avfiltergraph.c
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1 /*
2  * filter graphs
3  * Copyright (c) 2008 Vitor Sessak
4  * Copyright (c) 2007 Bobby Bingham
5  *
6  * This file is part of Libav.
7  *
8  * Libav is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * Libav is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include <ctype.h>
24 #include <string.h>
25 
26 #include "libavutil/avassert.h"
27 #include "libavutil/avstring.h"
29 #include "libavutil/common.h"
30 #include "libavutil/log.h"
31 #include "avfilter.h"
32 #include "avfiltergraph.h"
33 #include "formats.h"
34 #include "internal.h"
35 
36 static const AVClass filtergraph_class = {
37  .class_name = "AVFilterGraph",
38  .item_name = av_default_item_name,
39  .version = LIBAVUTIL_VERSION_INT,
40 };
41 
43 {
44  AVFilterGraph *ret = av_mallocz(sizeof(AVFilterGraph));
45  if (!ret)
46  return NULL;
48  return ret;
49 }
50 
52 {
53  if (!*graph)
54  return;
55  for (; (*graph)->filter_count > 0; (*graph)->filter_count--)
56  avfilter_free((*graph)->filters[(*graph)->filter_count - 1]);
57  av_freep(&(*graph)->scale_sws_opts);
58  av_freep(&(*graph)->filters);
59  av_freep(graph);
60 }
61 
63 {
64  AVFilterContext **filters = av_realloc(graph->filters,
65  sizeof(AVFilterContext*) * (graph->filter_count+1));
66  if (!filters)
67  return AVERROR(ENOMEM);
68 
69  graph->filters = filters;
70  graph->filters[graph->filter_count++] = filter;
71 
72  return 0;
73 }
74 
76  const char *name, const char *args, void *opaque,
77  AVFilterGraph *graph_ctx)
78 {
79  int ret;
80 
81  if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
82  goto fail;
83  if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
84  goto fail;
85  if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
86  goto fail;
87  return 0;
88 
89 fail:
90  if (*filt_ctx)
91  avfilter_free(*filt_ctx);
92  *filt_ctx = NULL;
93  return ret;
94 }
95 
104 static int graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
105 {
106  AVFilterContext *filt;
107  int i, j;
108 
109  for (i = 0; i < graph->filter_count; i++) {
110  filt = graph->filters[i];
111 
112  for (j = 0; j < filt->nb_inputs; j++) {
113  if (!filt->inputs[j] || !filt->inputs[j]->src) {
114  av_log(log_ctx, AV_LOG_ERROR,
115  "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
116  filt->input_pads[j].name, filt->name, filt->filter->name);
117  return AVERROR(EINVAL);
118  }
119  }
120 
121  for (j = 0; j < filt->nb_outputs; j++) {
122  if (!filt->outputs[j] || !filt->outputs[j]->dst) {
123  av_log(log_ctx, AV_LOG_ERROR,
124  "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
125  filt->output_pads[j].name, filt->name, filt->filter->name);
126  return AVERROR(EINVAL);
127  }
128  }
129  }
130 
131  return 0;
132 }
133 
139 static int graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
140 {
141  AVFilterContext *filt;
142  int i, ret;
143 
144  for (i=0; i < graph->filter_count; i++) {
145  filt = graph->filters[i];
146 
147  if (!filt->nb_outputs) {
148  if ((ret = avfilter_config_links(filt)))
149  return ret;
150  }
151  }
152 
153  return 0;
154 }
155 
157 {
158  int i;
159 
160  for (i = 0; i < graph->filter_count; i++)
161  if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
162  return graph->filters[i];
163 
164  return NULL;
165 }
166 
167 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
168 {
169  int i, j, ret;
170  int scaler_count = 0, resampler_count = 0;
171 
172  /* ask all the sub-filters for their supported media formats */
173  for (i = 0; i < graph->filter_count; i++) {
174  if (graph->filters[i]->filter->query_formats)
175  graph->filters[i]->filter->query_formats(graph->filters[i]);
176  else
178  }
179 
180  /* go through and merge as many format lists as possible */
181  for (i = 0; i < graph->filter_count; i++) {
182  AVFilterContext *filter = graph->filters[i];
183 
184  for (j = 0; j < filter->nb_inputs; j++) {
185  AVFilterLink *link = filter->inputs[j];
186  int convert_needed = 0;
187 
188  if (!link)
189  continue;
190 
191  if (link->in_formats != link->out_formats &&
193  link->out_formats))
194  convert_needed = 1;
195  if (link->type == AVMEDIA_TYPE_AUDIO) {
196  if (link->in_channel_layouts != link->out_channel_layouts &&
198  link->out_channel_layouts))
199  convert_needed = 1;
200  if (link->in_samplerates != link->out_samplerates &&
202  link->out_samplerates))
203  convert_needed = 1;
204  }
205 
206  if (convert_needed) {
207  AVFilterContext *convert;
208  AVFilter *filter;
209  AVFilterLink *inlink, *outlink;
210  char scale_args[256];
211  char inst_name[30];
212 
213  /* couldn't merge format lists. auto-insert conversion filter */
214  switch (link->type) {
215  case AVMEDIA_TYPE_VIDEO:
216  if (!(filter = avfilter_get_by_name("scale"))) {
217  av_log(log_ctx, AV_LOG_ERROR, "'scale' filter "
218  "not present, cannot convert pixel formats.\n");
219  return AVERROR(EINVAL);
220  }
221 
222  snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
223  scaler_count++);
224  av_strlcpy(scale_args, "0:0", sizeof(scale_args));
225  if (graph->scale_sws_opts) {
226  av_strlcat(scale_args, ":", sizeof(scale_args));
227  av_strlcat(scale_args, graph->scale_sws_opts, sizeof(scale_args));
228  }
229  if ((ret = avfilter_graph_create_filter(&convert, filter,
230  inst_name, scale_args, NULL,
231  graph)) < 0)
232  return ret;
233  break;
234  case AVMEDIA_TYPE_AUDIO:
235  if (!(filter = avfilter_get_by_name("resample"))) {
236  av_log(log_ctx, AV_LOG_ERROR, "'resample' filter "
237  "not present, cannot convert audio formats.\n");
238  return AVERROR(EINVAL);
239  }
240 
241  snprintf(inst_name, sizeof(inst_name), "auto-inserted resampler %d",
242  resampler_count++);
243  if ((ret = avfilter_graph_create_filter(&convert, filter,
244  inst_name, NULL, NULL, graph)) < 0)
245  return ret;
246  break;
247  default:
248  return AVERROR(EINVAL);
249  }
250 
251  if ((ret = avfilter_insert_filter(link, convert, 0, 0)) < 0)
252  return ret;
253 
254  convert->filter->query_formats(convert);
255  inlink = convert->inputs[0];
256  outlink = convert->outputs[0];
257  if (!ff_merge_formats( inlink->in_formats, inlink->out_formats) ||
258  !ff_merge_formats(outlink->in_formats, outlink->out_formats))
259  ret |= AVERROR(ENOSYS);
260  if (inlink->type == AVMEDIA_TYPE_AUDIO &&
262  inlink->out_samplerates) ||
264  inlink->out_channel_layouts)))
265  ret |= AVERROR(ENOSYS);
266  if (outlink->type == AVMEDIA_TYPE_AUDIO &&
268  outlink->out_samplerates) ||
270  outlink->out_channel_layouts)))
271  ret |= AVERROR(ENOSYS);
272 
273  if (ret < 0) {
274  av_log(log_ctx, AV_LOG_ERROR,
275  "Impossible to convert between the formats supported by the filter "
276  "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
277  return ret;
278  }
279  }
280  }
281  }
282 
283  return 0;
284 }
285 
286 static int pick_format(AVFilterLink *link)
287 {
288  if (!link || !link->in_formats)
289  return 0;
290 
291  link->in_formats->format_count = 1;
292  link->format = link->in_formats->formats[0];
293 
294  if (link->type == AVMEDIA_TYPE_AUDIO) {
295  if (!link->in_samplerates->format_count) {
296  av_log(link->src, AV_LOG_ERROR, "Cannot select sample rate for"
297  " the link between filters %s and %s.\n", link->src->name,
298  link->dst->name);
299  return AVERROR(EINVAL);
300  }
301  link->in_samplerates->format_count = 1;
302  link->sample_rate = link->in_samplerates->formats[0];
303 
305  av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout for"
306  "the link between filters %s and %s.\n", link->src->name,
307  link->dst->name);
308  return AVERROR(EINVAL);
309  }
312  }
313 
320 
321  return 0;
322 }
323 
324 #define REDUCE_FORMATS(fmt_type, list_type, list, var, nb, add_format) \
325 do { \
326  for (i = 0; i < filter->nb_inputs; i++) { \
327  AVFilterLink *link = filter->inputs[i]; \
328  fmt_type fmt; \
329  \
330  if (!link->out_ ## list || link->out_ ## list->nb != 1) \
331  continue; \
332  fmt = link->out_ ## list->var[0]; \
333  \
334  for (j = 0; j < filter->nb_outputs; j++) { \
335  AVFilterLink *out_link = filter->outputs[j]; \
336  list_type *fmts; \
337  \
338  if (link->type != out_link->type || \
339  out_link->in_ ## list->nb == 1) \
340  continue; \
341  fmts = out_link->in_ ## list; \
342  \
343  if (!out_link->in_ ## list->nb) { \
344  add_format(&out_link->in_ ##list, fmt); \
345  break; \
346  } \
347  \
348  for (k = 0; k < out_link->in_ ## list->nb; k++) \
349  if (fmts->var[k] == fmt) { \
350  fmts->var[0] = fmt; \
351  fmts->nb = 1; \
352  ret = 1; \
353  break; \
354  } \
355  } \
356  } \
357 } while (0)
358 
360 {
361  int i, j, k, ret = 0;
362 
364  format_count, ff_add_format);
365  REDUCE_FORMATS(int, AVFilterFormats, samplerates, formats,
366  format_count, ff_add_format);
369 
370  return ret;
371 }
372 
373 static void reduce_formats(AVFilterGraph *graph)
374 {
375  int i, reduced;
376 
377  do {
378  reduced = 0;
379 
380  for (i = 0; i < graph->filter_count; i++)
381  reduced |= reduce_formats_on_filter(graph->filters[i]);
382  } while (reduced);
383 }
384 
386 {
387  AVFilterLink *link = NULL;
388  int sample_rate;
389  int i, j;
390 
391  for (i = 0; i < filter->nb_inputs; i++) {
392  link = filter->inputs[i];
393 
394  if (link->type == AVMEDIA_TYPE_AUDIO &&
395  link->out_samplerates->format_count == 1)
396  break;
397  }
398  if (i == filter->nb_inputs)
399  return;
400 
401  sample_rate = link->out_samplerates->formats[0];
402 
403  for (i = 0; i < filter->nb_outputs; i++) {
404  AVFilterLink *outlink = filter->outputs[i];
405  int best_idx, best_diff = INT_MAX;
406 
407  if (outlink->type != AVMEDIA_TYPE_AUDIO ||
408  outlink->in_samplerates->format_count < 2)
409  continue;
410 
411  for (j = 0; j < outlink->in_samplerates->format_count; j++) {
412  int diff = abs(sample_rate - outlink->in_samplerates->formats[j]);
413 
414  if (diff < best_diff) {
415  best_diff = diff;
416  best_idx = j;
417  }
418  }
419  FFSWAP(int, outlink->in_samplerates->formats[0],
420  outlink->in_samplerates->formats[best_idx]);
421  }
422 }
423 
424 static void swap_samplerates(AVFilterGraph *graph)
425 {
426  int i;
427 
428  for (i = 0; i < graph->filter_count; i++)
430 }
431 
432 #define CH_CENTER_PAIR (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)
433 #define CH_FRONT_PAIR (AV_CH_FRONT_LEFT | AV_CH_FRONT_RIGHT)
434 #define CH_STEREO_PAIR (AV_CH_STEREO_LEFT | AV_CH_STEREO_RIGHT)
435 #define CH_WIDE_PAIR (AV_CH_WIDE_LEFT | AV_CH_WIDE_RIGHT)
436 #define CH_SIDE_PAIR (AV_CH_SIDE_LEFT | AV_CH_SIDE_RIGHT)
437 #define CH_DIRECT_PAIR (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT)
438 #define CH_BACK_PAIR (AV_CH_BACK_LEFT | AV_CH_BACK_RIGHT)
439 
440 /* allowable substitutions for channel pairs when comparing layouts,
441  * ordered by priority for both values */
442 static const uint64_t ch_subst[][2] = {
464 };
465 
467 {
468  AVFilterLink *link = NULL;
469  int i, j, k;
470 
471  for (i = 0; i < filter->nb_inputs; i++) {
472  link = filter->inputs[i];
473 
474  if (link->type == AVMEDIA_TYPE_AUDIO &&
476  break;
477  }
478  if (i == filter->nb_inputs)
479  return;
480 
481  for (i = 0; i < filter->nb_outputs; i++) {
482  AVFilterLink *outlink = filter->outputs[i];
483  int best_idx = -1, best_score = INT_MIN, best_count_diff = INT_MAX;
484 
485  if (outlink->type != AVMEDIA_TYPE_AUDIO ||
487  continue;
488 
489  for (j = 0; j < outlink->in_channel_layouts->nb_channel_layouts; j++) {
490  uint64_t in_chlayout = link->out_channel_layouts->channel_layouts[0];
491  uint64_t out_chlayout = outlink->in_channel_layouts->channel_layouts[j];
492  int in_channels = av_get_channel_layout_nb_channels(in_chlayout);
493  int out_channels = av_get_channel_layout_nb_channels(out_chlayout);
494  int count_diff = out_channels - in_channels;
495  int matched_channels, extra_channels;
496  int score = 0;
497 
498  /* channel substitution */
499  for (k = 0; k < FF_ARRAY_ELEMS(ch_subst); k++) {
500  uint64_t cmp0 = ch_subst[k][0];
501  uint64_t cmp1 = ch_subst[k][1];
502  if (( in_chlayout & cmp0) && (!(out_chlayout & cmp0)) &&
503  (out_chlayout & cmp1) && (!( in_chlayout & cmp1))) {
504  in_chlayout &= ~cmp0;
505  out_chlayout &= ~cmp1;
506  /* add score for channel match, minus a deduction for
507  having to do the substitution */
508  score += 10 * av_get_channel_layout_nb_channels(cmp1) - 2;
509  }
510  }
511 
512  /* no penalty for LFE channel mismatch */
513  if ( (in_chlayout & AV_CH_LOW_FREQUENCY) &&
514  (out_chlayout & AV_CH_LOW_FREQUENCY))
515  score += 10;
516  in_chlayout &= ~AV_CH_LOW_FREQUENCY;
517  out_chlayout &= ~AV_CH_LOW_FREQUENCY;
518 
519  matched_channels = av_get_channel_layout_nb_channels(in_chlayout &
520  out_chlayout);
521  extra_channels = av_get_channel_layout_nb_channels(out_chlayout &
522  (~in_chlayout));
523  score += 10 * matched_channels - 5 * extra_channels;
524 
525  if (score > best_score ||
526  (count_diff < best_count_diff && score == best_score)) {
527  best_score = score;
528  best_idx = j;
529  best_count_diff = count_diff;
530  }
531  }
532  av_assert0(best_idx >= 0);
533  FFSWAP(uint64_t, outlink->in_channel_layouts->channel_layouts[0],
534  outlink->in_channel_layouts->channel_layouts[best_idx]);
535  }
536 
537 }
538 
540 {
541  int i;
542 
543  for (i = 0; i < graph->filter_count; i++)
545 }
546 
548 {
549  AVFilterLink *link = NULL;
550  int format, bps;
551  int i, j;
552 
553  for (i = 0; i < filter->nb_inputs; i++) {
554  link = filter->inputs[i];
555 
556  if (link->type == AVMEDIA_TYPE_AUDIO &&
557  link->out_formats->format_count == 1)
558  break;
559  }
560  if (i == filter->nb_inputs)
561  return;
562 
563  format = link->out_formats->formats[0];
564  bps = av_get_bytes_per_sample(format);
565 
566  for (i = 0; i < filter->nb_outputs; i++) {
567  AVFilterLink *outlink = filter->outputs[i];
568  int best_idx = -1, best_score = INT_MIN;
569 
570  if (outlink->type != AVMEDIA_TYPE_AUDIO ||
571  outlink->in_formats->format_count < 2)
572  continue;
573 
574  for (j = 0; j < outlink->in_formats->format_count; j++) {
575  int out_format = outlink->in_formats->formats[j];
576  int out_bps = av_get_bytes_per_sample(out_format);
577  int score;
578 
579  if (av_get_packed_sample_fmt(out_format) == format ||
580  av_get_planar_sample_fmt(out_format) == format) {
581  best_idx = j;
582  break;
583  }
584 
585  /* for s32 and float prefer double to prevent loss of information */
586  if (bps == 4 && out_bps == 8) {
587  best_idx = j;
588  break;
589  }
590 
591  /* prefer closest higher or equal bps */
592  score = -abs(out_bps - bps);
593  if (out_bps >= bps)
594  score += INT_MAX/2;
595 
596  if (score > best_score) {
597  best_score = score;
598  best_idx = j;
599  }
600  }
601  av_assert0(best_idx >= 0);
602  FFSWAP(int, outlink->in_formats->formats[0],
603  outlink->in_formats->formats[best_idx]);
604  }
605 }
606 
607 static void swap_sample_fmts(AVFilterGraph *graph)
608 {
609  int i;
610 
611  for (i = 0; i < graph->filter_count; i++)
613 
614 }
615 
616 static int pick_formats(AVFilterGraph *graph)
617 {
618  int i, j, ret;
619 
620  for (i = 0; i < graph->filter_count; i++) {
621  AVFilterContext *filter = graph->filters[i];
622 
623  for (j = 0; j < filter->nb_inputs; j++)
624  if ((ret = pick_format(filter->inputs[j])) < 0)
625  return ret;
626  for (j = 0; j < filter->nb_outputs; j++)
627  if ((ret = pick_format(filter->outputs[j])) < 0)
628  return ret;
629  }
630  return 0;
631 }
632 
636 static int graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
637 {
638  int ret;
639 
640  /* find supported formats from sub-filters, and merge along links */
641  if ((ret = query_formats(graph, log_ctx)) < 0)
642  return ret;
643 
644  /* Once everything is merged, it's possible that we'll still have
645  * multiple valid media format choices. We try to minimize the amount
646  * of format conversion inside filters */
647  reduce_formats(graph);
648 
649  /* for audio filters, ensure the best format, sample rate and channel layout
650  * is selected */
651  swap_sample_fmts(graph);
652  swap_samplerates(graph);
653  swap_channel_layouts(graph);
654 
655  if ((ret = pick_formats(graph)) < 0)
656  return ret;
657 
658  return 0;
659 }
660 
661 static int graph_insert_fifos(AVFilterGraph *graph, AVClass *log_ctx)
662 {
663  AVFilterContext *f;
664  int i, j, ret;
665  int fifo_count = 0;
666 
667  for (i = 0; i < graph->filter_count; i++) {
668  f = graph->filters[i];
669 
670  for (j = 0; j < f->nb_inputs; j++) {
671  AVFilterLink *link = f->inputs[j];
672  AVFilterContext *fifo_ctx;
673  AVFilter *fifo;
674  char name[32];
675 
676  if (!link->dstpad->needs_fifo)
677  continue;
678 
679  fifo = f->inputs[j]->type == AVMEDIA_TYPE_VIDEO ?
680  avfilter_get_by_name("fifo") :
681  avfilter_get_by_name("afifo");
682 
683  snprintf(name, sizeof(name), "auto-inserted fifo %d", fifo_count++);
684 
685  ret = avfilter_graph_create_filter(&fifo_ctx, fifo, name, NULL,
686  NULL, graph);
687  if (ret < 0)
688  return ret;
689 
690  ret = avfilter_insert_filter(link, fifo_ctx, 0, 0);
691  if (ret < 0)
692  return ret;
693  }
694  }
695 
696  return 0;
697 }
698 
699 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
700 {
701  int ret;
702 
703  if ((ret = graph_check_validity(graphctx, log_ctx)))
704  return ret;
705  if ((ret = graph_insert_fifos(graphctx, log_ctx)) < 0)
706  return ret;
707  if ((ret = graph_config_formats(graphctx, log_ctx)))
708  return ret;
709  if ((ret = graph_config_links(graphctx, log_ctx)))
710  return ret;
711 
712  return 0;
713 }