Make parse_outputs() always return meaningful error codes.
[libav.git] / libavfilter / graphparser.c
CommitLineData
27afb09d
VS
1/*
2 * filter graph parser
3 * copyright (c) 2008 Vitor Sessak
4 * copyright (c) 2007 Bobby Bingham
5 *
6 * This file is part of FFmpeg.
7 *
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.
12 *
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.
17 *
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
21 */
22
23#include <ctype.h>
24#include <string.h>
25
372e2884 26#include "libavutil/avstring.h"
6a0c770b 27#include "graphparser.h"
27afb09d
VS
28#include "avfilter.h"
29#include "avfiltergraph.h"
dd04911c 30#include "parseutils.h"
27afb09d 31
fd548e5b
SS
32#define WHITESPACES " \n\t"
33
d2874a9d
SS
34/**
35 * Link two filters together.
36 *
37 * @see avfilter_link()
38 */
9710beaf 39static int link_filter(AVFilterContext *src, int srcpad,
3a70bb2d
VS
40 AVFilterContext *dst, int dstpad,
41 AVClass *log_ctx)
27afb09d 42{
99ac59ca
SS
43 int ret;
44 if ((ret = avfilter_link(src, srcpad, dst, dstpad))) {
3a70bb2d 45 av_log(log_ctx, AV_LOG_ERROR,
bb90d855 46 "Cannot create the link %s:%d -> %s:%d\n",
9710beaf 47 src->filter->name, srcpad, dst->filter->name, dstpad);
99ac59ca 48 return ret;
27afb09d
VS
49 }
50
51 return 0;
52}
53
27afb09d 54/**
94b2120d
SS
55 * Parse the name of a link, which has the format "[linkname]".
56 *
57 * @return a pointer (that need to be freed after use) to the name
58 * between parenthesis
27afb09d 59 */
bd80b349 60static char *parse_link_name(const char **buf, AVClass *log_ctx)
27afb09d 61{
22260824 62 const char *start = *buf;
bd80b349 63 char *name;
27afb09d
VS
64 (*buf)++;
65
dd04911c 66 name = av_get_token(buf, "]");
27afb09d 67
f219eee5 68 if (!name[0]) {
3a70bb2d 69 av_log(log_ctx, AV_LOG_ERROR,
22260824 70 "Bad (empty?) label found in the following: \"%s\".\n", start);
27afb09d 71 goto fail;
22260824 72 }
27afb09d 73
f219eee5 74 if (*(*buf)++ != ']') {
3a70bb2d 75 av_log(log_ctx, AV_LOG_ERROR,
22260824 76 "Mismatched '[' found in the following: \"%s\".\n", start);
85cb8af7 77 fail:
bd80b349 78 av_freep(&name);
22260824 79 }
bd80b349
VS
80
81 return name;
27afb09d
VS
82}
83
98137a1a
SS
84/**
85 * Create an instance of a filter, initialize and insert it in the
86 * filtergraph in *ctx.
87 *
88 * @param ctx the filtergraph context
c58572f8 89 * @param put here a filter context in case of successful creation and configuration, NULL otherwise.
98137a1a
SS
90 * @param index an index which is supposed to be unique for each filter instance added to the filtergraph
91 * @param filt_name the name of the filter to create
92 * @param args the arguments provided to the filter during its initialization
93 * @param log_ctx the log context to use
c58572f8 94 * @return 0 in case of success, a negative AVERROR code otherwise
98137a1a 95 */
c58572f8
SS
96static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index,
97 const char *filt_name, const char *args, AVClass *log_ctx)
8e74c889 98{
e4a5f397 99 AVFilter *filt;
8e74c889 100 char inst_name[30];
b5049814 101 char tmp_args[256];
c58572f8 102 int ret;
8e74c889 103
03c3bb5c 104 snprintf(inst_name, sizeof(inst_name), "Filter %d %s", index, filt_name);
8e74c889 105
e4a5f397 106 filt = avfilter_get_by_name(filt_name);
5e600185 107
f219eee5 108 if (!filt) {
8e74c889 109 av_log(log_ctx, AV_LOG_ERROR,
bb90d855 110 "No such filter: '%s'\n", filt_name);
c58572f8 111 return AVERROR(EINVAL);
8e74c889
VS
112 }
113
c58572f8
SS
114 ret = avfilter_open(filt_ctx, filt, inst_name);
115 if (!*filt_ctx) {
8e74c889 116 av_log(log_ctx, AV_LOG_ERROR,
bb90d855 117 "Error creating filter '%s'\n", filt_name);
c58572f8 118 return ret;
8e74c889
VS
119 }
120
c58572f8
SS
121 if ((ret = avfilter_graph_add_filter(ctx, *filt_ctx)) < 0) {
122 avfilter_destroy(*filt_ctx);
123 return ret;
64b164f4 124 }
8e74c889 125
b5049814
BC
126 if (!strcmp(filt_name, "scale") && !strstr(args, "flags")) {
127 snprintf(tmp_args, sizeof(tmp_args), "%s:%s",
128 args, ctx->scale_sws_opts);
129 args = tmp_args;
130 }
131
c58572f8 132 if ((ret = avfilter_init_filter(*filt_ctx, args, NULL)) < 0) {
8e74c889 133 av_log(log_ctx, AV_LOG_ERROR,
bb90d855 134 "Error initializing filter '%s' with args '%s'\n", filt_name, args);
c58572f8 135 return ret;
8e74c889
VS
136 }
137
c58572f8 138 return 0;
8e74c889
VS
139}
140
f5cbde2e
VS
141/**
142 * Parse "filter=params"
f5cbde2e 143 */
688b9dad
SS
144static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
145 int index, AVClass *log_ctx)
f5cbde2e 146{
ba3fed2f 147 char *opts = NULL;
15a316c0 148 char *name = av_get_token(buf, "=,;[\n");
c58572f8 149 int ret;
f5cbde2e 150
f219eee5 151 if (**buf == '=') {
f5cbde2e 152 (*buf)++;
15a316c0 153 opts = av_get_token(buf, "[],;\n");
12849837 154 }
f5cbde2e 155
688b9dad 156 ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
64b164f4
VS
157 av_free(name);
158 av_free(opts);
688b9dad 159 return ret;
f5cbde2e
VS
160}
161
27afb09d
VS
162static void free_inout(AVFilterInOut *head)
163{
f219eee5 164 while (head) {
55672c83 165 AVFilterInOut *next = head->next;
64b164f4 166 av_free(head->name);
27afb09d
VS
167 av_free(head);
168 head = next;
169 }
170}
171
c9987633
VS
172static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
173{
174 AVFilterInOut *ret;
c9987633 175
f219eee5 176 while (*links && strcmp((*links)->name, label))
f6557d5e 177 links = &((*links)->next);
c9987633 178
f6557d5e 179 ret = *links;
c9987633 180
f219eee5 181 if (ret)
f6557d5e 182 *links = ret->next;
c9987633
VS
183
184 return ret;
185}
186
e97908ee
VS
187static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
188{
189 element->next = *inouts;
190 *inouts = element;
191}
c9987633 192
ed581e65 193static int link_filter_inouts(AVFilterContext *filt_ctx,
7f9b3266
SS
194 AVFilterInOut **curr_inputs,
195 AVFilterInOut **open_inputs, AVClass *log_ctx)
c9987633 196{
ed581e65 197 int pad = filt_ctx->input_count, ret;
c9987633 198
f219eee5 199 while (pad--) {
7f9b3266 200 AVFilterInOut *p = *curr_inputs;
f219eee5 201 if (!p) {
c9987633
VS
202 av_log(log_ctx, AV_LOG_ERROR,
203 "Not enough inputs specified for the \"%s\" filter.\n",
ed581e65 204 filt_ctx->filter->name);
684ade49 205 return AVERROR(EINVAL);
c9987633
VS
206 }
207
7f9b3266 208 *curr_inputs = (*curr_inputs)->next;
4d11beb2 209
f219eee5 210 if (p->filter) {
ed581e65 211 if ((ret = link_filter(p->filter, p->pad_idx, filt_ctx, pad, log_ctx)) < 0)
684ade49 212 return ret;
64b164f4 213 av_free(p->name);
c9987633
VS
214 av_free(p);
215 } else {
ed581e65 216 p->filter = filt_ctx;
c9987633 217 p->pad_idx = pad;
7f9b3266 218 insert_inout(open_inputs, p);
c9987633
VS
219 }
220 }
221
f219eee5 222 if (*curr_inputs) {
c9987633
VS
223 av_log(log_ctx, AV_LOG_ERROR,
224 "Too many inputs specified for the \"%s\" filter.\n",
ed581e65 225 filt_ctx->filter->name);
684ade49 226 return AVERROR(EINVAL);
c9987633
VS
227 }
228
ed581e65 229 pad = filt_ctx->output_count;
f219eee5 230 while (pad--) {
c956dd43 231 AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
fbd97184
SS
232 if (!currlinkn)
233 return AVERROR(ENOMEM);
ed581e65 234 currlinkn->filter = filt_ctx;
c9987633 235 currlinkn->pad_idx = pad;
7f9b3266 236 insert_inout(curr_inputs, currlinkn);
c9987633
VS
237 }
238
239 return 0;
240}
241
7f9b3266
SS
242static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
243 AVFilterInOut **open_outputs, AVClass *log_ctx)
27afb09d 244{
c9987633 245 int pad = 0;
c9987633 246
f219eee5 247 while (**buf == '[') {
bd80b349 248 char *name = parse_link_name(buf, log_ctx);
b2ac16da 249 AVFilterInOut *match;
22260824 250
f219eee5 251 if (!name)
42e7f6d7 252 return AVERROR(EINVAL);
22260824 253
7f9b3266
SS
254 /* First check if the label is not in the open_outputs list */
255 match = extract_inout(name, open_outputs);
cf4f7d38 256
f219eee5 257 if (match) {
64fbf5e2 258 av_free(name);
0de3407b
VS
259 } else {
260 /* Not in the list, so add it as an input */
00b3ca3c
SS
261 if (!(match = av_mallocz(sizeof(AVFilterInOut))))
262 return AVERROR(ENOMEM);
c880791f 263 match->name = name;
c880791f 264 match->pad_idx = pad;
cf4f7d38 265 }
e97908ee 266
7f9b3266 267 insert_inout(curr_inputs, match);
e97908ee 268
fd548e5b 269 *buf += strspn(*buf, WHITESPACES);
c9987633 270 pad++;
27afb09d 271 }
cf4f7d38 272
27afb09d
VS
273 return pad;
274}
275
7f9b3266
SS
276static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
277 AVFilterInOut **open_inputs,
278 AVFilterInOut **open_outputs, AVClass *log_ctx)
9710beaf 279{
0cc8b659 280 int ret, pad = 0;
c9987633 281
f219eee5 282 while (**buf == '[') {
bd80b349 283 char *name = parse_link_name(buf, log_ctx);
c9987633
VS
284 AVFilterInOut *match;
285
7f9b3266
SS
286 AVFilterInOut *input = *curr_inputs;
287 *curr_inputs = (*curr_inputs)->next;
443c10ef 288
f219eee5 289 if (!name)
0cc8b659 290 return AVERROR(EINVAL);
c9987633 291
7f9b3266
SS
292 /* First check if the label is not in the open_inputs list */
293 match = extract_inout(name, open_inputs);
c9987633 294
f219eee5 295 if (match) {
0cc8b659
SS
296 if ((ret = link_filter(input->filter, input->pad_idx,
297 match->filter, match->pad_idx, log_ctx)) < 0)
298 return ret;
64b164f4
VS
299 av_free(match->name);
300 av_free(name);
c9987633 301 av_free(match);
7baa6210 302 av_free(input);
0de3407b 303 } else {
7f9b3266 304 /* Not in the list, so add the first input as a open_output */
7baa6210 305 input->name = name;
7f9b3266 306 insert_inout(open_outputs, input);
c9987633 307 }
fd548e5b 308 *buf += strspn(*buf, WHITESPACES);
c9987633 309 pad++;
8095a014 310 }
9710beaf 311
c9987633
VS
312 return pad;
313}
9710beaf 314
86a47378 315int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
7f9b3266
SS
316 AVFilterInOut *open_inputs,
317 AVFilterInOut *open_outputs, AVClass *log_ctx)
27afb09d 318{
27afb09d
VS
319 int index = 0;
320 char chr = 0;
27afb09d 321
7f9b3266 322 AVFilterInOut *curr_inputs = NULL;
27afb09d 323
27afb09d 324 do {
9710beaf 325 AVFilterContext *filter;
fd548e5b 326 filters += strspn(filters, WHITESPACES);
27afb09d 327
f219eee5 328 if (parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx) < 0)
27afb09d
VS
329 goto fail;
330
688b9dad 331 if (parse_filter(&filter, &filters, graph, index, log_ctx) < 0)
22260824
VS
332 goto fail;
333
f219eee5 334 if (filter->input_count == 1 && !curr_inputs && !index) {
e916c2ac 335 /* First input can be omitted if it is "[in]" */
c9987633 336 const char *tmp = "[in]";
7f9b3266 337 if(parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx) < 0)
27afb09d 338 goto fail;
27afb09d
VS
339 }
340
f219eee5 341 if (link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx) < 0)
c9987633 342 goto fail;
da790674 343
f219eee5 344 if (parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
e2b5fdaf 345 log_ctx) < 0)
e84f0b62
VS
346 goto fail;
347
fd548e5b 348 filters += strspn(filters, WHITESPACES);
27afb09d 349 chr = *filters++;
27afb09d 350
f219eee5 351 if (chr == ';' && curr_inputs) {
c9987633
VS
352 av_log(log_ctx, AV_LOG_ERROR,
353 "Could not find a output to link when parsing \"%s\"\n",
354 filters - 1);
355 goto fail;
27afb09d 356 }
c9987633 357 index++;
f219eee5 358 } while (chr == ',' || chr == ';');
27afb09d 359
fd51ff16 360 if (chr) {
78471234
SS
361 av_log(log_ctx, AV_LOG_ERROR,
362 "Unable to parse graph description substring: \"%s\"\n",
363 filters - 1);
364 goto fail;
365 }
366
f219eee5 367 if (open_inputs && !strcmp(open_inputs->name, "out") && curr_inputs) {
e916c2ac 368 /* Last output can be omitted if it is "[out]" */
c9987633 369 const char *tmp = "[out]";
f219eee5 370 if (parse_outputs(&tmp, &curr_inputs, &open_inputs,
7f9b3266 371 &open_outputs, log_ctx) < 0)
27afb09d 372 goto fail;
27afb09d
VS
373 }
374
375 return 0;
376
377 fail:
97dd1e4a 378 avfilter_graph_free(graph);
7f9b3266
SS
379 free_inout(open_inputs);
380 free_inout(open_outputs);
381 free_inout(curr_inputs);
27afb09d
VS
382 return -1;
383}