3 * copyright (c) 2007 Bobby Bingham
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #ifndef AVFILTER_AVFILTERGRAPH_H
23 #define AVFILTER_AVFILTERGRAPH_H
26 #include "libavutil/log.h"
28 typedef struct AVFilterGraph {
29 #if FF_API_GRAPH_AVCLASS
30 const AVClass *av_class;
32 unsigned filter_count;
33 AVFilterContext **filters;
35 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
40 * The following fields are for internal use only.
41 * Their type, offset, number and semantic can change without notice.
44 AVFilterLink **sink_links;
49 * Allocate a filter graph.
51 AVFilterGraph *avfilter_graph_alloc(void);
54 * Get a filter instance with name name from graph.
56 * @return the pointer to the found filter instance or NULL if it
59 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
62 * Add an existing filter instance to a filter graph.
64 * @param graphctx the filter graph
65 * @param filter the filter to be added
67 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
70 * Create and add a filter instance into an existing graph.
71 * The filter instance is created from the filter filt and inited
72 * with the parameters args and opaque.
74 * In case of success put in *filt_ctx the pointer to the created
75 * filter instance, otherwise set *filt_ctx to NULL.
77 * @param name the instance name to give to the created filter instance
78 * @param graph_ctx the filter graph
79 * @return a negative AVERROR error code in case of failure, a non
80 * negative value otherwise
82 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
83 const char *name, const char *args, void *opaque,
84 AVFilterGraph *graph_ctx);
87 * Check validity and configure all the links and formats in the graph.
89 * @param graphctx the filter graph
90 * @param log_ctx context used for logging
91 * @return 0 in case of success, a negative AVERROR code otherwise
93 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
96 * Free a graph, destroy its links, and set *graph to NULL.
97 * If *graph is NULL, do nothing.
99 void avfilter_graph_free(AVFilterGraph **graph);
102 * A linked-list of the inputs/outputs of the filter chain.
104 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
105 * where it is used to communicate open (unlinked) inputs and outputs from and
107 * This struct specifies, per each not connected pad contained in the graph, the
108 * filter context and the pad index required for establishing a link.
110 typedef struct AVFilterInOut {
111 /** unique name for this input/output in the list */
114 /** filter context associated to this input/output */
115 AVFilterContext *filter_ctx;
117 /** index of the filt_ctx pad to use for linking */
120 /** next input/input in the list, NULL if this is the last */
121 struct AVFilterInOut *next;
125 * Allocate a single AVFilterInOut entry.
126 * Must be freed with avfilter_inout_free().
127 * @return allocated AVFilterInOut on success, NULL on failure.
129 AVFilterInOut *avfilter_inout_alloc(void);
132 * Free the supplied list of AVFilterInOut and set *inout to NULL.
133 * If *inout is NULL, do nothing.
135 void avfilter_inout_free(AVFilterInOut **inout);
138 * Add a graph described by a string to a graph.
140 * @param graph the filter graph where to link the parsed graph context
141 * @param filters string to be parsed
142 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
143 * If non-NULL, *inputs is updated to contain the list of open inputs
144 * after the parsing, should be freed with avfilter_inout_free().
145 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
146 * If non-NULL, *outputs is updated to contain the list of open outputs
147 * after the parsing, should be freed with avfilter_inout_free().
148 * @return non negative on success, a negative AVERROR code on error
150 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
151 AVFilterInOut **inputs, AVFilterInOut **outputs,
155 * Add a graph described by a string to a graph.
157 * @param[in] graph the filter graph where to link the parsed graph context
158 * @param[in] filters string to be parsed
159 * @param[out] inputs a linked list of all free (unlinked) inputs of the
160 * parsed graph will be returned here. It is to be freed
161 * by the caller using avfilter_inout_free().
162 * @param[out] outputs a linked list of all free (unlinked) outputs of the
163 * parsed graph will be returned here. It is to be freed by the
164 * caller using avfilter_inout_free().
165 * @return zero on success, a negative AVERROR code on error
167 * @note the difference between avfilter_graph_parse2() and
168 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
169 * the lists of inputs and outputs, which therefore must be known before calling
170 * the function. On the other hand, avfilter_graph_parse2() \em returns the
171 * inputs and outputs that are left unlinked after parsing the graph and the
172 * caller then deals with them. Another difference is that in
173 * avfilter_graph_parse(), the inputs parameter describes inputs of the
174 * <em>already existing</em> part of the graph; i.e. from the point of view of
175 * the newly created part, they are outputs. Similarly the outputs parameter
176 * describes outputs of the already existing filters, which are provided as
177 * inputs to the parsed filters.
178 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
179 * whatsoever to already existing parts of the graph and the inputs parameter
180 * will on return contain inputs of the newly parsed part of the graph.
181 * Analogously the outputs parameter will contain outputs of the newly created
184 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
185 AVFilterInOut **inputs,
186 AVFilterInOut **outputs);
190 * Send a command to one or more filter instances.
192 * @param graph the filter graph
193 * @param target the filter(s) to which the command should be sent
194 * "all" sends to all filters
195 * otherwise it can be a filter or filter instance name
196 * which will send the command to all matching filters.
197 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
198 * @param arg the argument for the command
199 * @param res a buffer with size res_size where the filter(s) can return a response.
201 * @returns >=0 on success otherwise an error code.
202 * AVERROR(ENOSYS) on unsupported commands
204 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
207 * Queue a command for one or more filter instances.
209 * @param graph the filter graph
210 * @param target the filter(s) to which the command should be sent
211 * "all" sends to all filters
212 * otherwise it can be a filter or filter instance name
213 * which will send the command to all matching filters.
214 * @param cmd the command to sent, for handling simplicity all commands must be alphanummeric only
215 * @param arg the argument for the command
216 * @param ts time at which the command should be sent to the filter
218 * @note As this executes commands after this function returns, no return code
219 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
221 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
225 * Dump a graph into a human-readable string representation.
227 * @param graph the graph to dump
228 * @param options formatting options; currently ignored
229 * @return a string, or NULL in case of memory allocation failure;
230 * the string must be freed using av_free
232 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
235 * Request a frame on the oldest sink link.
237 * If the request returns AVERROR_EOF, try the next.
239 * Note that this function is not meant to be the sole scheduling mechanism
240 * of a filtergraph, only a convenience function to help drain a filtergraph
241 * in a balanced way under normal circumstances.
243 * @return the return value of avfilter_request_frame,
244 * or AVERROR_EOF of all links returned AVERROR_EOF.
246 int avfilter_graph_request_oldest(AVFilterGraph *graph);
248 #endif /* AVFILTER_AVFILTERGRAPH_H */