115                "Media type mismatch between the '%s' filter output pad %d and the '%s' filter input pad %d\n",
 116                src->name, srcpad, dst->name, dstpad);
 117         return AVERROR(EINVAL);
 118     }
 119
 120     src->outputs[srcpad] =
 121     dst-> inputs[dstpad] = link = av_mallocz(sizeof(AVFilterLink));
 122
 123     link->src     = src;
 124     link->dst     = dst;
 125     link->srcpad  = &src->output_pads[srcpad];
 126     link->dstpad  = &dst->input_pads[dstpad];
 127     link->type    = src->output_pads[srcpad].type;
 128     assert(PIX_FMT_NONE == -1 && AV_SAMPLE_FMT_NONE == -1);
 129     link->format  = -1;
 130
 131     return 0;
 132 }
 133
 134 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
 135                            unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)
 136 {
 137     int ret;
 138     unsigned dstpad_idx = link->dstpad - link->dst->input_pads;
 139
 140     av_log(link->dst, AV_LOG_INFO, "auto-inserting filter '%s' "
 141            "between the filter '%s' and the filter '%s'\n",
 142            filt->name, link->src->name, link->dst->name);
 143
 144     link->dst->inputs[dstpad_idx] = NULL;
 145     if ((ret = avfilter_link(filt, filt_dstpad_idx, link->dst, dstpad_idx)) < 0) {
 146         /* failed to link output filter to new filter */
 147         link->dst->inputs[dstpad_idx] = link;
 148         return ret;
 149     }
 150
 151     /* re-hookup the link to the new destination filter we inserted */
 152     link->dst = filt;
 153     link->dstpad = &filt->input_pads[filt_srcpad_idx];
 154     filt->inputs[filt_srcpad_idx] = link;
 155
 156     /* if any information on supported media formats already exists on the
 157      * link, we need to preserve that */
 158     if (link->out_formats)
 159         avfilter_formats_changeref(&link->out_formats,
 160                                    &filt->outputs[filt_dstpad_idx]->out_formats);
 161
 162     return 0;
 163 }
 164
 165 int avfilter_config_links(AVFilterContext *filter)
 166 {
 167     int (*config_link)(AVFilterLink *);
 168     unsigned i;
 169     int ret;
 170
 171     for (i = 0; i < filter->input_count; i ++) {
 172         AVFilterLink *link = filter->inputs[i];
 173
 174         if (!link) continue;
 175
 176         switch (link->init_state) {
 177         case AVLINK_INIT:
 178             continue;
 179         case AVLINK_STARTINIT:
 180             av_log(filter, AV_LOG_INFO, "circular filter chain detected\n");
 181             return 0;
 182         case AVLINK_UNINIT:
 183             link->init_state = AVLINK_STARTINIT;
 184
 185             if ((ret = avfilter_config_links(link->src)) < 0)
 186                 return ret;
 187
 188             if (!(config_link = link->srcpad->config_props))
 189                 config_link  = avfilter_default_config_output_link;
 190             if ((ret = config_link(link)) < 0)
 191                 return ret;
 192
 193             if (link->time_base.num == 0 && link->time_base.den == 0)
 194                 link->time_base = link->src && link->src->input_count ?
 195                     link->src->inputs[0]->time_base : AV_TIME_BASE_Q;
 196
 197             if (link->sample_aspect_ratio.num == 0 && link->sample_aspect_ratio.den == 0)
 198                 link->sample_aspect_ratio = link->src->input_count ?
 199                     link->src->inputs[0]->sample_aspect_ratio : (AVRational){1,1};
 200
 201             if (link->sample_rate == 0 && link->src && link->src->input_count)
 202                 link->sample_rate = link->src->inputs[0]->sample_rate;
 203
 204             if (link->channel_layout == 0 && link->src && link->src->input_count)
 205                 link->channel_layout = link->src->inputs[0]->channel_layout;
 206
 207             if ((config_link = link->dstpad->config_props))
 208                 if ((ret = config_link(link)) < 0)
 209                     return ret;
 210
 211             link->init_state = AVLINK_INIT;
 212         }
 213     }
 214
 215     return 0;
 216 }
 217
 218 static char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms)
 219 {
 220     snprintf(buf, buf_size, "%s%s%s%s%s%s",
 221              perms & AV_PERM_READ      ? "r" : "",
 222              perms & AV_PERM_WRITE     ? "w" : "",
 223              perms & AV_PERM_PRESERVE  ? "p" : "",
 224              perms & AV_PERM_REUSE     ? "u" : "",
 225              perms & AV_PERM_REUSE2    ? "U" : "",
 226              perms & AV_PERM_NEG_LINESIZES ? "n" : "");
 227     return buf;
 228 }
 229
 230 static void ff_dlog_ref(void *ctx, AVFilterBufferRef *ref, int end)
 231 {
 232     av_unused char buf[16];
 233     av_dlog(ctx,
 234             "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
 235             ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],
 236             ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
 237             ref->pts, ref->pos);
 238
 239     if (ref->video) {
 240         av_dlog(ctx, " a:%d/%d s:%dx%d i:%c",
 241                 ref->video->pixel_aspect.num, ref->video->pixel_aspect.den,
 242                 ref->video->w, ref->video->h,
 243                 !ref->video->interlaced     ? 'P' :         /* Progressive  */
 244                 ref->video->top_field_first ? 'T' : 'B');   /* Top / Bottom */
 245     }
 246     if (ref->audio) {
 247         av_dlog(ctx, " cl:%"PRId64"d sn:%d s:%d sr:%d p:%d",
 248                 ref->audio->channel_layout,
 249                 ref->audio->nb_samples,
 250                 ref->audio->size,
 251                 ref->audio->sample_rate,
 252                 ref->audio->planar);
 253     }
 254
 255     av_dlog(ctx, "]%s", end ? "\n" : "");
 256 }
 257
 258 static void ff_dlog_link(void *ctx, AVFilterLink *link, int end)
 259 {
 260     if (link->type == AVMEDIA_TYPE_VIDEO) {
 261         av_dlog(ctx,
 262                 "link[%p s:%dx%d fmt:%-16s %-16s->%-16s]%s",
 263                 link, link->w, link->h,
 264                 av_pix_fmt_descriptors[link->format].name,
 265                 link->src ? link->src->filter->name : "",
 266                 link->dst ? link->dst->filter->name : "",
 267                 end ? "\n" : "");
 268     } else {
 269         char buf[128];
 270         av_get_channel_layout_string(buf, sizeof(buf), -1, link->channel_layout);
 271
 272         av_dlog(ctx,
 273                 "link[%p r:%"PRId64" cl:%s fmt:%-16s %-16s->%-16s]%s",
 274                 link, link->sample_rate, buf,
 275                 av_get_sample_fmt_name(link->format),
 276                 link->src ? link->src->filter->name : "",
 277                 link->dst ? link->dst->filter->name : "",
 278                 end ? "\n" : "");
 279     }
 280 }
 281
 282 #define FF_DPRINTF_START(ctx, func) av_dlog(NULL, "%-16s: ", #func)
 283
 284 AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
 285 {
 286     AVFilterBufferRef *ret = NULL;
 287
 288     av_unused char buf[16];
 289     FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0);
 290     av_dlog(NULL, " perms:%s w:%d h:%d\n", ff_get_ref_perms_string(buf, sizeof(buf), perms), w, h);
 291
 292     if (link->dstpad->get_video_buffer)
 293         ret = link->dstpad->get_video_buffer(link, perms, w, h);
 294
 295     if (!ret)
 296         ret = avfilter_default_get_video_buffer(link, perms, w, h);
 297
 298     if (ret)
 299         ret->type = AVMEDIA_TYPE_VIDEO;
 300
 301     FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " returning "); ff_dlog_ref(NULL, ret, 1);
 302
 303     return ret;
 304 }
 305
 306 AVFilterBufferRef *
 307 avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
 308                                           int w, int h, enum PixelFormat format)
 309 {
 310     AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
 311     AVFilterBufferRef *picref = av_mallocz(sizeof(AVFilterBufferRef));
 312
 313     if (!pic || !picref)
 314         goto fail;
 315
 316     picref->buf = pic;
 317     picref->buf->free = ff_avfilter_default_free_buffer;
 318     if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
 319         goto fail;
 320
 321     pic->w = picref->video->w = w;
 322     pic->h = picref->video->h = h;
 323
 324     /* make sure the buffer gets read permission or it's useless for output */
 325     picref->perms = perms | AV_PERM_READ;
 326
 327     pic->refcount = 1;
 328     picref->type = AVMEDIA_TYPE_VIDEO;
 329     pic->format = picref->format = format;
 330
 331     memcpy(pic->data,        data,          sizeof(pic->data));
 332     memcpy(pic->linesize,    linesize,      sizeof(pic->linesize));
 333     memcpy(picref->data,     pic->data,     sizeof(picref->data));
 334     memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
 335
 336     return picref;
 337
 338 fail:
 339     if (picref && picref->video)
 340         av_free(picref->video);
 341     av_free(picref);
 342     av_free(pic);
 343     return NULL;
 344 }
 345
 346 AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms,
 347                                              enum AVSampleFormat sample_fmt, int size,
 348                                              int64_t channel_layout, int planar)
 349 {
 350     AVFilterBufferRef *ret = NULL;
 351
 352     if (link->dstpad->get_audio_buffer)
 353         ret = link->dstpad->get_audio_buffer(link, perms, sample_fmt, size, channel_layout, planar);
 354
 355     if (!ret)
 356         ret = avfilter_default_get_audio_buffer(link, perms, sample_fmt, size, channel_layout, planar);
 357
 358     if (ret)
 359         ret->type = AVMEDIA_TYPE_AUDIO;
 360
 361     return ret;
 362 }
 363
 364 int avfilter_request_frame(AVFilterLink *link)
 365 {
 366     FF_DPRINTF_START(NULL, request_frame); ff_dlog_link(NULL, link, 1);
 367
 368     if (link->srcpad->request_frame)
 369         return link->srcpad->request_frame(link);
 370     else if (link->src->inputs[0])
 371         return avfilter_request_frame(link->src->inputs[0]);
 372     else return -1;
 373 }
 374
 375 int avfilter_poll_frame(AVFilterLink *link)
 376 {
 377     int i, min = INT_MAX;
 378
 379     if (link->srcpad->poll_frame)
 380         return link->srcpad->poll_frame(link);
 381
 382     for (i = 0; i < link->src->input_count; i++) {
 383         int val;
 384         if (!link->src->inputs[i])
 385             return -1;
 386         val = avfilter_poll_frame(link->src->inputs[i]);
 387         min = FFMIN(min, val);
 388     }
 389
 390     return min;
 391 }
 392
 393 /* XXX: should we do the duplicating of the picture ref here, instead of
 394  * forcing the source filter to do it? */
 395 void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
 396 {
 397     void (*start_frame)(AVFilterLink *, AVFilterBufferRef *);
 398     AVFilterPad *dst = link->dstpad;
 399     int perms = picref->perms;
 400
 401     FF_DPRINTF_START(NULL, start_frame); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " "); ff_dlog_ref(NULL, picref, 1);
 402
 403     if (!(start_frame = dst->start_frame))
 404         start_frame = avfilter_default_start_frame;
 405
 406     if (picref->linesize[0] < 0)
 407         perms |= AV_PERM_NEG_LINESIZES;
 408     /* prepare to copy the picture if it has insufficient permissions */
 409     if ((dst->min_perms & perms) != dst->min_perms || dst->rej_perms & perms) {
 410         av_log(link->dst, AV_LOG_DEBUG,
 411                 "frame copy needed (have perms %x, need %x, reject %x)\n",
 412                 picref->perms,
 413                 link->dstpad->min_perms, link->dstpad->rej_perms);
 414
 415         link->cur_buf = avfilter_get_video_buffer(link, dst->min_perms, link->w, link->h);
 416         link->src_buf = picref;
 417         avfilter_copy_buffer_ref_props(link->cur_buf, link->src_buf);
 418     }
 419     else
 420         link->cur_buf = picref;
 421
 422     start_frame(link, link->cur_buf);
 423 }
 424
 425 void avfilter_end_frame(AVFilterLink *link)
 426 {
 427     void (*end_frame)(AVFilterLink *);
 428
 429     if (!(end_frame = link->dstpad->end_frame))
 430         end_frame = avfilter_default_end_frame;
 431
 432     end_frame(link);
 433
 434     /* unreference the source picture if we're feeding the destination filter
 435      * a copied version dues to permission issues */
 436     if (link->src_buf) {
 437         avfilter_unref_buffer(link->src_buf);
 438         link->src_buf = NULL;
 439     }
 440 }
 441
 442 void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
 443 {
 444     uint8_t *src[4], *dst[4];
 445     int i, j, vsub;
 446     void (*draw_slice)(AVFilterLink *, int, int, int);
 447
 448     FF_DPRINTF_START(NULL, draw_slice); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " y:%d h:%d dir:%d\n", y, h, slice_dir);
 449
 450     /* copy the slice if needed for permission reasons */
 451     if (link->src_buf) {
 452         vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
 453
 454         for (i = 0; i < 4; i++) {
 455             if (link->src_buf->data[i]) {
 456                 src[i] = link->src_buf-> data[i] +
 457                     (y >> (i==1 || i==2 ? vsub : 0)) * link->src_buf-> linesize[i];
 458                 dst[i] = link->cur_buf->data[i] +
 459                     (y >> (i==1 || i==2 ? vsub : 0)) * link->cur_buf->linesize[i];
 460             } else
 461                 src[i] = dst[i] = NULL;
 462         }
 463
 464         for (i = 0; i < 4; i++) {
 465             int planew =
 466                 av_image_get_linesize(link->format, link->cur_buf->video->w, i);
 467
 468             if (!src[i]) continue;
 469
 470             for (j = 0; j < h >> (i==1 || i==2 ? vsub : 0); j++) {
 471                 memcpy(dst[i], src[i], planew);
 472                 src[i] += link->src_buf->linesize[i];
 473                 dst[i] += link->cur_buf->linesize[i];
 474             }
 475         }
 476     }
 477
 478     if (!(draw_slice = link->dstpad->draw_slice))
 479         draw_slice = avfilter_default_draw_slice;
 480     draw_slice(link, y, h, slice_dir);
 481 }
 482
 483 void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref)
 484 {
 485     void (*filter_samples)(AVFilterLink *, AVFilterBufferRef *);
 486     AVFilterPad *dst = link->dstpad;
 487
 488     FF_DPRINTF_START(NULL, filter_samples); ff_dlog_link(NULL, link, 1);
 489
 490     if (!(filter_samples = dst->filter_samples))
 491         filter_samples = avfilter_default_filter_samples;
 492
 493     /* prepare to copy the samples if the buffer has insufficient permissions */
 494     if ((dst->min_perms & samplesref->perms) != dst->min_perms ||
 495         dst->rej_perms & samplesref->perms) {
 496
 497         av_log(link->dst, AV_LOG_DEBUG,
 498                "Copying audio data in avfilter (have perms %x, need %x, reject %x)\n",
 499                samplesref->perms, link->dstpad->min_perms, link->dstpad->rej_perms);
 500
 501         link->cur_buf = avfilter_default_get_audio_buffer(link, dst->min_perms,
 502                                                           samplesref->format,
 503                                                           samplesref->audio->size,
 504                                                           samplesref->audio->channel_layout,
 505                                                           samplesref->audio->planar);
 506         link->cur_buf->pts                = samplesref->pts;
 507         link->cur_buf->audio->sample_rate = samplesref->audio->sample_rate;
 508
 509         /* Copy actual data into new samples buffer */
 510         memcpy(link->cur_buf->data[0], samplesref->data[0], samplesref->audio->size);
 511
 512         avfilter_unref_buffer(samplesref);
 513     } else
 514         link->cur_buf = samplesref;
 515
 516     filter_samples(link, link->cur_buf);
 517 }
 518
 519 #define MAX_REGISTERED_AVFILTERS_NB 64
 520
 521 static AVFilter *registered_avfilters[MAX_REGISTERED_AVFILTERS_NB + 1];
 522
 523 static int next_registered_avfilter_idx = 0;
 524
 525 AVFilter *avfilter_get_by_name(const char *name)
 526 {
 527     int i;
 528
 529     for (i = 0; registered_avfilters[i]; i++)
 530         if (!strcmp(registered_avfilters[i]->name, name))
 531             return registered_avfilters[i];
 532
 533     return NULL;
 534 }
 535
 536 int avfilter_register(AVFilter *filter)
 537 {
 538     if (next_registered_avfilter_idx == MAX_REGISTERED_AVFILTERS_NB)
 539         return -1;
 540
 541     registered_avfilters[next_registered_avfilter_idx++] = filter;
 542     return 0;
 543 }
 544
 545 AVFilter **av_filter_next(AVFilter **filter)
 546 {
 547     return filter ? ++filter : &registered_avfilters[0];
 548 }
 549
 550 void avfilter_uninit(void)
 551 {
 552     memset(registered_avfilters, 0, sizeof(registered_avfilters));
 553     next_registered_avfilter_idx = 0;
 554 }
 555
 556 static int pad_count(const AVFilterPad *pads)
 557 {
 558     int count;
 559
 560     for(count = 0; pads->name; count ++) pads ++;
 561     return count;
 562 }
 563
 564 static const char *filter_name(void *p)
 565 {
 566     AVFilterContext *filter = p;
 567     return filter->filter->name;
 568 }
 569
 570 static const AVClass avfilter_class = {
 571     "AVFilter",
 572     filter_name,
 573     NULL,
 574     LIBAVUTIL_VERSION_INT,
 575 };
 576
 577 int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name)
 578 {
 579     AVFilterContext *ret;
 580     *filter_ctx = NULL;
 581
 582     if (!filter)
 583         return AVERROR(EINVAL);
 584
 585     ret = av_mallocz(sizeof(AVFilterContext));
 586
 587     ret->av_class = &avfilter_class;
 588     ret->filter   = filter;
 589     ret->name     = inst_name ? av_strdup(inst_name) : NULL;
 590     ret->priv     = av_mallocz(filter->priv_size);
 591
 592     ret->input_count  = pad_count(filter->inputs);
 593     if (ret->input_count) {
 594         ret->input_pads   = av_malloc(sizeof(AVFilterPad) * ret->input_count);
 595         memcpy(ret->input_pads, filter->inputs, sizeof(AVFilterPad) * ret->input_count);
 596         ret->inputs       = av_mallocz(sizeof(AVFilterLink*) * ret->input_count);
 597     }
 598
 599     ret->output_count = pad_count(filter->outputs);
 600     if (ret->output_count) {
 601         ret->output_pads  = av_malloc(sizeof(AVFilterPad) * ret->output_count);
 602         memcpy(ret->output_pads, filter->outputs, sizeof(AVFilterPad) * ret->output_count);
 603         ret->outputs      = av_mallocz(sizeof(AVFilterLink*) * ret->output_count);
 604     }
 605
 606     *filter_ctx = ret;
 607     return 0;
 608 }
 609
 610 void avfilter_free(AVFilterContext *filter)
 611 {
 612     int i;
 613     AVFilterLink *link;
 614
 615     if (filter->filter->uninit)
 616         filter->filter->uninit(filter);
 617
 618     for (i = 0; i < filter->input_count; i++) {
 619         if ((link = filter->inputs[i])) {
 620             if (link->src)
 621                 link->src->outputs[link->srcpad - link->src->output_pads] = NULL;
 622             avfilter_formats_unref(&link->in_formats);
 623             avfilter_formats_unref(&link->out_formats);
 624         }
 625         av_freep(&link);
 626     }
 627     for (i = 0; i < filter->output_count; i++) {
 628         if ((link = filter->outputs[i])) {
 629             if (link->dst)
 630                 link->dst->inputs[link->dstpad - link->dst->input_pads] = NULL;
 631             avfilter_formats_unref(&link->in_formats);
 632             avfilter_formats_unref(&link->out_formats);
 633         }
 634         av_freep(&link);
 635     }
 636
 637     av_freep(&filter->name);
 638     av_freep(&filter->input_pads);
 639     av_freep(&filter->output_pads);
 640     av_freep(&filter->inputs);
 641     av_freep(&filter->outputs);
 642     av_freep(&filter->priv);
 643     av_free(filter);
 644 }
 645
 646 int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque)
 647 {
 648     int ret=0;
 649
 650     if (filter->filter->init)
 651         ret = filter->filter->init(filter, args, opaque);
 652     return ret;
 653 }
 654