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
27 #include "avfiltergraph.h"
29 static AVFilterContext *create_filter(AVFilterGraph *ctx, int index,
30 const char *name, const char *args,
33 AVFilterContext *filt;
38 snprintf(inst_name, sizeof(inst_name), "Parsed filter %d", index);
40 if(!(filterdef = avfilter_get_by_name(name))) {
41 av_log(log_ctx, AV_LOG_ERROR,
42 "no such filter: '%s'\n", name);
46 if(!(filt = avfilter_open(filterdef, inst_name))) {
47 av_log(log_ctx, AV_LOG_ERROR,
48 "error creating filter '%s'\n", name);
52 if(avfilter_graph_add_filter(ctx, filt) < 0)
55 if(avfilter_init_filter(filt, args, NULL)) {
56 av_log(log_ctx, AV_LOG_ERROR,
57 "error initializing filter '%s' with args '%s'\n", name, args);
64 static int link_filter(AVFilterContext *src, int srcpad,
65 AVFilterContext *dst, int dstpad,
68 if(avfilter_link(src, srcpad, dst, dstpad)) {
69 av_log(log_ctx, AV_LOG_ERROR,
70 "cannot create the link %s:%d -> %s:%d\n",
71 src->filter->name, srcpad, dst->filter->name, dstpad);
78 static void consume_whitespace(const char **buf)
80 *buf += strspn(*buf, " \n\t");
84 * Consumes a string from *buf.
85 * @return a copy of the consumed string, which should be free'd after use
87 static char *consume_string(const char **buf)
89 char *out = av_malloc(strlen(*buf) + 1);
92 consume_whitespace(buf);
101 while(**buf && **buf != '\'')
121 consume_whitespace(buf);
128 * @arg name a pointer (that need to be free'd after use) to the name between
131 static void parse_link_name(const char **buf, char **name, AVClass *log_ctx)
133 const char *start = *buf;
136 *name = consume_string(buf);
139 av_log(log_ctx, AV_LOG_ERROR,
140 "Bad (empty?) label found in the following: \"%s\".\n", start);
144 if(*(*buf)++ != ']') {
145 av_log(log_ctx, AV_LOG_ERROR,
146 "Mismatched '[' found in the following: \"%s\".\n", start);
159 * A linked-list of the inputs/outputs of the filter chain.
161 typedef struct AVFilterInOut {
164 AVFilterContext *filter;
167 struct AVFilterInOut *next;
170 static void free_inout(AVFilterInOut *head)
173 AVFilterInOut *next = head->next;
179 static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
183 while(*links && strcmp((*links)->name, label))
184 links = &((*links)->next);
195 static int link_filter_inouts(AVFilterContext *filter,
196 AVFilterInOut **currInputs,
197 AVFilterInOut **openLinks, AVClass *log_ctx)
201 pad = filter->input_count;
203 AVFilterInOut *p= *currInputs;
204 *currInputs = (*currInputs)->next;
206 av_log(log_ctx, AV_LOG_ERROR,
207 "Not enough inputs specified for the \"%s\" filter.\n",
213 if(link_filter(p->filter, p->pad_idx, filter, pad, log_ctx))
219 p->next = *openLinks;
226 av_log(log_ctx, AV_LOG_ERROR,
227 "Too many inputs specified for the \"%s\" filter.\n",
232 pad = filter->output_count;
234 AVFilterInOut *currlinkn = av_malloc(sizeof(AVFilterInOut));
235 currlinkn->name = NULL;
236 currlinkn->type = LinkTypeOut;
237 currlinkn->filter = filter;
238 currlinkn->pad_idx = pad;
239 currlinkn->next = *currInputs;
240 *currInputs = currlinkn;
247 * Parse "filter=params"
248 * @arg name a pointer (that need to be free'd after use) to the name of the
250 * @arg ars a pointer (that need to be free'd after use) to the args of the
253 static AVFilterContext *parse_filter(const char **buf, AVFilterGraph *graph,
254 int index, AVClass *log_ctx)
257 char *name = consume_string(buf);
261 opts = consume_string(buf);
266 return create_filter(graph, index, name, opts, log_ctx);
269 static int parse_inputs(const char **buf, AVFilterInOut **currInputs,
270 AVFilterInOut **openLinks, AVClass *log_ctx)
274 while(**buf == '[') {
276 AVFilterInOut *link_to_add;
277 AVFilterInOut *match;
279 parse_link_name(buf, &name, log_ctx);
284 /* First check if the label is not in the openLinks list */
285 match = extract_inout(name, openLinks);
288 /* A label of a open link. Make it one of the inputs of the next
290 if(match->type != LinkTypeOut) {
291 av_log(log_ctx, AV_LOG_ERROR,
292 "Label \"%s\" appears twice as input!\n", match->name);
298 /* Not in the list, so add it as an input */
299 link_to_add = av_malloc(sizeof(AVFilterInOut));
301 link_to_add->name = name;
302 link_to_add->type = LinkTypeIn;
303 link_to_add->filter = NULL;
304 link_to_add->pad_idx = pad;
306 link_to_add->next = *currInputs;
307 *currInputs = link_to_add;
308 consume_whitespace(buf);
315 static int parse_outputs(const char **buf, AVFilterInOut **currInputs,
316 AVFilterInOut **openLinks, AVClass *log_ctx)
320 while(**buf == '[') {
322 AVFilterInOut *match;
324 AVFilterInOut *input = *currInputs;
325 *currInputs = (*currInputs)->next;
327 parse_link_name(buf, &name, log_ctx);
332 /* First check if the label is not in the openLinks list */
333 match = extract_inout(name, openLinks);
336 /* A label of a open link. Link it. */
337 if(match->type != LinkTypeIn) {
338 av_log(log_ctx, AV_LOG_ERROR,
339 "Label \"%s\" appears twice as output!\n", match->name);
343 if(link_filter(input->filter, input->pad_idx,
344 match->filter, match->pad_idx, log_ctx) < 0)
349 /* Not in the list, so add the first input as a openLink */
350 input->next = *openLinks;
351 input->type = LinkTypeOut;
355 consume_whitespace(buf);
363 * Parse a string describing a filter graph.
365 int avfilter_parse_graph(AVFilterGraph *graph, const char *filters,
366 AVFilterContext *in, int inpad,
367 AVFilterContext *out, int outpad,
374 AVFilterInOut *currInputs=NULL;
375 AVFilterInOut *openLinks = av_malloc(sizeof(AVFilterInOut));
377 openLinks->name = "in";
378 openLinks->filter = in;
379 openLinks->type = LinkTypeOut;
380 openLinks->pad_idx = inpad;
381 openLinks->next = av_malloc(sizeof(AVFilterInOut));
383 openLinks->next->name = "out";
384 openLinks->next->filter = out;
385 openLinks->next->type = LinkTypeIn;
386 openLinks->next->pad_idx = outpad;
387 openLinks->next->next = NULL;
390 AVFilterContext *filter;
391 consume_whitespace(&filters);
393 pad = parse_inputs(&filters, &currInputs, &openLinks, log_ctx);
398 if(!(filter = parse_filter(&filters, graph, index, log_ctx)))
401 if(filter->input_count == 1 && !currInputs && !index) {
402 // First input can be ommitted if it is "[in]"
403 const char *tmp = "[in]";
404 pad = parse_inputs(&tmp, &currInputs, &openLinks, log_ctx);
409 if(link_filter_inouts(filter, &currInputs, &openLinks, log_ctx) < 0)
412 pad = parse_outputs(&filters, &currInputs, &openLinks, log_ctx);
417 consume_whitespace(&filters);
420 if(chr == ';' && currInputs) {
421 av_log(log_ctx, AV_LOG_ERROR,
422 "Could not find a output to link when parsing \"%s\"\n",
427 } while(chr == ',' || chr == ';');
429 if(openLinks && !strcmp(openLinks->name, "out") && currInputs) {
430 // Last output can be ommitted if it is "[out]"
431 const char *tmp = "[out]";
432 if(parse_outputs(&tmp, &currInputs, &openLinks, log_ctx) < 0)
439 avfilter_destroy_graph(graph);
440 free_inout(openLinks);
441 free_inout(currInputs);