lavfi: add channel layout/sample rate negotiation.
[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/log.h"
33
34 static const AVClass filtergraph_class = {
35     .class_name = "AVFilterGraph",
36     .item_name  = av_default_item_name,
37     .version    = LIBAVUTIL_VERSION_INT,
38 };
39
40 AVFilterGraph *avfilter_graph_alloc(void)
41 {
42     AVFilterGraph *ret = av_mallocz(sizeof(AVFilterGraph));
43     if (!ret)
44         return NULL;
45 #if FF_API_GRAPH_AVCLASS
46     ret->av_class = &filtergraph_class;
47 #endif
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 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
97 {
98     AVFilterContext *filt;
99     int i, j;
100
101     for (i = 0; i < graph->filter_count; i++) {
102         filt = graph->filters[i];
103
104         for (j = 0; j < filt->input_count; j++) {
105             if (!filt->inputs[j] || !filt->inputs[j]->src) {
106                 av_log(log_ctx, AV_LOG_ERROR,
107                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
108                        filt->input_pads[j].name, filt->name, filt->filter->name);
109                 return AVERROR(EINVAL);
110             }
111         }
112
113         for (j = 0; j < filt->output_count; j++) {
114             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
115                 av_log(log_ctx, AV_LOG_ERROR,
116                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
117                        filt->output_pads[j].name, filt->name, filt->filter->name);
118                 return AVERROR(EINVAL);
119             }
120         }
121     }
122
123     return 0;
124 }
125
126 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
127 {
128     AVFilterContext *filt;
129     int i, ret;
130
131     for (i=0; i < graph->filter_count; i++) {
132         filt = graph->filters[i];
133
134         if (!filt->output_count) {
135             if ((ret = avfilter_config_links(filt)))
136                 return ret;
137         }
138     }
139
140     return 0;
141 }
142
143 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
144 {
145     int i;
146
147     for (i = 0; i < graph->filter_count; i++)
148         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
149             return graph->filters[i];
150
151     return NULL;
152 }
153
154 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
155 {
156     int i, j, ret;
157     int scaler_count = 0, resampler_count = 0;
158
159     /* ask all the sub-filters for their supported media formats */
160     for (i = 0; i < graph->filter_count; i++) {
161         if (graph->filters[i]->filter->query_formats)
162             graph->filters[i]->filter->query_formats(graph->filters[i]);
163         else
164             avfilter_default_query_formats(graph->filters[i]);
165     }
166
167     /* go through and merge as many format lists as possible */
168     for (i = 0; i < graph->filter_count; i++) {
169         AVFilterContext *filter = graph->filters[i];
170
171         for (j = 0; j < filter->input_count; j++) {
172             AVFilterLink *link = filter->inputs[j];
173             int convert_needed = 0;
174
175             if (!link)
176                 continue;
177
178             if (link->in_formats != link->out_formats &&
179                 !avfilter_merge_formats(link->in_formats,
180                                         link->out_formats))
181                 convert_needed = 1;
182             if (link->type == AVMEDIA_TYPE_AUDIO) {
183                 if (link->in_channel_layouts != link->out_channel_layouts &&
184                     !ff_merge_channel_layouts(link->in_channel_layouts,
185                                               link->out_channel_layouts))
186                     convert_needed = 1;
187                 if (link->in_samplerates != link->out_samplerates &&
188                     !ff_merge_samplerates(link->in_samplerates,
189                                           link->out_samplerates))
190                     convert_needed = 1;
191             }
192
193             if (convert_needed) {
194                     AVFilterContext *convert;
195                     AVFilter *filter;
196                     AVFilterLink *inlink, *outlink;
197                     char scale_args[256];
198                     char inst_name[30];
199
200                     /* couldn't merge format lists. auto-insert conversion filter */
201                     switch (link->type) {
202                     case AVMEDIA_TYPE_VIDEO:
203                         snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
204                                  scaler_count++);
205                         snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
206                         if ((ret = avfilter_graph_create_filter(&convert,
207                                                                 avfilter_get_by_name("scale"),
208                                                                 inst_name, scale_args, NULL,
209                                                                 graph)) < 0)
210                             return ret;
211                         break;
212                     case AVMEDIA_TYPE_AUDIO:
213                         if (!(filter = avfilter_get_by_name("resample"))) {
214                             av_log(log_ctx, AV_LOG_ERROR, "'resample' filter "
215                                    "not present, cannot convert audio formats.\n");
216                             return AVERROR(EINVAL);
217                         }
218
219                         snprintf(inst_name, sizeof(inst_name), "auto-inserted resampler %d",
220                                  resampler_count++);
221                         if ((ret = avfilter_graph_create_filter(&convert,
222                                                                 avfilter_get_by_name("resample"),
223                                                                 inst_name, NULL, NULL, graph)) < 0)
224                             return ret;
225                         break;
226                     default:
227                         return AVERROR(EINVAL);
228                     }
229
230                     if ((ret = avfilter_insert_filter(link, convert, 0, 0)) < 0)
231                         return ret;
232
233                     convert->filter->query_formats(convert);
234                     inlink  = convert->inputs[0];
235                     outlink = convert->outputs[0];
236                     if (!avfilter_merge_formats( inlink->in_formats,  inlink->out_formats) ||
237                         !avfilter_merge_formats(outlink->in_formats, outlink->out_formats))
238                         ret |= AVERROR(ENOSYS);
239                     if (inlink->type == AVMEDIA_TYPE_AUDIO &&
240                         (!ff_merge_samplerates(inlink->in_samplerates,
241                                                inlink->out_samplerates) ||
242                          !ff_merge_channel_layouts(inlink->in_channel_layouts,
243                                                    inlink->out_channel_layouts)))
244                         ret |= AVERROR(ENOSYS);
245                     if (outlink->type == AVMEDIA_TYPE_AUDIO &&
246                         (!ff_merge_samplerates(outlink->in_samplerates,
247                                                outlink->out_samplerates) ||
248                          !ff_merge_channel_layouts(outlink->in_channel_layouts,
249                                                    outlink->out_channel_layouts)))
250                         ret |= AVERROR(ENOSYS);
251
252                     if (ret < 0) {
253                         av_log(log_ctx, AV_LOG_ERROR,
254                                "Impossible to convert between the formats supported by the filter "
255                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
256                         return ret;
257                     }
258             }
259         }
260     }
261
262     return 0;
263 }
264
265 static int pick_format(AVFilterLink *link)
266 {
267     if (!link || !link->in_formats)
268         return 0;
269
270     link->in_formats->format_count = 1;
271     link->format = link->in_formats->formats[0];
272
273     if (link->type == AVMEDIA_TYPE_AUDIO) {
274         if (!link->in_samplerates->format_count) {
275             av_log(link->src, AV_LOG_ERROR, "Cannot select sample rate for"
276                    " the link between filters %s and %s.\n", link->src->name,
277                    link->dst->name);
278             return AVERROR(EINVAL);
279         }
280         link->in_samplerates->format_count = 1;
281         link->sample_rate = link->in_samplerates->formats[0];
282
283         if (!link->in_channel_layouts->nb_channel_layouts) {
284             av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout for"
285                    "the link between filters %s and %s.\n", link->src->name,
286                    link->dst->name);
287             return AVERROR(EINVAL);
288         }
289         link->in_channel_layouts->nb_channel_layouts = 1;
290         link->channel_layout = link->in_channel_layouts->channel_layouts[0];
291     }
292
293     avfilter_formats_unref(&link->in_formats);
294     avfilter_formats_unref(&link->out_formats);
295     avfilter_formats_unref(&link->in_samplerates);
296     avfilter_formats_unref(&link->out_samplerates);
297     ff_channel_layouts_unref(&link->in_channel_layouts);
298     ff_channel_layouts_unref(&link->out_channel_layouts);
299
300     return 0;
301 }
302
303 #define REDUCE_FORMATS(fmt_type, list_type, list, var, nb, add_format) \
304 do {                                                                   \
305     for (i = 0; i < filter->input_count; i++) {                        \
306         AVFilterLink *link = filter->inputs[i];                        \
307         fmt_type fmt;                                                  \
308                                                                        \
309         if (!link->out_ ## list || link->out_ ## list->nb != 1)        \
310             continue;                                                  \
311         fmt = link->out_ ## list->var[0];                              \
312                                                                        \
313         for (j = 0; j < filter->output_count; j++) {                   \
314             AVFilterLink *out_link = filter->outputs[j];               \
315             list_type *fmts;                                           \
316                                                                        \
317             if (link->type != out_link->type ||                        \
318                 out_link->in_ ## list->nb == 1)                        \
319                 continue;                                              \
320             fmts = out_link->in_ ## list;                              \
321                                                                        \
322             if (!out_link->in_ ## list->nb) {                          \
323                 add_format(&out_link->in_ ##list, fmt);                \
324                 break;                                                 \
325             }                                                          \
326                                                                        \
327             for (k = 0; k < out_link->in_ ## list->nb; k++)            \
328                 if (fmts->var[k] == fmt) {                             \
329                     fmts->var[0]  = fmt;                               \
330                     fmts->nb = 1;                                      \
331                     ret = 1;                                           \
332                     break;                                             \
333                 }                                                      \
334         }                                                              \
335     }                                                                  \
336 } while (0)
337
338 static int reduce_formats_on_filter(AVFilterContext *filter)
339 {
340     int i, j, k, ret = 0;
341
342     REDUCE_FORMATS(int,      AVFilterFormats,        formats,         formats,
343                    format_count, avfilter_add_format);
344     REDUCE_FORMATS(int,      AVFilterFormats,        samplerates,     formats,
345                    format_count, avfilter_add_format);
346     REDUCE_FORMATS(uint64_t, AVFilterChannelLayouts, channel_layouts,
347                    channel_layouts, nb_channel_layouts, ff_add_channel_layout);
348
349     return ret;
350 }
351
352 static void reduce_formats(AVFilterGraph *graph)
353 {
354     int i, reduced;
355
356     do {
357         reduced = 0;
358
359         for (i = 0; i < graph->filter_count; i++)
360             reduced |= reduce_formats_on_filter(graph->filters[i]);
361     } while (reduced);
362 }
363
364 static void swap_samplerates_on_filter(AVFilterContext *filter)
365 {
366     AVFilterLink *link = NULL;
367     int sample_rate;
368     int i, j;
369
370     for (i = 0; i < filter->input_count; i++) {
371         link = filter->inputs[i];
372
373         if (link->type == AVMEDIA_TYPE_AUDIO &&
374             link->out_samplerates->format_count == 1)
375             break;
376     }
377     if (i == filter->input_count)
378         return;
379
380     sample_rate = link->out_samplerates->formats[0];
381
382     for (i = 0; i < filter->output_count; i++) {
383         AVFilterLink *outlink = filter->outputs[i];
384         int best_idx, best_diff = INT_MAX;
385
386         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
387             outlink->in_samplerates->format_count < 2)
388             continue;
389
390         for (j = 0; j < outlink->in_samplerates->format_count; j++) {
391             int diff = abs(sample_rate - outlink->in_samplerates->formats[j]);
392
393             if (diff < best_diff) {
394                 best_diff = diff;
395                 best_idx  = j;
396             }
397         }
398         FFSWAP(int, outlink->in_samplerates->formats[0],
399                outlink->in_samplerates->formats[best_idx]);
400     }
401 }
402
403 static void swap_samplerates(AVFilterGraph *graph)
404 {
405     int i;
406
407     for (i = 0; i < graph->filter_count; i++)
408         swap_samplerates_on_filter(graph->filters[i]);
409 }
410
411 static void swap_channel_layouts_on_filter(AVFilterContext *filter)
412 {
413     AVFilterLink *link = NULL;
414     uint64_t chlayout;
415     int i, j;
416
417     for (i = 0; i < filter->input_count; i++) {
418         link = filter->inputs[i];
419
420         if (link->type == AVMEDIA_TYPE_AUDIO &&
421             link->out_channel_layouts->nb_channel_layouts == 1)
422             break;
423     }
424     if (i == filter->input_count)
425         return;
426
427     chlayout = link->out_channel_layouts->channel_layouts[0];
428
429     for (i = 0; i < filter->output_count; i++) {
430         AVFilterLink *outlink = filter->outputs[i];
431         int best_idx, best_score = INT_MIN;
432
433         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
434             outlink->in_channel_layouts->nb_channel_layouts < 2)
435             continue;
436
437         for (j = 0; j < outlink->in_channel_layouts->nb_channel_layouts; j++) {
438             uint64_t out_chlayout = outlink->in_channel_layouts->channel_layouts[j];
439             int matched_channels  = av_get_channel_layout_nb_channels(chlayout &
440                                                                       out_chlayout);
441             int extra_channels     = av_get_channel_layout_nb_channels(out_chlayout &
442                                                                        (~chlayout));
443             int score = matched_channels - extra_channels;
444
445             if (score > best_score) {
446                 best_score = score;
447                 best_idx   = j;
448             }
449         }
450         FFSWAP(uint64_t, outlink->in_channel_layouts->channel_layouts[0],
451                outlink->in_channel_layouts->channel_layouts[best_idx]);
452     }
453
454 }
455
456 static void swap_channel_layouts(AVFilterGraph *graph)
457 {
458     int i;
459
460     for (i = 0; i < graph->filter_count; i++)
461         swap_channel_layouts_on_filter(graph->filters[i]);
462 }
463
464 static int pick_formats(AVFilterGraph *graph)
465 {
466     int i, j, ret;
467
468     for (i = 0; i < graph->filter_count; i++) {
469         AVFilterContext *filter = graph->filters[i];
470
471         for (j = 0; j < filter->input_count; j++)
472             if ((ret = pick_format(filter->inputs[j])) < 0)
473                 return ret;
474         for (j = 0; j < filter->output_count; j++)
475             if ((ret = pick_format(filter->outputs[j])) < 0)
476                 return ret;
477     }
478     return 0;
479 }
480
481 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
482 {
483     int ret;
484
485     /* find supported formats from sub-filters, and merge along links */
486     if ((ret = query_formats(graph, log_ctx)) < 0)
487         return ret;
488
489     /* Once everything is merged, it's possible that we'll still have
490      * multiple valid media format choices. We try to minimize the amount
491      * of format conversion inside filters */
492     reduce_formats(graph);
493
494     /* for audio filters, ensure the best sample rate and channel layout
495      * is selected */
496     swap_samplerates(graph);
497     swap_channel_layouts(graph);
498
499     if ((ret = pick_formats(graph)) < 0)
500         return ret;
501
502     return 0;
503 }
504
505 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)
506 {
507     int ret;
508
509     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))
510         return ret;
511     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))
512         return ret;
513     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))
514         return ret;
515
516     return 0;
517 }