4a66c7842ad43ba70c34bbb529d5611dd472c541
[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 <ctype.h>
24 #include <string.h>
25
26 #include "avfilter.h"
27 #include "avfiltergraph.h"
28 #include "formats.h"
29 #include "internal.h"
30
31 #include "libavutil/audioconvert.h"
32 #include "libavutil/avassert.h"
33 #include "libavutil/common.h"
34 #include "libavutil/log.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
42 AVFilterGraph *avfilter_graph_alloc(void)
43 {
44     AVFilterGraph *ret = av_mallocz(sizeof(AVFilterGraph));
45     if (!ret)
46         return NULL;
47     ret->av_class = &filtergraph_class;
48     return ret;
49 }
50
51 void avfilter_graph_free(AVFilterGraph **graph)
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
62 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
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
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->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
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->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
156 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
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
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->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 &&
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                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
225                     if ((ret = avfilter_graph_create_filter(&convert, filter,
226                                                             inst_name, scale_args, NULL,
227                                                             graph)) < 0)
228                         return ret;
229                     break;
230                 case AVMEDIA_TYPE_AUDIO:
231                     if (!(filter = avfilter_get_by_name("resample"))) {
232                         av_log(log_ctx, AV_LOG_ERROR, "'resample' filter "
233                                "not present, cannot convert audio formats.\n");
234                         return AVERROR(EINVAL);
235                     }
236
237                     snprintf(inst_name, sizeof(inst_name), "auto-inserted resampler %d",
238                              resampler_count++);
239                     if ((ret = avfilter_graph_create_filter(&convert, filter,
240                                                             inst_name, NULL, NULL, graph)) < 0)
241                         return ret;
242                     break;
243                 default:
244                     return AVERROR(EINVAL);
245                 }
246
247                 if ((ret = avfilter_insert_filter(link, convert, 0, 0)) < 0)
248                     return ret;
249
250                 convert->filter->query_formats(convert);
251                 inlink  = convert->inputs[0];
252                 outlink = convert->outputs[0];
253                 if (!ff_merge_formats( inlink->in_formats,  inlink->out_formats) ||
254                     !ff_merge_formats(outlink->in_formats, outlink->out_formats))
255                     ret |= AVERROR(ENOSYS);
256                 if (inlink->type == AVMEDIA_TYPE_AUDIO &&
257                     (!ff_merge_samplerates(inlink->in_samplerates,
258                                            inlink->out_samplerates) ||
259                      !ff_merge_channel_layouts(inlink->in_channel_layouts,
260                                                inlink->out_channel_layouts)))
261                     ret |= AVERROR(ENOSYS);
262                 if (outlink->type == AVMEDIA_TYPE_AUDIO &&
263                     (!ff_merge_samplerates(outlink->in_samplerates,
264                                            outlink->out_samplerates) ||
265                      !ff_merge_channel_layouts(outlink->in_channel_layouts,
266                                                outlink->out_channel_layouts)))
267                     ret |= AVERROR(ENOSYS);
268
269                 if (ret < 0) {
270                     av_log(log_ctx, AV_LOG_ERROR,
271                            "Impossible to convert between the formats supported by the filter "
272                            "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
273                     return ret;
274                 }
275             }
276         }
277     }
278
279     return 0;
280 }
281
282 static int pick_format(AVFilterLink *link)
283 {
284     if (!link || !link->in_formats)
285         return 0;
286
287     link->in_formats->format_count = 1;
288     link->format = link->in_formats->formats[0];
289
290     if (link->type == AVMEDIA_TYPE_AUDIO) {
291         if (!link->in_samplerates->format_count) {
292             av_log(link->src, AV_LOG_ERROR, "Cannot select sample rate for"
293                    " the link between filters %s and %s.\n", link->src->name,
294                    link->dst->name);
295             return AVERROR(EINVAL);
296         }
297         link->in_samplerates->format_count = 1;
298         link->sample_rate = link->in_samplerates->formats[0];
299
300         if (!link->in_channel_layouts->nb_channel_layouts) {
301             av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout 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_channel_layouts->nb_channel_layouts = 1;
307         link->channel_layout = link->in_channel_layouts->channel_layouts[0];
308     }
309
310     ff_formats_unref(&link->in_formats);
311     ff_formats_unref(&link->out_formats);
312     ff_formats_unref(&link->in_samplerates);
313     ff_formats_unref(&link->out_samplerates);
314     ff_channel_layouts_unref(&link->in_channel_layouts);
315     ff_channel_layouts_unref(&link->out_channel_layouts);
316
317     return 0;
318 }
319
320 #define REDUCE_FORMATS(fmt_type, list_type, list, var, nb, add_format) \
321 do {                                                                   \
322     for (i = 0; i < filter->nb_inputs; i++) {                          \
323         AVFilterLink *link = filter->inputs[i];                        \
324         fmt_type fmt;                                                  \
325                                                                        \
326         if (!link->out_ ## list || link->out_ ## list->nb != 1)        \
327             continue;                                                  \
328         fmt = link->out_ ## list->var[0];                              \
329                                                                        \
330         for (j = 0; j < filter->nb_outputs; j++) {                     \
331             AVFilterLink *out_link = filter->outputs[j];               \
332             list_type *fmts;                                           \
333                                                                        \
334             if (link->type != out_link->type ||                        \
335                 out_link->in_ ## list->nb == 1)                        \
336                 continue;                                              \
337             fmts = out_link->in_ ## list;                              \
338                                                                        \
339             if (!out_link->in_ ## list->nb) {                          \
340                 add_format(&out_link->in_ ##list, fmt);                \
341                 break;                                                 \
342             }                                                          \
343                                                                        \
344             for (k = 0; k < out_link->in_ ## list->nb; k++)            \
345                 if (fmts->var[k] == fmt) {                             \
346                     fmts->var[0]  = fmt;                               \
347                     fmts->nb = 1;                                      \
348                     ret = 1;                                           \
349                     break;                                             \
350                 }                                                      \
351         }                                                              \
352     }                                                                  \
353 } while (0)
354
355 static int reduce_formats_on_filter(AVFilterContext *filter)
356 {
357     int i, j, k, ret = 0;
358
359     REDUCE_FORMATS(int,      AVFilterFormats,        formats,         formats,
360                    format_count, ff_add_format);
361     REDUCE_FORMATS(int,      AVFilterFormats,        samplerates,     formats,
362                    format_count, ff_add_format);
363     REDUCE_FORMATS(uint64_t, AVFilterChannelLayouts, channel_layouts,
364                    channel_layouts, nb_channel_layouts, ff_add_channel_layout);
365
366     return ret;
367 }
368
369 static void reduce_formats(AVFilterGraph *graph)
370 {
371     int i, reduced;
372
373     do {
374         reduced = 0;
375
376         for (i = 0; i < graph->filter_count; i++)
377             reduced |= reduce_formats_on_filter(graph->filters[i]);
378     } while (reduced);
379 }
380
381 static void swap_samplerates_on_filter(AVFilterContext *filter)
382 {
383     AVFilterLink *link = NULL;
384     int sample_rate;
385     int i, j;
386
387     for (i = 0; i < filter->nb_inputs; i++) {
388         link = filter->inputs[i];
389
390         if (link->type == AVMEDIA_TYPE_AUDIO &&
391             link->out_samplerates->format_count == 1)
392             break;
393     }
394     if (i == filter->nb_inputs)
395         return;
396
397     sample_rate = link->out_samplerates->formats[0];
398
399     for (i = 0; i < filter->nb_outputs; i++) {
400         AVFilterLink *outlink = filter->outputs[i];
401         int best_idx, best_diff = INT_MAX;
402
403         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
404             outlink->in_samplerates->format_count < 2)
405             continue;
406
407         for (j = 0; j < outlink->in_samplerates->format_count; j++) {
408             int diff = abs(sample_rate - outlink->in_samplerates->formats[j]);
409
410             if (diff < best_diff) {
411                 best_diff = diff;
412                 best_idx  = j;
413             }
414         }
415         FFSWAP(int, outlink->in_samplerates->formats[0],
416                outlink->in_samplerates->formats[best_idx]);
417     }
418 }
419
420 static void swap_samplerates(AVFilterGraph *graph)
421 {
422     int i;
423
424     for (i = 0; i < graph->filter_count; i++)
425         swap_samplerates_on_filter(graph->filters[i]);
426 }
427
428 #define CH_CENTER_PAIR (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)
429 #define CH_FRONT_PAIR  (AV_CH_FRONT_LEFT           | AV_CH_FRONT_RIGHT)
430 #define CH_STEREO_PAIR (AV_CH_STEREO_LEFT          | AV_CH_STEREO_RIGHT)
431 #define CH_WIDE_PAIR   (AV_CH_WIDE_LEFT            | AV_CH_WIDE_RIGHT)
432 #define CH_SIDE_PAIR   (AV_CH_SIDE_LEFT            | AV_CH_SIDE_RIGHT)
433 #define CH_DIRECT_PAIR (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT)
434 #define CH_BACK_PAIR   (AV_CH_BACK_LEFT            | AV_CH_BACK_RIGHT)
435
436 /* allowable substitutions for channel pairs when comparing layouts,
437  * ordered by priority for both values */
438 static const uint64_t ch_subst[][2] = {
439     { CH_FRONT_PAIR,      CH_CENTER_PAIR     },
440     { CH_FRONT_PAIR,      CH_WIDE_PAIR       },
441     { CH_FRONT_PAIR,      AV_CH_FRONT_CENTER },
442     { CH_CENTER_PAIR,     CH_FRONT_PAIR      },
443     { CH_CENTER_PAIR,     CH_WIDE_PAIR       },
444     { CH_CENTER_PAIR,     AV_CH_FRONT_CENTER },
445     { CH_WIDE_PAIR,       CH_FRONT_PAIR      },
446     { CH_WIDE_PAIR,       CH_CENTER_PAIR     },
447     { CH_WIDE_PAIR,       AV_CH_FRONT_CENTER },
448     { AV_CH_FRONT_CENTER, CH_FRONT_PAIR      },
449     { AV_CH_FRONT_CENTER, CH_CENTER_PAIR     },
450     { AV_CH_FRONT_CENTER, CH_WIDE_PAIR       },
451     { CH_SIDE_PAIR,       CH_DIRECT_PAIR     },
452     { CH_SIDE_PAIR,       CH_BACK_PAIR       },
453     { CH_SIDE_PAIR,       AV_CH_BACK_CENTER  },
454     { CH_BACK_PAIR,       CH_DIRECT_PAIR     },
455     { CH_BACK_PAIR,       CH_SIDE_PAIR       },
456     { CH_BACK_PAIR,       AV_CH_BACK_CENTER  },
457     { AV_CH_BACK_CENTER,  CH_BACK_PAIR       },
458     { AV_CH_BACK_CENTER,  CH_DIRECT_PAIR     },
459     { AV_CH_BACK_CENTER,  CH_SIDE_PAIR       },
460 };
461
462 static void swap_channel_layouts_on_filter(AVFilterContext *filter)
463 {
464     AVFilterLink *link = NULL;
465     int i, j, k;
466
467     for (i = 0; i < filter->nb_inputs; i++) {
468         link = filter->inputs[i];
469
470         if (link->type == AVMEDIA_TYPE_AUDIO &&
471             link->out_channel_layouts->nb_channel_layouts == 1)
472             break;
473     }
474     if (i == filter->nb_inputs)
475         return;
476
477     for (i = 0; i < filter->nb_outputs; i++) {
478         AVFilterLink *outlink = filter->outputs[i];
479         int best_idx = -1, best_score = INT_MIN, best_count_diff = INT_MAX;
480
481         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
482             outlink->in_channel_layouts->nb_channel_layouts < 2)
483             continue;
484
485         for (j = 0; j < outlink->in_channel_layouts->nb_channel_layouts; j++) {
486             uint64_t  in_chlayout = link->out_channel_layouts->channel_layouts[0];
487             uint64_t out_chlayout = outlink->in_channel_layouts->channel_layouts[j];
488             int  in_channels      = av_get_channel_layout_nb_channels(in_chlayout);
489             int out_channels      = av_get_channel_layout_nb_channels(out_chlayout);
490             int count_diff        = out_channels - in_channels;
491             int matched_channels, extra_channels;
492             int score = 0;
493
494             /* channel substitution */
495             for (k = 0; k < FF_ARRAY_ELEMS(ch_subst); k++) {
496                 uint64_t cmp0 = ch_subst[k][0];
497                 uint64_t cmp1 = ch_subst[k][1];
498                 if (( in_chlayout & cmp0) && (!(out_chlayout & cmp0)) &&
499                     (out_chlayout & cmp1) && (!( in_chlayout & cmp1))) {
500                     in_chlayout  &= ~cmp0;
501                     out_chlayout &= ~cmp1;
502                     /* add score for channel match, minus a deduction for
503                        having to do the substitution */
504                     score += 10 * av_get_channel_layout_nb_channels(cmp1) - 2;
505                 }
506             }
507
508             /* no penalty for LFE channel mismatch */
509             if ( (in_chlayout & AV_CH_LOW_FREQUENCY) &&
510                 (out_chlayout & AV_CH_LOW_FREQUENCY))
511                 score += 10;
512             in_chlayout  &= ~AV_CH_LOW_FREQUENCY;
513             out_chlayout &= ~AV_CH_LOW_FREQUENCY;
514
515             matched_channels = av_get_channel_layout_nb_channels(in_chlayout &
516                                                                  out_chlayout);
517             extra_channels   = av_get_channel_layout_nb_channels(out_chlayout &
518                                                                  (~in_chlayout));
519             score += 10 * matched_channels - 5 * extra_channels;
520
521             if (score > best_score ||
522                 (count_diff < best_count_diff && score == best_score)) {
523                 best_score = score;
524                 best_idx   = j;
525                 best_count_diff = count_diff;
526             }
527         }
528         av_assert0(best_idx >= 0);
529         FFSWAP(uint64_t, outlink->in_channel_layouts->channel_layouts[0],
530                outlink->in_channel_layouts->channel_layouts[best_idx]);
531     }
532
533 }
534
535 static void swap_channel_layouts(AVFilterGraph *graph)
536 {
537     int i;
538
539     for (i = 0; i < graph->filter_count; i++)
540         swap_channel_layouts_on_filter(graph->filters[i]);
541 }
542
543 static void swap_sample_fmts_on_filter(AVFilterContext *filter)
544 {
545     AVFilterLink *link = NULL;
546     int format, bps;
547     int i, j;
548
549     for (i = 0; i < filter->nb_inputs; i++) {
550         link = filter->inputs[i];
551
552         if (link->type == AVMEDIA_TYPE_AUDIO &&
553             link->out_formats->format_count == 1)
554             break;
555     }
556     if (i == filter->nb_inputs)
557         return;
558
559     format = link->out_formats->formats[0];
560     bps    = av_get_bytes_per_sample(format);
561
562     for (i = 0; i < filter->nb_outputs; i++) {
563         AVFilterLink *outlink = filter->outputs[i];
564         int best_idx = -1, best_score = INT_MIN;
565
566         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
567             outlink->in_formats->format_count < 2)
568             continue;
569
570         for (j = 0; j < outlink->in_formats->format_count; j++) {
571             int out_format = outlink->in_formats->formats[j];
572             int out_bps    = av_get_bytes_per_sample(out_format);
573             int score;
574
575             if (av_get_packed_sample_fmt(out_format) == format ||
576                 av_get_planar_sample_fmt(out_format) == format) {
577                 best_idx   = j;
578                 break;
579             }
580
581             /* for s32 and float prefer double to prevent loss of information */
582             if (bps == 4 && out_bps == 8) {
583                 best_idx = j;
584                 break;
585             }
586
587             /* prefer closest higher or equal bps */
588             score = -abs(out_bps - bps);
589             if (out_bps >= bps)
590                 score += INT_MAX/2;
591
592             if (score > best_score) {
593                 best_score = score;
594                 best_idx   = j;
595             }
596         }
597         av_assert0(best_idx >= 0);
598         FFSWAP(int, outlink->in_formats->formats[0],
599                outlink->in_formats->formats[best_idx]);
600     }
601 }
602
603 static void swap_sample_fmts(AVFilterGraph *graph)
604 {
605     int i;
606
607     for (i = 0; i < graph->filter_count; i++)
608         swap_sample_fmts_on_filter(graph->filters[i]);
609
610 }
611
612 static int pick_formats(AVFilterGraph *graph)
613 {
614     int i, j, ret;
615
616     for (i = 0; i < graph->filter_count; i++) {
617         AVFilterContext *filter = graph->filters[i];
618
619         for (j = 0; j < filter->nb_inputs; j++)
620             if ((ret = pick_format(filter->inputs[j])) < 0)
621                 return ret;
622         for (j = 0; j < filter->nb_outputs; j++)
623             if ((ret = pick_format(filter->outputs[j])) < 0)
624                 return ret;
625     }
626     return 0;
627 }
628
629 /**
630  * Configure the formats of all the links in the graph.
631  */
632 static int graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
633 {
634     int ret;
635
636     /* find supported formats from sub-filters, and merge along links */
637     if ((ret = query_formats(graph, log_ctx)) < 0)
638         return ret;
639
640     /* Once everything is merged, it's possible that we'll still have
641      * multiple valid media format choices. We try to minimize the amount
642      * of format conversion inside filters */
643     reduce_formats(graph);
644
645     /* for audio filters, ensure the best format, sample rate and channel layout
646      * is selected */
647     swap_sample_fmts(graph);
648     swap_samplerates(graph);
649     swap_channel_layouts(graph);
650
651     if ((ret = pick_formats(graph)) < 0)
652         return ret;
653
654     return 0;
655 }
656
657 static int graph_insert_fifos(AVFilterGraph *graph, AVClass *log_ctx)
658 {
659     AVFilterContext *f;
660     int i, j, ret;
661     int fifo_count = 0;
662
663     for (i = 0; i < graph->filter_count; i++) {
664         f = graph->filters[i];
665
666         for (j = 0; j < f->nb_inputs; j++) {
667             AVFilterLink *link = f->inputs[j];
668             AVFilterContext *fifo_ctx;
669             AVFilter *fifo;
670             char name[32];
671
672             if (!link->dstpad->needs_fifo)
673                 continue;
674
675             fifo = f->inputs[j]->type == AVMEDIA_TYPE_VIDEO ?
676                    avfilter_get_by_name("fifo") :
677                    avfilter_get_by_name("afifo");
678
679             snprintf(name, sizeof(name), "auto-inserted fifo %d", fifo_count++);
680
681             ret = avfilter_graph_create_filter(&fifo_ctx, fifo, name, NULL,
682                                                NULL, graph);
683             if (ret < 0)
684                 return ret;
685
686             ret = avfilter_insert_filter(link, fifo_ctx, 0, 0);
687             if (ret < 0)
688                 return ret;
689         }
690     }
691
692     return 0;
693 }
694
695 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
696 {
697     int ret;
698
699     if ((ret = graph_check_validity(graphctx, log_ctx)))
700         return ret;
701     if ((ret = graph_insert_fifos(graphctx, log_ctx)) < 0)
702         return ret;
703     if ((ret = graph_config_formats(graphctx, log_ctx)))
704         return ret;
705     if ((ret = graph_config_links(graphctx, log_ctx)))
706         return ret;
707
708     return 0;
709 }