3 * Copyright (c) 2008 Vitor Sessak
4 * Copyright (c) 2007 Bobby Bingham
6 * This file is part of FFmpeg.
8 * FFmpeg 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.
13 * FFmpeg 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.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 #include "libavutil/avstring.h"
27 #include "libavutil/mem.h"
29 #include "avfiltergraph.h"
31 #define WHITESPACES " \n\t"
34 * Link two filters together.
36 * @see avfilter_link()
38 static int link_filter(AVFilterContext *src, int srcpad,
39 AVFilterContext *dst, int dstpad,
43 if ((ret = avfilter_link(src, srcpad, dst, dstpad))) {
44 av_log(log_ctx, AV_LOG_ERROR,
45 "Cannot create the link %s:%d -> %s:%d\n",
46 src->filter->name, srcpad, dst->filter->name, dstpad);
54 * Parse the name of a link, which has the format "[linkname]".
56 * @return a pointer (that need to be freed after use) to the name
59 static char *parse_link_name(const char **buf, void *log_ctx)
61 const char *start = *buf;
65 name = av_get_token(buf, "]");
68 av_log(log_ctx, AV_LOG_ERROR,
69 "Bad (empty?) label found in the following: \"%s\".\n", start);
73 if (*(*buf)++ != ']') {
74 av_log(log_ctx, AV_LOG_ERROR,
75 "Mismatched '[' found in the following: \"%s\".\n", start);
84 * Create an instance of a filter, initialize and insert it in the
85 * filtergraph in *ctx.
87 * @param filt_ctx put here a filter context in case of successful creation and configuration, NULL otherwise.
88 * @param ctx the filtergraph context
89 * @param index an index which is supposed to be unique for each filter instance added to the filtergraph
90 * @param filt_name the name of the filter to create
91 * @param args the arguments provided to the filter during its initialization
92 * @param log_ctx the log context to use
93 * @return 0 in case of success, a negative AVERROR code otherwise
95 static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index,
96 const char *filt_name, const char *args, void *log_ctx)
103 snprintf(inst_name, sizeof(inst_name), "Parsed_%s_%d", filt_name, index);
105 filt = avfilter_get_by_name(filt_name);
108 av_log(log_ctx, AV_LOG_ERROR,
109 "No such filter: '%s'\n", filt_name);
110 return AVERROR(EINVAL);
113 ret = avfilter_open(filt_ctx, filt, inst_name);
115 av_log(log_ctx, AV_LOG_ERROR,
116 "Error creating filter '%s'\n", filt_name);
120 if ((ret = avfilter_graph_add_filter(ctx, *filt_ctx)) < 0) {
121 avfilter_free(*filt_ctx);
125 if (!strcmp(filt_name, "scale") && args && !strstr(args, "flags")
126 && ctx->scale_sws_opts) {
127 snprintf(tmp_args, sizeof(tmp_args), "%s:%s",
128 args, ctx->scale_sws_opts);
132 if ((ret = avfilter_init_filter(*filt_ctx, args, NULL)) < 0) {
133 av_log(log_ctx, AV_LOG_ERROR,
134 "Error initializing filter '%s' with args '%s'\n", filt_name, args);
142 * Parse a string of the form FILTER_NAME[=PARAMS], and create a
143 * corresponding filter instance which is added to graph with
146 * @param filt_ctx Pointer that is set to the created and configured filter
147 * context on success, set to NULL on failure.
148 * @param filt_ctx put here a pointer to the created filter context on
149 * success, NULL otherwise
150 * @param buf pointer to the buffer to parse, *buf will be updated to
151 * point to the char next after the parsed string
152 * @param index an index which is assigned to the created filter
153 * instance, and which is supposed to be unique for each filter
154 * instance added to the filtergraph
155 * @return 0 in case of success, a negative AVERROR code otherwise
157 static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
158 int index, void *log_ctx)
161 char *name = av_get_token(buf, "=,;[\n");
166 opts = av_get_token(buf, "[],;\n");
169 ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
175 AVFilterInOut *avfilter_inout_alloc(void)
177 return av_mallocz(sizeof(AVFilterInOut));
180 void avfilter_inout_free(AVFilterInOut **inout)
183 AVFilterInOut *next = (*inout)->next;
184 av_freep(&(*inout)->name);
190 static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
194 while (*links && (!(*links)->name || strcmp((*links)->name, label)))
195 links = &((*links)->next);
207 static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
209 element->next = *inouts;
213 static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
215 while (*inouts && (*inouts)->next)
216 inouts = &((*inouts)->next);
221 (*inouts)->next = *element;
225 static int link_filter_inouts(AVFilterContext *filt_ctx,
226 AVFilterInOut **curr_inputs,
227 AVFilterInOut **open_inputs, void *log_ctx)
231 for (pad = 0; pad < filt_ctx->nb_inputs; pad++) {
232 AVFilterInOut *p = *curr_inputs;
235 *curr_inputs = (*curr_inputs)->next;
237 } else if (!(p = av_mallocz(sizeof(*p))))
238 return AVERROR(ENOMEM);
241 ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx);
247 p->filter_ctx = filt_ctx;
249 append_inout(open_inputs, &p);
254 av_log(log_ctx, AV_LOG_ERROR,
255 "Too many inputs specified for the \"%s\" filter.\n",
256 filt_ctx->filter->name);
257 return AVERROR(EINVAL);
260 pad = filt_ctx->nb_outputs;
262 AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
264 return AVERROR(ENOMEM);
265 currlinkn->filter_ctx = filt_ctx;
266 currlinkn->pad_idx = pad;
267 insert_inout(curr_inputs, currlinkn);
273 static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
274 AVFilterInOut **open_outputs, void *log_ctx)
276 AVFilterInOut *parsed_inputs = NULL;
279 while (**buf == '[') {
280 char *name = parse_link_name(buf, log_ctx);
281 AVFilterInOut *match;
284 return AVERROR(EINVAL);
286 /* First check if the label is not in the open_outputs list */
287 match = extract_inout(name, open_outputs);
292 /* Not in the list, so add it as an input */
293 if (!(match = av_mallocz(sizeof(AVFilterInOut)))) {
295 return AVERROR(ENOMEM);
298 match->pad_idx = pad;
301 append_inout(&parsed_inputs, &match);
303 *buf += strspn(*buf, WHITESPACES);
307 append_inout(&parsed_inputs, curr_inputs);
308 *curr_inputs = parsed_inputs;
313 static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
314 AVFilterInOut **open_inputs,
315 AVFilterInOut **open_outputs, void *log_ctx)
319 while (**buf == '[') {
320 char *name = parse_link_name(buf, log_ctx);
321 AVFilterInOut *match;
323 AVFilterInOut *input = *curr_inputs;
326 return AVERROR(EINVAL);
329 av_log(log_ctx, AV_LOG_ERROR,
330 "No output pad can be associated to link label '%s'.\n", name);
332 return AVERROR(EINVAL);
334 *curr_inputs = (*curr_inputs)->next;
336 /* First check if the label is not in the open_inputs list */
337 match = extract_inout(name, open_inputs);
340 if ((ret = link_filter(input->filter_ctx, input->pad_idx,
341 match->filter_ctx, match->pad_idx, log_ctx)) < 0) {
345 av_free(match->name);
350 /* Not in the list, so add the first input as a open_output */
352 insert_inout(open_outputs, input);
354 *buf += strspn(*buf, WHITESPACES);
361 static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
363 char *p = strchr(*buf, ';');
365 if (strncmp(*buf, "sws_flags=", 10))
369 av_log(graph, AV_LOG_ERROR, "sws_flags not terminated with ';'.\n");
370 return AVERROR(EINVAL);
373 *buf += 4; // keep the 'flags=' part
375 av_freep(&graph->scale_sws_opts);
376 if (!(graph->scale_sws_opts = av_mallocz(p - *buf + 1)))
377 return AVERROR(ENOMEM);
378 av_strlcpy(graph->scale_sws_opts, *buf, p - *buf + 1);
384 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
385 AVFilterInOut **inputs,
386 AVFilterInOut **outputs)
388 int index = 0, ret = 0;
391 AVFilterInOut *curr_inputs = NULL, *open_inputs = NULL, *open_outputs = NULL;
393 filters += strspn(filters, WHITESPACES);
395 if ((ret = parse_sws_flags(&filters, graph)) < 0)
399 AVFilterContext *filter;
400 filters += strspn(filters, WHITESPACES);
402 if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, graph)) < 0)
404 if ((ret = parse_filter(&filter, &filters, graph, index, graph)) < 0)
408 if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, graph)) < 0)
411 if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
415 filters += strspn(filters, WHITESPACES);
418 if (chr == ';' && curr_inputs)
419 append_inout(&open_outputs, &curr_inputs);
421 } while (chr == ',' || chr == ';');
424 av_log(graph, AV_LOG_ERROR,
425 "Unable to parse graph description substring: \"%s\"\n",
427 ret = AVERROR(EINVAL);
431 append_inout(&open_outputs, &curr_inputs);
434 *inputs = open_inputs;
435 *outputs = open_outputs;
439 for (; graph->nb_filters > 0; graph->nb_filters--)
440 avfilter_free(graph->filters[graph->nb_filters - 1]);
441 av_freep(&graph->filters);
442 avfilter_inout_free(&open_inputs);
443 avfilter_inout_free(&open_outputs);
444 avfilter_inout_free(&curr_inputs);
452 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
453 AVFilterInOut **open_inputs_ptr, AVFilterInOut **open_outputs_ptr,
458 AVFilterInOut *open_inputs = open_inputs_ptr ? *open_inputs_ptr : NULL;
459 AVFilterInOut *open_outputs = open_outputs_ptr ? *open_outputs_ptr : NULL;
460 AVFilterInOut *cur, *match, *inputs = NULL, *outputs = NULL;
462 if ((ret = avfilter_graph_parse2(graph, filters, &inputs, &outputs)) < 0)
465 /* First input can be omitted if it is "[in]" */
466 if (inputs && !inputs->name)
467 inputs->name = av_strdup("in");
468 for (cur = inputs; cur; cur = cur->next) {
470 av_log(log_ctx, AV_LOG_ERROR,
471 "Not enough inputs specified for the \"%s\" filter.\n",
472 cur->filter_ctx->filter->name);
473 ret = AVERROR(EINVAL);
476 if (!(match = extract_inout(cur->name, &open_outputs)))
478 ret = avfilter_link(match->filter_ctx, match->pad_idx,
479 cur->filter_ctx, cur->pad_idx);
480 avfilter_inout_free(&match);
485 /* Last output can be omitted if it is "[out]" */
486 if (outputs && !outputs->name)
487 outputs->name = av_strdup("out");
488 for (cur = outputs; cur; cur = cur->next) {
490 av_log(log_ctx, AV_LOG_ERROR,
491 "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
493 ret = AVERROR(EINVAL);
496 if (!(match = extract_inout(cur->name, &open_inputs)))
498 ret = avfilter_link(cur->filter_ctx, cur->pad_idx,
499 match->filter_ctx, match->pad_idx);
500 avfilter_inout_free(&match);
507 for (; graph->nb_filters > 0; graph->nb_filters--)
508 avfilter_free(graph->filters[graph->nb_filters - 1]);
509 av_freep(&graph->filters);
511 avfilter_inout_free(&inputs);
512 avfilter_inout_free(&outputs);
513 /* clear open_in/outputs only if not passed as parameters */
514 if (open_inputs_ptr) *open_inputs_ptr = open_inputs;
515 else avfilter_inout_free(&open_inputs);
516 if (open_outputs_ptr) *open_outputs_ptr = open_outputs;
517 else avfilter_inout_free(&open_outputs);
521 int index = 0, ret = 0;
524 AVFilterInOut *curr_inputs = NULL;
525 AVFilterInOut *open_inputs = open_inputs_ptr ? *open_inputs_ptr : NULL;
526 AVFilterInOut *open_outputs = open_outputs_ptr ? *open_outputs_ptr : NULL;
528 if ((ret = parse_sws_flags(&filters, graph)) < 0)
532 AVFilterContext *filter;
533 const char *filterchain = filters;
534 filters += strspn(filters, WHITESPACES);
536 if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx)) < 0)
539 if ((ret = parse_filter(&filter, &filters, graph, index, log_ctx)) < 0)
542 if (filter->input_count == 1 && !curr_inputs && !index) {
543 /* First input pad, assume it is "[in]" if not specified */
544 const char *tmp = "[in]";
545 if ((ret = parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx)) < 0)
549 if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx)) < 0)
552 if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
556 filters += strspn(filters, WHITESPACES);
559 if (chr == ';' && curr_inputs) {
560 av_log(log_ctx, AV_LOG_ERROR,
561 "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
563 ret = AVERROR(EINVAL);
567 } while (chr == ',' || chr == ';');
570 av_log(log_ctx, AV_LOG_ERROR,
571 "Unable to parse graph description substring: \"%s\"\n",
573 ret = AVERROR(EINVAL);
578 /* Last output pad, assume it is "[out]" if not specified */
579 const char *tmp = "[out]";
580 if ((ret = parse_outputs(&tmp, &curr_inputs, &open_inputs, &open_outputs,
586 /* clear open_in/outputs only if not passed as parameters */
587 if (open_inputs_ptr) *open_inputs_ptr = open_inputs;
588 else avfilter_inout_free(&open_inputs);
589 if (open_outputs_ptr) *open_outputs_ptr = open_outputs;
590 else avfilter_inout_free(&open_outputs);
591 avfilter_inout_free(&curr_inputs);
594 for (; graph->nb_filters > 0; graph->nb_filters--)
595 avfilter_free(graph->filters[graph->nb_filters - 1]);
596 av_freep(&graph->filters);