Remove graphparser.h header, move AVFilterInOut and
[libav.git] / libavfilter / graphparser.c
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
26 #include "libavutil/avstring.h"
27 #include "avfilter.h"
28 #include "avfiltergraph.h"
29 #include "parseutils.h"
30
31 #define WHITESPACES " \n\t"
32
33 /**
34 * Link two filters together.
35 *
36 * @see avfilter_link()
37 */
38 static int link_filter(AVFilterContext *src, int srcpad,
39 AVFilterContext *dst, int dstpad,
40 AVClass *log_ctx)
41 {
42 int ret;
43 if ((ret = avfilter_link(src, srcpad, dst, dstpad))) {
44 av_log(log_ctx, AV_LOG_ERROR,
45 "Cannot create the link %s:%d -> %s:%d\n",
46 src->filter->name, srcpad, dst->filter->name, dstpad);
47 return ret;
48 }
49
50 return 0;
51 }
52
53 /**
54 * Parse the name of a link, which has the format "[linkname]".
55 *
56 * @return a pointer (that need to be freed after use) to the name
57 * between parenthesis
58 */
59 static char *parse_link_name(const char **buf, AVClass *log_ctx)
60 {
61 const char *start = *buf;
62 char *name;
63 (*buf)++;
64
65 name = av_get_token(buf, "]");
66
67 if (!name[0]) {
68 av_log(log_ctx, AV_LOG_ERROR,
69 "Bad (empty?) label found in the following: \"%s\".\n", start);
70 goto fail;
71 }
72
73 if (*(*buf)++ != ']') {
74 av_log(log_ctx, AV_LOG_ERROR,
75 "Mismatched '[' found in the following: \"%s\".\n", start);
76 fail:
77 av_freep(&name);
78 }
79
80 return name;
81 }
82
83 /**
84 * Create an instance of a filter, initialize and insert it in the
85 * filtergraph in *ctx.
86 *
87 * @param ctx the filtergraph context
88 * @param put here a filter context in case of successful creation and configuration, NULL otherwise.
89 * @param index an index which is supposed to be unique for each filter instance added to the filtergraph
90 * @param filt_name the name of the filter to create
91 * @param args the arguments provided to the filter during its initialization
92 * @param log_ctx the log context to use
93 * @return 0 in case of success, a negative AVERROR code otherwise
94 */
95 static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index,
96 const char *filt_name, const char *args, AVClass *log_ctx)
97 {
98 AVFilter *filt;
99 char inst_name[30];
100 char tmp_args[256];
101 int ret;
102
103 snprintf(inst_name, sizeof(inst_name), "Filter %d %s", index, filt_name);
104
105 filt = avfilter_get_by_name(filt_name);
106
107 if (!filt) {
108 av_log(log_ctx, AV_LOG_ERROR,
109 "No such filter: '%s'\n", filt_name);
110 return AVERROR(EINVAL);
111 }
112
113 ret = avfilter_open(filt_ctx, filt, inst_name);
114 if (!*filt_ctx) {
115 av_log(log_ctx, AV_LOG_ERROR,
116 "Error creating filter '%s'\n", filt_name);
117 return ret;
118 }
119
120 if ((ret = avfilter_graph_add_filter(ctx, *filt_ctx)) < 0) {
121 avfilter_destroy(*filt_ctx);
122 return ret;
123 }
124
125 if (!strcmp(filt_name, "scale") && !strstr(args, "flags")) {
126 snprintf(tmp_args, sizeof(tmp_args), "%s:%s",
127 args, ctx->scale_sws_opts);
128 args = tmp_args;
129 }
130
131 if ((ret = avfilter_init_filter(*filt_ctx, args, NULL)) < 0) {
132 av_log(log_ctx, AV_LOG_ERROR,
133 "Error initializing filter '%s' with args '%s'\n", filt_name, args);
134 return ret;
135 }
136
137 return 0;
138 }
139
140 /**
141 * Parse a string of the form FILTER_NAME[=PARAMS], and create a
142 * corresponding filter instance which is added to graph with
143 * create_filter().
144 *
145 * @param filt_ctx put here a pointer to the created filter context on
146 * success, NULL otherwise
147 * @param buf pointer to the buffer to parse, *buf will be updated to
148 * point to the char next after the parsed string
149 * @param index an index which is assigned to the created filter
150 * instance, and which is supposed to be unique for each filter
151 * instance added to the filtergraph
152 * @return 0 in case of success, a negative AVERROR code otherwise
153 */
154 static int parse_filter(AVFilterContext **filt_ctx, const char **buf, AVFilterGraph *graph,
155 int index, AVClass *log_ctx)
156 {
157 char *opts = NULL;
158 char *name = av_get_token(buf, "=,;[\n");
159 int ret;
160
161 if (**buf == '=') {
162 (*buf)++;
163 opts = av_get_token(buf, "[],;\n");
164 }
165
166 ret = create_filter(filt_ctx, graph, index, name, opts, log_ctx);
167 av_free(name);
168 av_free(opts);
169 return ret;
170 }
171
172 static void free_inout(AVFilterInOut *head)
173 {
174 while (head) {
175 AVFilterInOut *next = head->next;
176 av_free(head->name);
177 av_free(head);
178 head = next;
179 }
180 }
181
182 static AVFilterInOut *extract_inout(const char *label, AVFilterInOut **links)
183 {
184 AVFilterInOut *ret;
185
186 while (*links && strcmp((*links)->name, label))
187 links = &((*links)->next);
188
189 ret = *links;
190
191 if (ret)
192 *links = ret->next;
193
194 return ret;
195 }
196
197 static void insert_inout(AVFilterInOut **inouts, AVFilterInOut *element)
198 {
199 element->next = *inouts;
200 *inouts = element;
201 }
202
203 static int link_filter_inouts(AVFilterContext *filt_ctx,
204 AVFilterInOut **curr_inputs,
205 AVFilterInOut **open_inputs, AVClass *log_ctx)
206 {
207 int pad = filt_ctx->input_count, ret;
208
209 while (pad--) {
210 AVFilterInOut *p = *curr_inputs;
211 if (!p) {
212 av_log(log_ctx, AV_LOG_ERROR,
213 "Not enough inputs specified for the \"%s\" filter.\n",
214 filt_ctx->filter->name);
215 return AVERROR(EINVAL);
216 }
217
218 *curr_inputs = (*curr_inputs)->next;
219
220 if (p->filter_ctx) {
221 if ((ret = link_filter(p->filter_ctx, p->pad_idx, filt_ctx, pad, log_ctx)) < 0)
222 return ret;
223 av_free(p->name);
224 av_free(p);
225 } else {
226 p->filter_ctx = filt_ctx;
227 p->pad_idx = pad;
228 insert_inout(open_inputs, p);
229 }
230 }
231
232 if (*curr_inputs) {
233 av_log(log_ctx, AV_LOG_ERROR,
234 "Too many inputs specified for the \"%s\" filter.\n",
235 filt_ctx->filter->name);
236 return AVERROR(EINVAL);
237 }
238
239 pad = filt_ctx->output_count;
240 while (pad--) {
241 AVFilterInOut *currlinkn = av_mallocz(sizeof(AVFilterInOut));
242 if (!currlinkn)
243 return AVERROR(ENOMEM);
244 currlinkn->filter_ctx = filt_ctx;
245 currlinkn->pad_idx = pad;
246 insert_inout(curr_inputs, currlinkn);
247 }
248
249 return 0;
250 }
251
252 static int parse_inputs(const char **buf, AVFilterInOut **curr_inputs,
253 AVFilterInOut **open_outputs, AVClass *log_ctx)
254 {
255 int pad = 0;
256
257 while (**buf == '[') {
258 char *name = parse_link_name(buf, log_ctx);
259 AVFilterInOut *match;
260
261 if (!name)
262 return AVERROR(EINVAL);
263
264 /* First check if the label is not in the open_outputs list */
265 match = extract_inout(name, open_outputs);
266
267 if (match) {
268 av_free(name);
269 } else {
270 /* Not in the list, so add it as an input */
271 if (!(match = av_mallocz(sizeof(AVFilterInOut))))
272 return AVERROR(ENOMEM);
273 match->name = name;
274 match->pad_idx = pad;
275 }
276
277 insert_inout(curr_inputs, match);
278
279 *buf += strspn(*buf, WHITESPACES);
280 pad++;
281 }
282
283 return pad;
284 }
285
286 static int parse_outputs(const char **buf, AVFilterInOut **curr_inputs,
287 AVFilterInOut **open_inputs,
288 AVFilterInOut **open_outputs, AVClass *log_ctx)
289 {
290 int ret, pad = 0;
291
292 while (**buf == '[') {
293 char *name = parse_link_name(buf, log_ctx);
294 AVFilterInOut *match;
295
296 AVFilterInOut *input = *curr_inputs;
297 *curr_inputs = (*curr_inputs)->next;
298
299 if (!name)
300 return AVERROR(EINVAL);
301
302 /* First check if the label is not in the open_inputs list */
303 match = extract_inout(name, open_inputs);
304
305 if (match) {
306 if ((ret = link_filter(input->filter_ctx, input->pad_idx,
307 match->filter_ctx, match->pad_idx, log_ctx)) < 0)
308 return ret;
309 av_free(match->name);
310 av_free(name);
311 av_free(match);
312 av_free(input);
313 } else {
314 /* Not in the list, so add the first input as a open_output */
315 input->name = name;
316 insert_inout(open_outputs, input);
317 }
318 *buf += strspn(*buf, WHITESPACES);
319 pad++;
320 }
321
322 return pad;
323 }
324
325 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
326 AVFilterInOut *open_inputs,
327 AVFilterInOut *open_outputs, AVClass *log_ctx)
328 {
329 int index = 0, ret;
330 char chr = 0;
331
332 AVFilterInOut *curr_inputs = NULL;
333
334 do {
335 AVFilterContext *filter;
336 filters += strspn(filters, WHITESPACES);
337
338 if ((ret = parse_inputs(&filters, &curr_inputs, &open_outputs, log_ctx)) < 0)
339 goto fail;
340
341 if ((ret = parse_filter(&filter, &filters, graph, index, log_ctx)) < 0)
342 goto fail;
343
344 if (filter->input_count == 1 && !curr_inputs && !index) {
345 /* First input can be omitted if it is "[in]" */
346 const char *tmp = "[in]";
347 if ((ret = parse_inputs(&tmp, &curr_inputs, &open_outputs, log_ctx)) < 0)
348 goto fail;
349 }
350
351 if ((ret = link_filter_inouts(filter, &curr_inputs, &open_inputs, log_ctx)) < 0)
352 goto fail;
353
354 if ((ret = parse_outputs(&filters, &curr_inputs, &open_inputs, &open_outputs,
355 log_ctx)) < 0)
356 goto fail;
357
358 filters += strspn(filters, WHITESPACES);
359 chr = *filters++;
360
361 if (chr == ';' && curr_inputs) {
362 av_log(log_ctx, AV_LOG_ERROR,
363 "Could not find a output to link when parsing \"%s\"\n",
364 filters - 1);
365 ret = AVERROR(EINVAL);
366 goto fail;
367 }
368 index++;
369 } while (chr == ',' || chr == ';');
370
371 if (chr) {
372 av_log(log_ctx, AV_LOG_ERROR,
373 "Unable to parse graph description substring: \"%s\"\n",
374 filters - 1);
375 ret = AVERROR(EINVAL);
376 goto fail;
377 }
378
379 if (open_inputs && !strcmp(open_inputs->name, "out") && curr_inputs) {
380 /* Last output can be omitted if it is "[out]" */
381 const char *tmp = "[out]";
382 if ((ret = parse_outputs(&tmp, &curr_inputs, &open_inputs, &open_outputs,
383 log_ctx)) < 0)
384 goto fail;
385 }
386
387 return 0;
388
389 fail:
390 avfilter_graph_free(graph);
391 free_inout(open_inputs);
392 free_inout(open_outputs);
393 free_inout(curr_inputs);
394 return ret;
395 }