h264_metadata: Add option to delete filler data
[libav.git] / libavfilter / graphparser.c
1 /*
2 * filter graph parser
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 #include <stdio.h>
25
26 #include "libavutil/avstring.h"
27 #include "libavutil/mem.h"
28 #include "avfilter.h"
29
30 #define WHITESPACES " \n\t"
31
32 /**
33 * Link two filters together.
34 *
35 * @see avfilter_link()
36 */
37 static int link_filter(AVFilterContext *src, int srcpad,
38 AVFilterContext *dst, int dstpad,
39 void *log_ctx)
40 {
41 int ret;
42 if ((ret = avfilter_link(src, srcpad, dst, dstpad))) {
43 av_log(log_ctx, AV_LOG_ERROR,
44 "Cannot create the link %s:%d -> %s:%d\n",
45 src->filter->name, srcpad, dst->filter->name, dstpad);
46 return ret;
47 }
48
49 return 0;
50 }
51
52 /**
53 * Parse the name of a link, which has the format "[linkname]".
54 *
55 * @return a pointer (that need to be freed after use) to the name
56 * between parenthesis
57 */
58 static char *parse_link_name(const char **buf, void *log_ctx)
59 {
60 const char *start = *buf;
61 char *name;
62 (*buf)++;
63
64 name = av_get_token(buf, "]");
65 if (!name)
66 goto fail;
67
68 if (!name[0]) {
69 av_log(log_ctx, AV_LOG_ERROR,
70 "Bad (empty?) label found in the following: \"%s\".\n", start);
71 goto fail;
72 }
73
74 if (*(*buf)++ != ']') {
75 av_log(log_ctx, AV_LOG_ERROR,
76 "Mismatched '[' found in the following: \"%s\".\n", start);
77 fail:
78 av_freep(&name);
79 }
80
81 return name;
82 }
83
84 #define TMP_ARGS_SIZE 256
85
86 static void append_sws_flags(const char **args, const char *sws_opts, char *tmp)
87 {
88 int nb_opts = 0;
89 const char *separator = ":";
90 const char *opt = *args;
91
92 if (strstr(*args, "flags"))
93 return;
94
95 if (strstr(*args, "="))
96 separator = ":flags=";
97
98 while ((opt = strstr(opt, ":")) && *opt) {
99 av_log(NULL, AV_LOG_INFO, "opts '%s' \n", opt);
100 if (nb_opts > 2) {
101 return;
102 }
103 nb_opts++;
104 opt++;
105 }
106
107 opt = strstr(sws_opts, "flags=");
108 if (opt && strlen(opt) > 6)
109 opt += 6;
110 else
111 opt = sws_opts;
112
113 snprintf(tmp, TMP_ARGS_SIZE, "%s%s%s",
114 *args, separator, opt);
115
116 *args = tmp;
117 }
118
119 /**
120 * Create an instance of a filter, initialize and insert it in the
121 * filtergraph in *ctx.
122 *
123 * @param filt_ctx put here a filter context in case of successful creation and configuration, NULL otherwise.
124 * @param ctx the filtergraph context
125 * @param index an index which is supposed to be unique for each filter instance added to the filtergraph
126 * @param filt_name the name of the filter to create
127 * @param args the arguments provided to the filter during its initialization
128 * @param log_ctx the log context to use
129 * @return 0 in case of success, a negative AVERROR code otherwise
130 */
131 static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index,
132 const char *filt_name, const char *args, void *log_ctx)
133 {
134 const AVFilter *filt;
135 char inst_name[30];
136 char tmp_args[TMP_ARGS_SIZE];
137 int ret;
138
139 snprintf(inst_name, sizeof(inst_name), "Parsed filter %d %s", index, filt_name);
140
141 filt = avfilter_get_by_name(filt_name);
142
143 if (!filt) {
144 av_log(log_ctx, AV_LOG_ERROR,
145 "No such filter: '%s'\n", filt_name);
146 return AVERROR(EINVAL);
147 }
148
149 *filt_ctx = avfilter_graph_alloc_filter(ctx, filt, inst_name);
150 if (!*filt_ctx) {
151 av_log(log_ctx, AV_LOG_ERROR,
152 "Error creating filter '%s'\n", filt_name);
153 return AVERROR(ENOMEM);
154 }
155
156 if (!strcmp(filt_name, "scale") && args &&
157 ctx->scale_sws_opts) {
158 append_sws_flags(&args, ctx->scale_sws_opts, tmp_args);
159 }
160
161 ret = avfilter_init_str(*filt_ctx, args);
162 if (ret < 0) {
163 av_log(log_ctx, AV_LOG_ERROR,
164 "Error initializing filter '%s'", filt_name);
165 if (args)
166 av_log(log_ctx, AV_LOG_ERROR, " with args '%s'", args);
167 av_log(log_ctx, AV_LOG_ERROR, "\n");
168 avfilter_free(*filt_ctx);
169 return ret;
170 }
171
172 return 0;
173 }
174
175 /**
176 * Parse a string of the form FILTER_NAME[=PARAMS], and create a
177 * corresponding filter instance which is added to graph with
178 * create_filter().
179 *
180 * @param filt_ctx Pointer that is set to the created and configured filter
181 * context on success, set to NULL on failure.
182 * @param filt_ctx put here a pointer to the created filter context on
183 * success, NULL otherwise
184 * @param buf pointer to the buffer to parse, *buf will be updated to
185 * point to the char next after the parsed string
186 * @param index an index which is assigned to the created filter
187 * instance, and which is supposed to be unique for each filter
188 * instance added to the filtergraph
189 * @return 0 in case of success, a negative AVERROR code otherwise
190 */
191 static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
192 int index, void *log_ctx)
193 {
194 char *opts = NULL;
195 char *name = av_get_token(buf, "=,;[\n");
196 int ret;
197
198 if (**buf == '=') {
199 (*buf)++;
200 opts = av_get_token(buf, "[],;\n");
201 }
202
203 ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
204 av_free(name);
205 av_free(opts);
206 return ret;
207 }
208
209 AVFilterInOut *avfilter_inout_alloc(void)
210 {
211 return av_mallocz(sizeof(AVFilterInOut));
212 }
213
214 void avfilter_inout_free(AVFilterInOut **inout)
215 {
216 while (*inout) {
217 AVFilterInOut *next = (*inout)->next;
218 av_freep(&(*inout)->name);
219 av_freep(inout);
220 *inout = next;
221 }
222 }
223
224 static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
225 {
226 AVFilterInOut *ret;
227
228 while (*links && (!(*links)->name || strcmp((*links)->name, label)))
229 links = &((*links)->next);
230
231 ret = *links;
232
233 if (ret) {
234 *links = ret->next;
235 ret->next = NULL;
236 }
237
238 return ret;
239 }
240
241 static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
242 {
243 element->next = *inouts;
244 *inouts = element;
245 }
246
247 static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
248 {
249 while (*inouts && (*inouts)->next)
250 inouts = &((*inouts)->next);
251
252 if (!*inouts)
253 *inouts = *element;
254 else
255 (*inouts)->next = *element;
256 *element = NULL;
257 }
258
259 static int link_filter_inouts(AVFilterContext *filt_ctx,
260 AVFilterInOut **curr_inputs,
261 AVFilterInOut **open_inputs, void *log_ctx)
262 {
263 int pad, ret;
264
265 for (pad = 0; pad < filt_ctx->nb_inputs; pad++) {
266 AVFilterInOut *p = *curr_inputs;
267
268 if (p) {
269 *curr_inputs = (*curr_inputs)->next;
270 p->next = NULL;
271 } else if (!(p = av_mallocz(sizeof(*p))))
272 return AVERROR(ENOMEM);
273
274 if (p->filter_ctx) {
275 ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx);
276 av_free(p->name);
277 av_free(p);
278 if (ret < 0)
279 return ret;
280 } else {
281 p->filter_ctx = filt_ctx;
282 p->pad_idx = pad;
283 append_inout(open_inputs, &p);
284 }
285 }
286
287 if (*curr_inputs) {
288 av_log(log_ctx, AV_LOG_ERROR,
289 "Too many inputs specified for the \"%s\" filter.\n",
290 filt_ctx->filter->name);
291 return AVERROR(EINVAL);
292 }
293
294 pad = filt_ctx->nb_outputs;
295 while (pad--) {
296 AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
297 if (!currlinkn)
298 return AVERROR(ENOMEM);
299 currlinkn->filter_ctx = filt_ctx;
300 currlinkn->pad_idx = pad;
301 insert_inout(curr_inputs, currlinkn);
302 }
303
304 return 0;
305 }
306
307 static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
308 AVFilterInOut **open_outputs, void *log_ctx)
309 {
310 AVFilterInOut *parsed_inputs = NULL;
311 int pad = 0;
312
313 while (**buf == '[') {
314 char *name = parse_link_name(buf, log_ctx);
315 AVFilterInOut *match;
316
317 if (!name)
318 return AVERROR(EINVAL);
319
320 /* First check if the label is not in the open_outputs list */
321 match = extract_inout(name, open_outputs);
322
323 if (match) {
324 av_free(name);
325 } else {
326 /* Not in the list, so add it as an input */
327 if (!(match = av_mallocz(sizeof(AVFilterInOut)))) {
328 av_free(name);
329 return AVERROR(ENOMEM);
330 }
331 match->name = name;
332 match->pad_idx = pad;
333 }
334
335 append_inout(&parsed_inputs, &match);
336
337 *buf += strspn(*buf, WHITESPACES);
338 pad++;
339 }
340
341 append_inout(&parsed_inputs, curr_inputs);
342 *curr_inputs = parsed_inputs;
343
344 return pad;
345 }
346
347 static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
348 AVFilterInOut **open_inputs,
349 AVFilterInOut **open_outputs, void *log_ctx)
350 {
351 int ret, pad = 0;
352
353 while (**buf == '[') {
354 char *name = parse_link_name(buf, log_ctx);
355 AVFilterInOut *match;
356
357 AVFilterInOut *input = *curr_inputs;
358
359 if (!name)
360 return AVERROR(EINVAL);
361
362 if (!input) {
363 av_log(log_ctx, AV_LOG_ERROR,
364 "No output pad can be associated to link label '%s'.\n", name);
365 av_free(name);
366 return AVERROR(EINVAL);
367 }
368 *curr_inputs = (*curr_inputs)->next;
369
370 /* First check if the label is not in the open_inputs list */
371 match = extract_inout(name, open_inputs);
372
373 if (match) {
374 if ((ret = link_filter(input->filter_ctx, input->pad_idx,
375 match->filter_ctx, match->pad_idx, log_ctx)) < 0) {
376 av_free(name);
377 return ret;
378 }
379 av_free(match->name);
380 av_free(name);
381 av_free(match);
382 av_free(input);
383 } else {
384 /* Not in the list, so add the first input as a open_output */
385 input->name = name;
386 insert_inout(open_outputs, input);
387 }
388 *buf += strspn(*buf, WHITESPACES);
389 pad++;
390 }
391
392 return pad;
393 }
394
395 static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
396 {
397 char *p = strchr(*buf, ';');
398
399 if (strncmp(*buf, "sws_flags=", 10))
400 return 0;
401
402 if (!p) {
403 av_log(graph, AV_LOG_ERROR, "sws_flags not terminated with ';'.\n");
404 return AVERROR(EINVAL);
405 }
406
407 *buf += 4; // keep the 'flags=' part
408
409 av_freep(&graph->scale_sws_opts);
410 if (!(graph->scale_sws_opts = av_mallocz(p - *buf + 1)))
411 return AVERROR(ENOMEM);
412 av_strlcpy(graph->scale_sws_opts, *buf, p - *buf + 1);
413
414 *buf = p + 1;
415 return 0;
416 }
417
418 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
419 AVFilterInOut **inputs,
420 AVFilterInOut **outputs)
421 {
422 int index = 0, ret;
423 char chr = 0;
424
425 AVFilterInOut *curr_inputs = NULL, *open_inputs = NULL, *open_outputs = NULL;
426
427 filters += strspn(filters, WHITESPACES);
428
429 if ((ret = parse_sws_flags(&filters, graph)) < 0)
430 goto fail;
431
432 do {
433 AVFilterContext *filter;
434 filters += strspn(filters, WHITESPACES);
435
436 if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, graph)) < 0)
437 goto fail;
438
439 if ((ret = parse_filter(&filter, &filters, graph, index, graph)) < 0)
440 goto fail;
441
442
443 if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, graph)) < 0)
444 goto fail;
445
446 if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
447 graph)) < 0)
448 goto fail;
449
450 filters += strspn(filters, WHITESPACES);
451 chr = *filters++;
452
453 if (chr == ';' && curr_inputs)
454 append_inout(&open_outputs, &curr_inputs);
455 index++;
456 } while (chr == ',' || chr == ';');
457
458 if (chr) {
459 av_log(graph, AV_LOG_ERROR,
460 "Unable to parse graph description substring: \"%s\"\n",
461 filters - 1);
462 ret = AVERROR(EINVAL);
463 goto fail;
464 }
465
466 append_inout(&open_outputs, &curr_inputs);
467
468 *inputs = open_inputs;
469 *outputs = open_outputs;
470 return 0;
471
472 fail:
473 while (graph->nb_filters)
474 avfilter_free(graph->filters[0]);
475 av_freep(&graph->filters);
476 avfilter_inout_free(&open_inputs);
477 avfilter_inout_free(&open_outputs);
478 avfilter_inout_free(&curr_inputs);
479
480 *inputs = NULL;
481 *outputs = NULL;
482
483 return ret;
484 }
485
486 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
487 AVFilterInOut *open_inputs,
488 AVFilterInOut *open_outputs, void *log_ctx)
489 {
490 int ret;
491 AVFilterInOut *cur, *match, *inputs = NULL, *outputs = NULL;
492
493 if ((ret = avfilter_graph_parse2(graph, filters, &inputs, &outputs)) < 0)
494 goto fail;
495
496 /* First input can be omitted if it is "[in]" */
497 if (inputs && !inputs->name)
498 inputs->name = av_strdup("in");
499 for (cur = inputs; cur; cur = cur->next) {
500 if (!cur->name) {
501 av_log(log_ctx, AV_LOG_ERROR,
502 "Not enough inputs specified for the \"%s\" filter.\n",
503 cur->filter_ctx->filter->name);
504 ret = AVERROR(EINVAL);
505 goto fail;
506 }
507 if (!(match = extract_inout(cur->name, &open_outputs)))
508 continue;
509 ret = avfilter_link(match->filter_ctx, match->pad_idx,
510 cur->filter_ctx, cur->pad_idx);
511 avfilter_inout_free(&match);
512 if (ret < 0)
513 goto fail;
514 }
515
516 /* Last output can be omitted if it is "[out]" */
517 if (outputs && !outputs->name)
518 outputs->name = av_strdup("out");
519 for (cur = outputs; cur; cur = cur->next) {
520 if (!cur->name) {
521 av_log(log_ctx, AV_LOG_ERROR,
522 "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
523 filters);
524 ret = AVERROR(EINVAL);
525 goto fail;
526 }
527 if (!(match = extract_inout(cur->name, &open_inputs)))
528 continue;
529 ret = avfilter_link(cur->filter_ctx, cur->pad_idx,
530 match->filter_ctx, match->pad_idx);
531 avfilter_inout_free(&match);
532 if (ret < 0)
533 goto fail;
534 }
535
536 fail:
537 if (ret < 0) {
538 while (graph->nb_filters)
539 avfilter_free(graph->filters[0]);
540 av_freep(&graph->filters);
541 }
542 avfilter_inout_free(&inputs);
543 avfilter_inout_free(&outputs);
544 avfilter_inout_free(&open_inputs);
545 avfilter_inout_free(&open_outputs);
546 return ret;
547 }