3 * Copyright (c) 2008 Vitor Sessak
4 * Copyright (c) 2007 Bobby Bingham
6 * This file is part of Libav.
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.
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.
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
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, "]");
69 av_log(log_ctx, AV_LOG_ERROR,
70 "Bad (empty?) label found in the following: \"%s\".\n", start);
74 if (*(*buf)++ != ']') {
75 av_log(log_ctx, AV_LOG_ERROR,
76 "Mismatched '[' found in the following: \"%s\".\n", start);
84 #define TMP_ARGS_SIZE 256
86 static void append_sws_flags(const char **args, const char *sws_opts, char *tmp)
89 const char *separator = ":";
90 const char *opt = *args;
92 if (strstr(*args, "flags"))
95 if (strstr(*args, "="))
96 separator = ":flags=";
98 while ((opt = strstr(opt, ":")) && *opt) {
99 av_log(NULL, AV_LOG_INFO, "opts '%s' \n", opt);
107 opt = strstr(sws_opts, "flags=");
108 if (opt && strlen(opt) > 6)
113 snprintf(tmp, TMP_ARGS_SIZE, "%s%s%s",
114 *args, separator, opt);
120 * Create an instance of a filter, initialize and insert it in the
121 * filtergraph in *ctx.
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
131 static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index,
132 const char *filt_name, const char *args, void *log_ctx)
136 char tmp_args[TMP_ARGS_SIZE];
139 snprintf(inst_name, sizeof(inst_name), "Parsed filter %d %s", index, filt_name);
141 filt = avfilter_get_by_name(filt_name);
144 av_log(log_ctx, AV_LOG_ERROR,
145 "No such filter: '%s'\n", filt_name);
146 return AVERROR(EINVAL);
149 *filt_ctx = avfilter_graph_alloc_filter(ctx, filt, inst_name);
151 av_log(log_ctx, AV_LOG_ERROR,
152 "Error creating filter '%s'\n", filt_name);
153 return AVERROR(ENOMEM);
156 if (!strcmp(filt_name, "scale") && args &&
157 ctx->scale_sws_opts) {
158 append_sws_flags(&args, ctx->scale_sws_opts, tmp_args);
161 ret = avfilter_init_str(*filt_ctx, args);
163 av_log(log_ctx, AV_LOG_ERROR,
164 "Error initializing filter '%s'", filt_name);
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);
176 * Parse a string of the form FILTER_NAME[=PARAMS], and create a
177 * corresponding filter instance which is added to graph with
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
191 static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
192 int index, void *log_ctx)
195 char *name = av_get_token(buf, "=,;[\n");
200 opts = av_get_token(buf, "[],;\n");
203 ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
209 AVFilterInOut *avfilter_inout_alloc(void)
211 return av_mallocz(sizeof(AVFilterInOut));
214 void avfilter_inout_free(AVFilterInOut **inout)
217 AVFilterInOut *next = (*inout)->next;
218 av_freep(&(*inout)->name);
224 static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
228 while (*links && (!(*links)->name || strcmp((*links)->name, label)))
229 links = &((*links)->next);
241 static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
243 element->next = *inouts;
247 static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
249 while (*inouts && (*inouts)->next)
250 inouts = &((*inouts)->next);
255 (*inouts)->next = *element;
259 static int link_filter_inouts(AVFilterContext *filt_ctx,
260 AVFilterInOut **curr_inputs,
261 AVFilterInOut **open_inputs, void *log_ctx)
265 for (pad = 0; pad < filt_ctx->nb_inputs; pad++) {
266 AVFilterInOut *p = *curr_inputs;
269 *curr_inputs = (*curr_inputs)->next;
271 } else if (!(p = av_mallocz(sizeof(*p))))
272 return AVERROR(ENOMEM);
275 ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx);
281 p->filter_ctx = filt_ctx;
283 append_inout(open_inputs, &p);
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);
294 pad = filt_ctx->nb_outputs;
296 AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
298 return AVERROR(ENOMEM);
299 currlinkn->filter_ctx = filt_ctx;
300 currlinkn->pad_idx = pad;
301 insert_inout(curr_inputs, currlinkn);
307 static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
308 AVFilterInOut **open_outputs, void *log_ctx)
310 AVFilterInOut *parsed_inputs = NULL;
313 while (**buf == '[') {
314 char *name = parse_link_name(buf, log_ctx);
315 AVFilterInOut *match;
318 return AVERROR(EINVAL);
320 /* First check if the label is not in the open_outputs list */
321 match = extract_inout(name, open_outputs);
326 /* Not in the list, so add it as an input */
327 if (!(match = av_mallocz(sizeof(AVFilterInOut)))) {
329 return AVERROR(ENOMEM);
332 match->pad_idx = pad;
335 append_inout(&parsed_inputs, &match);
337 *buf += strspn(*buf, WHITESPACES);
341 append_inout(&parsed_inputs, curr_inputs);
342 *curr_inputs = parsed_inputs;
347 static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
348 AVFilterInOut **open_inputs,
349 AVFilterInOut **open_outputs, void *log_ctx)
353 while (**buf == '[') {
354 char *name = parse_link_name(buf, log_ctx);
355 AVFilterInOut *match;
357 AVFilterInOut *input = *curr_inputs;
360 return AVERROR(EINVAL);
363 av_log(log_ctx, AV_LOG_ERROR,
364 "No output pad can be associated to link label '%s'.\n", name);
366 return AVERROR(EINVAL);
368 *curr_inputs = (*curr_inputs)->next;
370 /* First check if the label is not in the open_inputs list */
371 match = extract_inout(name, open_inputs);
374 if ((ret = link_filter(input->filter_ctx, input->pad_idx,
375 match->filter_ctx, match->pad_idx, log_ctx)) < 0) {
379 av_free(match->name);
384 /* Not in the list, so add the first input as a open_output */
386 insert_inout(open_outputs, input);
388 *buf += strspn(*buf, WHITESPACES);
395 static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
397 char *p = strchr(*buf, ';');
399 if (strncmp(*buf, "sws_flags=", 10))
403 av_log(graph, AV_LOG_ERROR, "sws_flags not terminated with ';'.\n");
404 return AVERROR(EINVAL);
407 *buf += 4; // keep the 'flags=' part
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);
418 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
419 AVFilterInOut **inputs,
420 AVFilterInOut **outputs)
425 AVFilterInOut *curr_inputs = NULL, *open_inputs = NULL, *open_outputs = NULL;
427 filters += strspn(filters, WHITESPACES);
429 if ((ret = parse_sws_flags(&filters, graph)) < 0)
433 AVFilterContext *filter;
434 filters += strspn(filters, WHITESPACES);
436 if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, graph)) < 0)
439 if ((ret = parse_filter(&filter, &filters, graph, index, graph)) < 0)
443 if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, graph)) < 0)
446 if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
450 filters += strspn(filters, WHITESPACES);
453 if (chr == ';' && curr_inputs)
454 append_inout(&open_outputs, &curr_inputs);
456 } while (chr == ',' || chr == ';');
459 av_log(graph, AV_LOG_ERROR,
460 "Unable to parse graph description substring: \"%s\"\n",
462 ret = AVERROR(EINVAL);
466 append_inout(&open_outputs, &curr_inputs);
468 *inputs = open_inputs;
469 *outputs = open_outputs;
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);
486 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
487 AVFilterInOut *open_inputs,
488 AVFilterInOut *open_outputs, void *log_ctx)
491 AVFilterInOut *cur, *match, *inputs = NULL, *outputs = NULL;
493 if ((ret = avfilter_graph_parse2(graph, filters, &inputs, &outputs)) < 0)
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) {
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);
507 if (!(match = extract_inout(cur->name, &open_outputs)))
509 ret = avfilter_link(match->filter_ctx, match->pad_idx,
510 cur->filter_ctx, cur->pad_idx);
511 avfilter_inout_free(&match);
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) {
521 av_log(log_ctx, AV_LOG_ERROR,
522 "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
524 ret = AVERROR(EINVAL);
527 if (!(match = extract_inout(cur->name, &open_inputs)))
529 ret = avfilter_link(cur->filter_ctx, cur->pad_idx,
530 match->filter_ctx, match->pad_idx);
531 avfilter_inout_free(&match);
538 while (graph->nb_filters)
539 avfilter_free(graph->filters[0]);
540 av_freep(&graph->filters);
542 avfilter_inout_free(&inputs);
543 avfilter_inout_free(&outputs);
544 avfilter_inout_free(&open_inputs);
545 avfilter_inout_free(&open_outputs);