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, "]");
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 filter %d %s", index, filt_name);
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'", filt_name);
131 av_log(log_ctx, AV_LOG_ERROR, " with args '%s'", args);
132 av_log(log_ctx, AV_LOG_ERROR, "\n");
133 avfilter_free(*filt_ctx);
141 * Parse a string of the form FILTER_NAME[=PARAMS], and create a
142 * corresponding filter instance which is added to graph with
145 * @param filt_ctx Pointer that is set to the created and configured filter
146 * context on success, set to NULL on failure.
147 * @param filt_ctx put here a pointer to the created filter context on
148 * success, NULL otherwise
149 * @param buf pointer to the buffer to parse, *buf will be updated to
150 * point to the char next after the parsed string
151 * @param index an index which is assigned to the created filter
152 * instance, and which is supposed to be unique for each filter
153 * instance added to the filtergraph
154 * @return 0 in case of success, a negative AVERROR code otherwise
156 static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
157 int index, void *log_ctx)
160 char *name = av_get_token(buf, "=,;[\n");
165 opts = av_get_token(buf, "[],;\n");
168 ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
174 AVFilterInOut *avfilter_inout_alloc(void)
176 return av_mallocz(sizeof(AVFilterInOut));
179 void avfilter_inout_free(AVFilterInOut **inout)
182 AVFilterInOut *next = (*inout)->next;
183 av_freep(&(*inout)->name);
189 static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
193 while (*links && (!(*links)->name || strcmp((*links)->name, label)))
194 links = &((*links)->next);
206 static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
208 element->next = *inouts;
212 static void append_inout(AVFilterInOut **inouts, AVFilterInOut **element)
214 while (*inouts && (*inouts)->next)
215 inouts = &((*inouts)->next);
220 (*inouts)->next = *element;
224 static int link_filter_inouts(AVFilterContext *filt_ctx,
225 AVFilterInOut **curr_inputs,
226 AVFilterInOut **open_inputs, void *log_ctx)
230 for (pad = 0; pad < filt_ctx->nb_inputs; pad++) {
231 AVFilterInOut *p = *curr_inputs;
234 *curr_inputs = (*curr_inputs)->next;
236 } else if (!(p = av_mallocz(sizeof(*p))))
237 return AVERROR(ENOMEM);
240 ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx);
246 p->filter_ctx = filt_ctx;
248 append_inout(open_inputs, &p);
253 av_log(log_ctx, AV_LOG_ERROR,
254 "Too many inputs specified for the \"%s\" filter.\n",
255 filt_ctx->filter->name);
256 return AVERROR(EINVAL);
259 pad = filt_ctx->nb_outputs;
261 AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
263 return AVERROR(ENOMEM);
264 currlinkn->filter_ctx = filt_ctx;
265 currlinkn->pad_idx = pad;
266 insert_inout(curr_inputs, currlinkn);
272 static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
273 AVFilterInOut **open_outputs, void *log_ctx)
275 AVFilterInOut *parsed_inputs = NULL;
278 while (**buf == '[') {
279 char *name = parse_link_name(buf, log_ctx);
280 AVFilterInOut *match;
283 return AVERROR(EINVAL);
285 /* First check if the label is not in the open_outputs list */
286 match = extract_inout(name, open_outputs);
291 /* Not in the list, so add it as an input */
292 if (!(match = av_mallocz(sizeof(AVFilterInOut)))) {
294 return AVERROR(ENOMEM);
297 match->pad_idx = pad;
300 append_inout(&parsed_inputs, &match);
302 *buf += strspn(*buf, WHITESPACES);
306 append_inout(&parsed_inputs, curr_inputs);
307 *curr_inputs = parsed_inputs;
312 static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
313 AVFilterInOut **open_inputs,
314 AVFilterInOut **open_outputs, void *log_ctx)
318 while (**buf == '[') {
319 char *name = parse_link_name(buf, log_ctx);
320 AVFilterInOut *match;
322 AVFilterInOut *input = *curr_inputs;
325 return AVERROR(EINVAL);
328 av_log(log_ctx, AV_LOG_ERROR,
329 "No output pad can be associated to link label '%s'.\n", name);
331 return AVERROR(EINVAL);
333 *curr_inputs = (*curr_inputs)->next;
335 /* First check if the label is not in the open_inputs list */
336 match = extract_inout(name, open_inputs);
339 if ((ret = link_filter(input->filter_ctx, input->pad_idx,
340 match->filter_ctx, match->pad_idx, log_ctx)) < 0) {
344 av_free(match->name);
349 /* Not in the list, so add the first input as a open_output */
351 insert_inout(open_outputs, input);
353 *buf += strspn(*buf, WHITESPACES);
360 static int parse_sws_flags(const char **buf, AVFilterGraph *graph)
362 char *p = strchr(*buf, ';');
364 if (strncmp(*buf, "sws_flags=", 10))
368 av_log(graph, AV_LOG_ERROR, "sws_flags not terminated with ';'.\n");
369 return AVERROR(EINVAL);
372 *buf += 4; // keep the 'flags=' part
374 av_freep(&graph->scale_sws_opts);
375 if (!(graph->scale_sws_opts = av_mallocz(p - *buf + 1)))
376 return AVERROR(ENOMEM);
377 av_strlcpy(graph->scale_sws_opts, *buf, p - *buf + 1);
383 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
384 AVFilterInOut **inputs,
385 AVFilterInOut **outputs)
390 AVFilterInOut *curr_inputs = NULL, *open_inputs = NULL, *open_outputs = NULL;
392 filters += strspn(filters, WHITESPACES);
394 if ((ret = parse_sws_flags(&filters, graph)) < 0)
398 AVFilterContext *filter;
399 filters += strspn(filters, WHITESPACES);
401 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);
433 *inputs = open_inputs;
434 *outputs = open_outputs;
438 while (graph->nb_filters)
439 avfilter_free(graph->filters[0]);
440 av_freep(&graph->filters);
441 avfilter_inout_free(&open_inputs);
442 avfilter_inout_free(&open_outputs);
443 avfilter_inout_free(&curr_inputs);
451 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
452 AVFilterInOut *open_inputs,
453 AVFilterInOut *open_outputs, void *log_ctx)
456 AVFilterInOut *cur, *match, *inputs = NULL, *outputs = NULL;
458 if ((ret = avfilter_graph_parse2(graph, filters, &inputs, &outputs)) < 0)
461 /* First input can be omitted if it is "[in]" */
462 if (inputs && !inputs->name)
463 inputs->name = av_strdup("in");
464 for (cur = inputs; cur; cur = cur->next) {
466 av_log(log_ctx, AV_LOG_ERROR,
467 "Not enough inputs specified for the \"%s\" filter.\n",
468 cur->filter_ctx->filter->name);
469 ret = AVERROR(EINVAL);
472 if (!(match = extract_inout(cur->name, &open_outputs)))
474 ret = avfilter_link(match->filter_ctx, match->pad_idx,
475 cur->filter_ctx, cur->pad_idx);
476 avfilter_inout_free(&match);
481 /* Last output can be omitted if it is "[out]" */
482 if (outputs && !outputs->name)
483 outputs->name = av_strdup("out");
484 for (cur = outputs; cur; cur = cur->next) {
486 av_log(log_ctx, AV_LOG_ERROR,
487 "Invalid filterchain containing an unlabelled output pad: \"%s\"\n",
489 ret = AVERROR(EINVAL);
492 if (!(match = extract_inout(cur->name, &open_inputs)))
494 ret = avfilter_link(cur->filter_ctx, cur->pad_idx,
495 match->filter_ctx, match->pad_idx);
496 avfilter_inout_free(&match);
503 while (graph->nb_filters)
504 avfilter_free(graph->filters[0]);
505 av_freep(&graph->filters);
507 avfilter_inout_free(&inputs);
508 avfilter_inout_free(&outputs);
509 avfilter_inout_free(&open_inputs);
510 avfilter_inout_free(&open_outputs);