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"
30 #define WHITESPACES " \n\t"
33 * Link two filters together.
35 * @see avfilter_link()
37 static int link_filter(AVFilterContext *src, int srcpad,
38 AVFilterContext *dst, int dstpad,
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);
53 * Parse the name of a link, which has the format "[linkname]".
55 * @return a pointer (that need to be freed after use) to the name
58 static char *parse_link_name(const char **buf, void *log_ctx)
60 const char *start = *buf;
64 name = av_get_token(buf, "]");
67 av_log(log_ctx, AV_LOG_ERROR,
68 "Bad (empty?) label found in the following: \"%s\".\n", start);
72 if (*(*buf)++ != ']') {
73 av_log(log_ctx, AV_LOG_ERROR,
74 "Mismatched '[' found in the following: \"%s\".\n", start);
83 * Create an instance of a filter, initialize and insert it in the
84 * filtergraph in *ctx.
86 * @param filt_ctx put here a filter context in case of successful creation and configuration, NULL otherwise.
87 * @param ctx the filtergraph context
88 * @param index an index which is supposed to be unique for each filter instance added to the filtergraph
89 * @param filt_name the name of the filter to create
90 * @param args the arguments provided to the filter during its initialization
91 * @param log_ctx the log context to use
92 * @return 0 in case of success, a negative AVERROR code otherwise
94 static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index,
95 const char *filt_name, const char *args, void *log_ctx)
102 snprintf(inst_name, sizeof(inst_name), "Parsed_%s_%d", filt_name, index);
104 filt = avfilter_get_by_name(filt_name);
107 av_log(log_ctx, AV_LOG_ERROR,
108 "No such filter: '%s'\n", filt_name);
109 return AVERROR(EINVAL);
112 *filt_ctx = avfilter_graph_alloc_filter(ctx, filt, inst_name);
114 av_log(log_ctx, AV_LOG_ERROR,
115 "Error creating filter '%s'\n", filt_name);
116 return AVERROR(ENOMEM);
119 if (!strcmp(filt_name, "scale") && args && !strstr(args, "flags") &&
120 ctx->scale_sws_opts) {
121 snprintf(tmp_args, sizeof(tmp_args), "%s:%s",
122 args, ctx->scale_sws_opts);
126 ret = avfilter_init_str(*filt_ctx, args);
128 av_log(log_ctx, AV_LOG_ERROR,
129 "Error initializing filter '%s' with args '%s'\n", filt_name, args);
137 * Parse a string of the form FILTER_NAME[=PARAMS], and create a
138 * corresponding filter instance which is added to graph with
141 * @param filt_ctx Pointer that is set to the created and configured filter
142 * context on success, set to NULL on failure.
143 * @param filt_ctx put here a pointer to the created filter context on
144 * success, NULL otherwise
145 * @param buf pointer to the buffer to parse, *buf will be updated to
146 * point to the char next after the parsed string
147 * @param index an index which is assigned to the created filter
148 * instance, and which is supposed to be unique for each filter
149 * instance added to the filtergraph
150 * @return 0 in case of success, a negative AVERROR code otherwise
152 static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
153 int index, void *log_ctx)
156 char *name = av_get_token(buf, "=,;[\n");
161 opts = av_get_token(buf, "[],;\n");
164 ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
170 AVFilterInOut *avfilter_inout_alloc(void)
172 return av_mallocz(sizeof(AVFilterInOut));
175 void avfilter_inout_free(AVFilterInOut **inout)
178 AVFilterInOut *next = (*inout)->next;
179 av_freep(&(*inout)->name);
185 static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
189 while (*links && (!(*links)->name || strcmp((*links)->name, label)))
190 links = &((*links)->next);
202 static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
204 element->next = *inouts;
208 static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
210 while (*inouts && (*inouts)->next)
211 inouts = &((*inouts)->next);
216 (*inouts)->next = *element;
220 static int link_filter_inouts(AVFilterContext *filt_ctx,
221 AVFilterInOut **curr_inputs,
222 AVFilterInOut **open_inputs, void *log_ctx)
226 for (pad = 0; pad < filt_ctx->nb_inputs; pad++) {
227 AVFilterInOut *p = *curr_inputs;
230 *curr_inputs = (*curr_inputs)->next;
232 } else if (!(p = av_mallocz(sizeof(*p))))
233 return AVERROR(ENOMEM);
236 ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx);
242 p->filter_ctx = filt_ctx;
244 append_inout(open_inputs, &p);
249 av_log(log_ctx, AV_LOG_ERROR,
250 "Too many inputs specified for the \"%s\" filter.\n",
251 filt_ctx->filter->name);
252 return AVERROR(EINVAL);
255 pad = filt_ctx->nb_outputs;
257 AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
259 return AVERROR(ENOMEM);
260 currlinkn->filter_ctx = filt_ctx;
261 currlinkn->pad_idx = pad;
262 insert_inout(curr_inputs, currlinkn);
268 static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
269 AVFilterInOut **open_outputs, void *log_ctx)
271 AVFilterInOut *parsed_inputs = NULL;
274 while (**buf == '[') {
275 char *name = parse_link_name(buf, log_ctx);
276 AVFilterInOut *match;
279 return AVERROR(EINVAL);
281 /* First check if the label is not in the open_outputs list */
282 match = extract_inout(name, open_outputs);
287 /* Not in the list, so add it as an input */
288 if (!(match = av_mallocz(sizeof(AVFilterInOut)))) {
290 return AVERROR(ENOMEM);
293 match->pad_idx = pad;
296 append_inout(&parsed_inputs, &match);
298 *buf += strspn(*buf, WHITESPACES);
302 append_inout(&parsed_inputs, curr_inputs);
303 *curr_inputs = parsed_inputs;
308 static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
309 AVFilterInOut **open_inputs,
310 AVFilterInOut **open_outputs, void *log_ctx)
314 while (**buf == '[') {
315 char *name = parse_link_name(buf, log_ctx);
316 AVFilterInOut *match;
318 AVFilterInOut *input = *curr_inputs;
321 return AVERROR(EINVAL);
324 av_log(log_ctx, AV_LOG_ERROR,
325 "No output pad can be associated to link label '%s'.\n", name);
327 return AVERROR(EINVAL);
329 *curr_inputs = (*curr_inputs)->next;
331 /* First check if the label is not in the open_inputs list */
332 match = extract_inout(name, open_inputs);
335 if ((ret = link_filter(input->filter_ctx, input->pad_idx,
336 match->filter_ctx, match->pad_idx, log_ctx)) < 0) {
340 av_free(match->name);
345 /* Not in the list, so add the first input as a open_output */
347 insert_inout(open_outputs, input);
349 *buf += strspn(*buf, WHITESPACES);
356 static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
358 char *p = strchr(*buf, ';');
360 if (strncmp(*buf, "sws_flags=", 10))
364 av_log(graph, AV_LOG_ERROR, "sws_flags not terminated with ';'.\n");
365 return AVERROR(EINVAL);
368 *buf += 4; // keep the 'flags=' part
370 av_freep(&graph->scale_sws_opts);
371 if (!(graph->scale_sws_opts = av_mallocz(p - *buf + 1)))
372 return AVERROR(ENOMEM);
373 av_strlcpy(graph->scale_sws_opts, *buf, p - *buf + 1);
379 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
380 AVFilterInOut **inputs,
381 AVFilterInOut **outputs)
383 int index = 0, ret = 0;
386 AVFilterInOut *curr_inputs = NULL, *open_inputs = NULL, *open_outputs = NULL;
388 filters += strspn(filters, WHITESPACES);
390 if ((ret = parse_sws_flags(&filters, graph)) < 0)
394 AVFilterContext *filter;
395 filters += strspn(filters, WHITESPACES);
397 if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, graph)) < 0)
399 if ((ret = parse_filter(&filter, &filters, graph, index, graph)) < 0)
403 if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, graph)) < 0)
406 if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
410 filters += strspn(filters, WHITESPACES);
413 if (chr == ';' && curr_inputs)
414 append_inout(&open_outputs, &curr_inputs);
416 } while (chr == ',' || chr == ';');
419 av_log(graph, AV_LOG_ERROR,
420 "Unable to parse graph description substring: \"%s\"\n",
422 ret = AVERROR(EINVAL);
426 append_inout(&open_outputs, &curr_inputs);
429 *inputs = open_inputs;
430 *outputs = open_outputs;
434 while (graph->nb_filters)
435 avfilter_free(graph->filters[0]);
436 av_freep(&graph->filters);
437 avfilter_inout_free(&open_inputs);
438 avfilter_inout_free(&open_outputs);
439 avfilter_inout_free(&curr_inputs);
447 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
448 AVFilterInOut **open_inputs_ptr, AVFilterInOut **open_outputs_ptr,
453 AVFilterInOut *open_inputs = open_inputs_ptr ? *open_inputs_ptr : NULL;
454 AVFilterInOut *open_outputs = open_outputs_ptr ? *open_outputs_ptr : NULL;
455 AVFilterInOut *cur, *match, *inputs = NULL, *outputs = NULL;
457 if ((ret = avfilter_graph_parse2(graph, filters, &inputs, &outputs)) < 0)
460 /* First input can be omitted if it is "[in]" */
461 if (inputs && !inputs->name)
462 inputs->name = av_strdup("in");
463 for (cur = inputs; cur; cur = cur->next) {
465 av_log(log_ctx, AV_LOG_ERROR,
466 "Not enough inputs specified for the \"%s\" filter.\n",
467 cur->filter_ctx->filter->name);
468 ret = AVERROR(EINVAL);
471 if (!(match = extract_inout(cur->name, &open_outputs)))
473 ret = avfilter_link(match->filter_ctx, match->pad_idx,
474 cur->filter_ctx, cur->pad_idx);
475 avfilter_inout_free(&match);
480 /* Last output can be omitted if it is "[out]" */
481 if (outputs && !outputs->name)
482 outputs->name = av_strdup("out");
483 for (cur = outputs; cur; cur = cur->next) {
485 av_log(log_ctx, AV_LOG_ERROR,
486 "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
488 ret = AVERROR(EINVAL);
491 if (!(match = extract_inout(cur->name, &open_inputs)))
493 ret = avfilter_link(cur->filter_ctx, cur->pad_idx,
494 match->filter_ctx, match->pad_idx);
495 avfilter_inout_free(&match);
502 while (graph->nb_filters)
503 avfilter_free(graph->filters[0]);
504 av_freep(&graph->filters);
506 avfilter_inout_free(&inputs);
507 avfilter_inout_free(&outputs);
508 /* clear open_in/outputs only if not passed as parameters */
509 if (open_inputs_ptr) *open_inputs_ptr = open_inputs;
510 else avfilter_inout_free(&open_inputs);
511 if (open_outputs_ptr) *open_outputs_ptr = open_outputs;
512 else avfilter_inout_free(&open_outputs);
516 int index = 0, ret = 0;
519 AVFilterInOut *curr_inputs = NULL;
520 AVFilterInOut *open_inputs = open_inputs_ptr ? *open_inputs_ptr : NULL;
521 AVFilterInOut *open_outputs = open_outputs_ptr ? *open_outputs_ptr : NULL;
523 if ((ret = parse_sws_flags(&filters, graph)) < 0)
527 AVFilterContext *filter;
528 const char *filterchain = filters;
529 filters += strspn(filters, WHITESPACES);
531 if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx)) < 0)
534 if ((ret = parse_filter(&filter, &filters, graph, index, log_ctx)) < 0)
537 if (filter->input_count == 1 && !curr_inputs && !index) {
538 /* First input pad, assume it is "[in]" if not specified */
539 const char *tmp = "[in]";
540 if ((ret = parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx)) < 0)
544 if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx)) < 0)
547 if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
551 filters += strspn(filters, WHITESPACES);
554 if (chr == ';' && curr_inputs) {
555 av_log(log_ctx, AV_LOG_ERROR,
556 "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
558 ret = AVERROR(EINVAL);
562 } while (chr == ',' || chr == ';');
565 av_log(log_ctx, AV_LOG_ERROR,
566 "Unable to parse graph description substring: \"%s\"\n",
568 ret = AVERROR(EINVAL);
573 /* Last output pad, assume it is "[out]" if not specified */
574 const char *tmp = "[out]";
575 if ((ret = parse_outputs(&tmp, &curr_inputs, &open_inputs, &open_outputs,
581 /* clear open_in/outputs only if not passed as parameters */
582 if (open_inputs_ptr) *open_inputs_ptr = open_inputs;
583 else avfilter_inout_free(&open_inputs);
584 if (open_outputs_ptr) *open_outputs_ptr = open_outputs;
585 else avfilter_inout_free(&open_outputs);
586 avfilter_inout_free(&curr_inputs);
589 while (graph->nb_filters)
590 avfilter_free(graph->filters[0]);
591 av_freep(&graph->filters);