avfiltergraph: check for sws opts being non-NULL before using them.
[ffmpeg.git] / 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 <string.h>
24
25 #include "libavutil/avassert.h"
26 #include "libavutil/avstring.h"
27 #include "libavutil/channel_layout.h"
28 #include "libavutil/common.h"
29 #include "libavutil/log.h"
30 #include "avfilter.h"
31 #include "avfiltergraph.h"
32 #include "formats.h"
33 #include "internal.h"
34
35 static const AVClass filtergraph_class = {
36     .class_name = "AVFilterGraph",
37     .item_name  = av_default_item_name,
38     .version    = LIBAVUTIL_VERSION_INT,
39 };
40
41 AVFilterGraph *avfilter_graph_alloc(void)
42 {
43     AVFilterGraph *ret = av_mallocz(sizeof(*ret));
44     if (!ret)
45         return NULL;
46     ret->av_class = &filtergraph_class;
47     return ret;
48 }
49
50 void avfilter_graph_free(AVFilterGraph **graph)
51 {
52     if (!*graph)
53         return;
54     for (; (*graph)->nb_filters > 0; (*graph)->nb_filters--)
55         avfilter_free((*graph)->filters[(*graph)->nb_filters - 1]);
56     av_freep(&(*graph)->scale_sws_opts);
57     av_freep(&(*graph)->resample_lavr_opts);
58     av_freep(&(*graph)->filters);
59     av_freep(graph);
60 }
61
62 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
63 {
64     AVFilterContext **filters = av_realloc(graph->filters,
65                                            sizeof(*filters) * (graph->nb_filters + 1));
66     if (!filters)
67         return AVERROR(ENOMEM);
68
69     graph->filters = filters;
70     graph->filters[graph->nb_filters++] = filter;
71
72     return 0;
73 }
74
75 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
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
96 /**
97  * Check for the validity of graph.
98  *
99  * A graph is considered valid if all its input and output pads are
100  * connected.
101  *
102  * @return 0 in case of success, a negative value otherwise
103  */
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->nb_filters; 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
134 /**
135  * Configure all the links of graphctx.
136  *
137  * @return 0 in case of success, a negative value otherwise
138  */
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->nb_filters; 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
156 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
157 {
158     int i;
159
160     for (i = 0; i < graph->nb_filters; 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->nb_filters; i++) {
174         if (graph->filters[i]->filter->query_formats)
175             graph->filters[i]->filter->query_formats(graph->filters[i]);
176         else
177             ff_default_query_formats(graph->filters[i]);
178     }
179
180     /* go through and merge as many format lists as possible */
181     for (i = 0; i < graph->nb_filters; 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 &&
192                 !ff_merge_formats(link->in_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 &&
197                     !ff_merge_channel_layouts(link->in_channel_layouts,
198                                               link->out_channel_layouts))
199                     convert_needed = 1;
200                 if (link->in_samplerates != link->out_samplerates &&
201                     !ff_merge_samplerates(link->in_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                     scale_args[0] = '\0';
244                     if (graph->resample_lavr_opts)
245                         snprintf(scale_args, sizeof(scale_args), "%s",
246                                  graph->resample_lavr_opts);
247                     if ((ret = avfilter_graph_create_filter(&convert, filter,
248                                                             inst_name, scale_args,
249                                                             NULL, graph)) < 0)
250                         return ret;
251                     break;
252                 default:
253                     return AVERROR(EINVAL);
254                 }
255
256                 if ((ret = avfilter_insert_filter(link, convert, 0, 0)) < 0)
257                     return ret;
258
259                 convert->filter->query_formats(convert);
260                 inlink  = convert->inputs[0];
261                 outlink = convert->outputs[0];
262                 if (!ff_merge_formats( inlink->in_formats,  inlink->out_formats) ||
263                     !ff_merge_formats(outlink->in_formats, outlink->out_formats))
264                     ret |= AVERROR(ENOSYS);
265                 if (inlink->type == AVMEDIA_TYPE_AUDIO &&
266                     (!ff_merge_samplerates(inlink->in_samplerates,
267                                            inlink->out_samplerates) ||
268                      !ff_merge_channel_layouts(inlink->in_channel_layouts,
269                                                inlink->out_channel_layouts)))
270                     ret |= AVERROR(ENOSYS);
271                 if (outlink->type == AVMEDIA_TYPE_AUDIO &&
272                     (!ff_merge_samplerates(outlink->in_samplerates,
273                                            outlink->out_samplerates) ||
274                      !ff_merge_channel_layouts(outlink->in_channel_layouts,
275                                                outlink->out_channel_layouts)))
276                     ret |= AVERROR(ENOSYS);
277
278                 if (ret < 0) {
279                     av_log(log_ctx, AV_LOG_ERROR,
280                            "Impossible to convert between the formats supported by the filter "
281                            "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
282                     return ret;
283                 }
284             }
285         }
286     }
287
288     return 0;
289 }
290
291 static int pick_format(AVFilterLink *link)
292 {
293     if (!link || !link->in_formats)
294         return 0;
295
296     link->in_formats->format_count = 1;
297     link->format = link->in_formats->formats[0];
298
299     if (link->type == AVMEDIA_TYPE_AUDIO) {
300         if (!link->in_samplerates->format_count) {
301             av_log(link->src, AV_LOG_ERROR, "Cannot select sample rate for"
302                    " the link between filters %s and %s.\n", link->src->name,
303                    link->dst->name);
304             return AVERROR(EINVAL);
305         }
306         link->in_samplerates->format_count = 1;
307         link->sample_rate = link->in_samplerates->formats[0];
308
309         if (!link->in_channel_layouts->nb_channel_layouts) {
310             av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout for"
311                    "the link between filters %s and %s.\n", link->src->name,
312                    link->dst->name);
313             return AVERROR(EINVAL);
314         }
315         link->in_channel_layouts->nb_channel_layouts = 1;
316         link->channel_layout = link->in_channel_layouts->channel_layouts[0];
317     }
318
319     ff_formats_unref(&link->in_formats);
320     ff_formats_unref(&link->out_formats);
321     ff_formats_unref(&link->in_samplerates);
322     ff_formats_unref(&link->out_samplerates);
323     ff_channel_layouts_unref(&link->in_channel_layouts);
324     ff_channel_layouts_unref(&link->out_channel_layouts);
325
326     return 0;
327 }
328
329 #define REDUCE_FORMATS(fmt_type, list_type, list, var, nb, add_format) \
330 do {                                                                   \
331     for (i = 0; i < filter->nb_inputs; i++) {                          \
332         AVFilterLink *link = filter->inputs[i];                        \
333         fmt_type fmt;                                                  \
334                                                                        \
335         if (!link->out_ ## list || link->out_ ## list->nb != 1)        \
336             continue;                                                  \
337         fmt = link->out_ ## list->var[0];                              \
338                                                                        \
339         for (j = 0; j < filter->nb_outputs; j++) {                     \
340             AVFilterLink *out_link = filter->outputs[j];               \
341             list_type *fmts;                                           \
342                                                                        \
343             if (link->type != out_link->type ||                        \
344                 out_link->in_ ## list->nb == 1)                        \
345                 continue;                                              \
346             fmts = out_link->in_ ## list;                              \
347                                                                        \
348             if (!out_link->in_ ## list->nb) {                          \
349                 add_format(&out_link->in_ ##list, fmt);                \
350                 break;                                                 \
351             }                                                          \
352                                                                        \
353             for (k = 0; k < out_link->in_ ## list->nb; k++)            \
354                 if (fmts->var[k] == fmt) {                             \
355                     fmts->var[0]  = fmt;                               \
356                     fmts->nb = 1;                                      \
357                     ret = 1;                                           \
358                     break;                                             \
359                 }                                                      \
360         }                                                              \
361     }                                                                  \
362 } while (0)
363
364 static int reduce_formats_on_filter(AVFilterContext *filter)
365 {
366     int i, j, k, ret = 0;
367
368     REDUCE_FORMATS(int,      AVFilterFormats,        formats,         formats,
369                    format_count, ff_add_format);
370     REDUCE_FORMATS(int,      AVFilterFormats,        samplerates,     formats,
371                    format_count, ff_add_format);
372     REDUCE_FORMATS(uint64_t, AVFilterChannelLayouts, channel_layouts,
373                    channel_layouts, nb_channel_layouts, ff_add_channel_layout);
374
375     return ret;
376 }
377
378 static void reduce_formats(AVFilterGraph *graph)
379 {
380     int i, reduced;
381
382     do {
383         reduced = 0;
384
385         for (i = 0; i < graph->nb_filters; i++)
386             reduced |= reduce_formats_on_filter(graph->filters[i]);
387     } while (reduced);
388 }
389
390 static void swap_samplerates_on_filter(AVFilterContext *filter)
391 {
392     AVFilterLink *link = NULL;
393     int sample_rate;
394     int i, j;
395
396     for (i = 0; i < filter->nb_inputs; i++) {
397         link = filter->inputs[i];
398
399         if (link->type == AVMEDIA_TYPE_AUDIO &&
400             link->out_samplerates->format_count == 1)
401             break;
402     }
403     if (i == filter->nb_inputs)
404         return;
405
406     sample_rate = link->out_samplerates->formats[0];
407
408     for (i = 0; i < filter->nb_outputs; i++) {
409         AVFilterLink *outlink = filter->outputs[i];
410         int best_idx, best_diff = INT_MAX;
411
412         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
413             outlink->in_samplerates->format_count < 2)
414             continue;
415
416         for (j = 0; j < outlink->in_samplerates->format_count; j++) {
417             int diff = abs(sample_rate - outlink->in_samplerates->formats[j]);
418
419             if (diff < best_diff) {
420                 best_diff = diff;
421                 best_idx  = j;
422             }
423         }
424         FFSWAP(int, outlink->in_samplerates->formats[0],
425                outlink->in_samplerates->formats[best_idx]);
426     }
427 }
428
429 static void swap_samplerates(AVFilterGraph *graph)
430 {
431     int i;
432
433     for (i = 0; i < graph->nb_filters; i++)
434         swap_samplerates_on_filter(graph->filters[i]);
435 }
436
437 #define CH_CENTER_PAIR (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)
438 #define CH_FRONT_PAIR  (AV_CH_FRONT_LEFT           | AV_CH_FRONT_RIGHT)
439 #define CH_STEREO_PAIR (AV_CH_STEREO_LEFT          | AV_CH_STEREO_RIGHT)
440 #define CH_WIDE_PAIR   (AV_CH_WIDE_LEFT            | AV_CH_WIDE_RIGHT)
441 #define CH_SIDE_PAIR   (AV_CH_SIDE_LEFT            | AV_CH_SIDE_RIGHT)
442 #define CH_DIRECT_PAIR (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT)
443 #define CH_BACK_PAIR   (AV_CH_BACK_LEFT            | AV_CH_BACK_RIGHT)
444
445 /* allowable substitutions for channel pairs when comparing layouts,
446  * ordered by priority for both values */
447 static const uint64_t ch_subst[][2] = {
448     { CH_FRONT_PAIR,      CH_CENTER_PAIR     },
449     { CH_FRONT_PAIR,      CH_WIDE_PAIR       },
450     { CH_FRONT_PAIR,      AV_CH_FRONT_CENTER },
451     { CH_CENTER_PAIR,     CH_FRONT_PAIR      },
452     { CH_CENTER_PAIR,     CH_WIDE_PAIR       },
453     { CH_CENTER_PAIR,     AV_CH_FRONT_CENTER },
454     { CH_WIDE_PAIR,       CH_FRONT_PAIR      },
455     { CH_WIDE_PAIR,       CH_CENTER_PAIR     },
456     { CH_WIDE_PAIR,       AV_CH_FRONT_CENTER },
457     { AV_CH_FRONT_CENTER, CH_FRONT_PAIR      },
458     { AV_CH_FRONT_CENTER, CH_CENTER_PAIR     },
459     { AV_CH_FRONT_CENTER, CH_WIDE_PAIR       },
460     { CH_SIDE_PAIR,       CH_DIRECT_PAIR     },
461     { CH_SIDE_PAIR,       CH_BACK_PAIR       },
462     { CH_SIDE_PAIR,       AV_CH_BACK_CENTER  },
463     { CH_BACK_PAIR,       CH_DIRECT_PAIR     },
464     { CH_BACK_PAIR,       CH_SIDE_PAIR       },
465     { CH_BACK_PAIR,       AV_CH_BACK_CENTER  },
466     { AV_CH_BACK_CENTER,  CH_BACK_PAIR       },
467     { AV_CH_BACK_CENTER,  CH_DIRECT_PAIR     },
468     { AV_CH_BACK_CENTER,  CH_SIDE_PAIR       },
469 };
470
471 static void swap_channel_layouts_on_filter(AVFilterContext *filter)
472 {
473     AVFilterLink *link = NULL;
474     int i, j, k;
475
476     for (i = 0; i < filter->nb_inputs; i++) {
477         link = filter->inputs[i];
478
479         if (link->type == AVMEDIA_TYPE_AUDIO &&
480             link->out_channel_layouts->nb_channel_layouts == 1)
481             break;
482     }
483     if (i == filter->nb_inputs)
484         return;
485
486     for (i = 0; i < filter->nb_outputs; i++) {
487         AVFilterLink *outlink = filter->outputs[i];
488         int best_idx = -1, best_score = INT_MIN, best_count_diff = INT_MAX;
489
490         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
491             outlink->in_channel_layouts->nb_channel_layouts < 2)
492             continue;
493
494         for (j = 0; j < outlink->in_channel_layouts->nb_channel_layouts; j++) {
495             uint64_t  in_chlayout = link->out_channel_layouts->channel_layouts[0];
496             uint64_t out_chlayout = outlink->in_channel_layouts->channel_layouts[j];
497             int  in_channels      = av_get_channel_layout_nb_channels(in_chlayout);
498             int out_channels      = av_get_channel_layout_nb_channels(out_chlayout);
499             int count_diff        = out_channels - in_channels;
500             int matched_channels, extra_channels;
501             int score = 0;
502
503             /* channel substitution */
504             for (k = 0; k < FF_ARRAY_ELEMS(ch_subst); k++) {
505                 uint64_t cmp0 = ch_subst[k][0];
506                 uint64_t cmp1 = ch_subst[k][1];
507                 if (( in_chlayout & cmp0) && (!(out_chlayout & cmp0)) &&
508                     (out_chlayout & cmp1) && (!( in_chlayout & cmp1))) {
509                     in_chlayout  &= ~cmp0;
510                     out_chlayout &= ~cmp1;
511                     /* add score for channel match, minus a deduction for
512                        having to do the substitution */
513                     score += 10 * av_get_channel_layout_nb_channels(cmp1) - 2;
514                 }
515             }
516
517             /* no penalty for LFE channel mismatch */
518             if ( (in_chlayout & AV_CH_LOW_FREQUENCY) &&
519                 (out_chlayout & AV_CH_LOW_FREQUENCY))
520                 score += 10;
521             in_chlayout  &= ~AV_CH_LOW_FREQUENCY;
522             out_chlayout &= ~AV_CH_LOW_FREQUENCY;
523
524             matched_channels = av_get_channel_layout_nb_channels(in_chlayout &
525                                                                  out_chlayout);
526             extra_channels   = av_get_channel_layout_nb_channels(out_chlayout &
527                                                                  (~in_chlayout));
528             score += 10 * matched_channels - 5 * extra_channels;
529
530             if (score > best_score ||
531                 (count_diff < best_count_diff && score == best_score)) {
532                 best_score = score;
533                 best_idx   = j;
534                 best_count_diff = count_diff;
535             }
536         }
537         av_assert0(best_idx >= 0);
538         FFSWAP(uint64_t, outlink->in_channel_layouts->channel_layouts[0],
539                outlink->in_channel_layouts->channel_layouts[best_idx]);
540     }
541
542 }
543
544 static void swap_channel_layouts(AVFilterGraph *graph)
545 {
546     int i;
547
548     for (i = 0; i < graph->nb_filters; i++)
549         swap_channel_layouts_on_filter(graph->filters[i]);
550 }
551
552 static void swap_sample_fmts_on_filter(AVFilterContext *filter)
553 {
554     AVFilterLink *link = NULL;
555     int format, bps;
556     int i, j;
557
558     for (i = 0; i < filter->nb_inputs; i++) {
559         link = filter->inputs[i];
560
561         if (link->type == AVMEDIA_TYPE_AUDIO &&
562             link->out_formats->format_count == 1)
563             break;
564     }
565     if (i == filter->nb_inputs)
566         return;
567
568     format = link->out_formats->formats[0];
569     bps    = av_get_bytes_per_sample(format);
570
571     for (i = 0; i < filter->nb_outputs; i++) {
572         AVFilterLink *outlink = filter->outputs[i];
573         int best_idx = -1, best_score = INT_MIN;
574
575         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
576             outlink->in_formats->format_count < 2)
577             continue;
578
579         for (j = 0; j < outlink->in_formats->format_count; j++) {
580             int out_format = outlink->in_formats->formats[j];
581             int out_bps    = av_get_bytes_per_sample(out_format);
582             int score;
583
584             if (av_get_packed_sample_fmt(out_format) == format ||
585                 av_get_planar_sample_fmt(out_format) == format) {
586                 best_idx   = j;
587                 break;
588             }
589
590             /* for s32 and float prefer double to prevent loss of information */
591             if (bps == 4 && out_bps == 8) {
592                 best_idx = j;
593                 break;
594             }
595
596             /* prefer closest higher or equal bps */
597             score = -abs(out_bps - bps);
598             if (out_bps >= bps)
599                 score += INT_MAX/2;
600
601             if (score > best_score) {
602                 best_score = score;
603                 best_idx   = j;
604             }
605         }
606         av_assert0(best_idx >= 0);
607         FFSWAP(int, outlink->in_formats->formats[0],
608                outlink->in_formats->formats[best_idx]);
609     }
610 }
611
612 static void swap_sample_fmts(AVFilterGraph *graph)
613 {
614     int i;
615
616     for (i = 0; i < graph->nb_filters; i++)
617         swap_sample_fmts_on_filter(graph->filters[i]);
618
619 }
620
621 static int pick_formats(AVFilterGraph *graph)
622 {
623     int i, j, ret;
624
625     for (i = 0; i < graph->nb_filters; i++) {
626         AVFilterContext *filter = graph->filters[i];
627
628         for (j = 0; j < filter->nb_inputs; j++)
629             if ((ret = pick_format(filter->inputs[j])) < 0)
630                 return ret;
631         for (j = 0; j < filter->nb_outputs; j++)
632             if ((ret = pick_format(filter->outputs[j])) < 0)
633                 return ret;
634     }
635     return 0;
636 }
637
638 /**
639  * Configure the formats of all the links in the graph.
640  */
641 static int graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
642 {
643     int ret;
644
645     /* find supported formats from sub-filters, and merge along links */
646     if ((ret = query_formats(graph, log_ctx)) < 0)
647         return ret;
648
649     /* Once everything is merged, it's possible that we'll still have
650      * multiple valid media format choices. We try to minimize the amount
651      * of format conversion inside filters */
652     reduce_formats(graph);
653
654     /* for audio filters, ensure the best format, sample rate and channel layout
655      * is selected */
656     swap_sample_fmts(graph);
657     swap_samplerates(graph);
658     swap_channel_layouts(graph);
659
660     if ((ret = pick_formats(graph)) < 0)
661         return ret;
662
663     return 0;
664 }
665
666 static int graph_insert_fifos(AVFilterGraph *graph, AVClass *log_ctx)
667 {
668     AVFilterContext *f;
669     int i, j, ret;
670     int fifo_count = 0;
671
672     for (i = 0; i < graph->nb_filters; i++) {
673         f = graph->filters[i];
674
675         for (j = 0; j < f->nb_inputs; j++) {
676             AVFilterLink *link = f->inputs[j];
677             AVFilterContext *fifo_ctx;
678             AVFilter *fifo;
679             char name[32];
680
681             if (!link->dstpad->needs_fifo)
682                 continue;
683
684             fifo = f->inputs[j]->type == AVMEDIA_TYPE_VIDEO ?
685                    avfilter_get_by_name("fifo") :
686                    avfilter_get_by_name("afifo");
687
688             snprintf(name, sizeof(name), "auto-inserted fifo %d", fifo_count++);
689
690             ret = avfilter_graph_create_filter(&fifo_ctx, fifo, name, NULL,
691                                                NULL, graph);
692             if (ret < 0)
693                 return ret;
694
695             ret = avfilter_insert_filter(link, fifo_ctx, 0, 0);
696             if (ret < 0)
697                 return ret;
698         }
699     }
700
701     return 0;
702 }
703
704 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
705 {
706     int ret;
707
708     if ((ret = graph_check_validity(graphctx, log_ctx)))
709         return ret;
710     if ((ret = graph_insert_fifos(graphctx, log_ctx)) < 0)
711         return ret;
712     if ((ret = graph_config_formats(graphctx, log_ctx)))
713         return ret;
714     if ((ret = graph_config_links(graphctx, log_ctx)))
715         return ret;
716
717     return 0;
718 }