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 const AVClass *av_class;
30 unsigned filter_count;
31 AVFilterContext **filters;
33 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
38 * The following fields are for internal use only.
39 * Their type, offset, number and semantic can change without notice.
42 AVFilterLink **sink_links;
45 unsigned disable_auto_convert;
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 * Enable or disable automatic format conversion inside the graph.
89 * Note that format conversion can still happen inside explicitly inserted
90 * scale and aconvert filters.
92 * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
94 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
97 AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
98 AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
102 * Check validity and configure all the links and formats in the graph.
104 * @param graphctx the filter graph
105 * @param log_ctx context used for logging
106 * @return 0 in case of success, a negative AVERROR code otherwise
108 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
111 * Free a graph, destroy its links, and set *graph to NULL.
112 * If *graph is NULL, do nothing.
114 void avfilter_graph_free(AVFilterGraph **graph);
117 * A linked-list of the inputs/outputs of the filter chain.
119 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
120 * where it is used to communicate open (unlinked) inputs and outputs from and
122 * This struct specifies, per each not connected pad contained in the graph, the
123 * filter context and the pad index required for establishing a link.
125 typedef struct AVFilterInOut {
126 /** unique name for this input/output in the list */
129 /** filter context associated to this input/output */
130 AVFilterContext *filter_ctx;
132 /** index of the filt_ctx pad to use for linking */
135 /** next input/input in the list, NULL if this is the last */
136 struct AVFilterInOut *next;
140 * Allocate a single AVFilterInOut entry.
141 * Must be freed with avfilter_inout_free().
142 * @return allocated AVFilterInOut on success, NULL on failure.
144 AVFilterInOut *avfilter_inout_alloc(void);
147 * Free the supplied list of AVFilterInOut and set *inout to NULL.
148 * If *inout is NULL, do nothing.
150 void avfilter_inout_free(AVFilterInOut **inout);
153 * Add a graph described by a string to a graph.
155 * @param graph the filter graph where to link the parsed graph context
156 * @param filters string to be parsed
157 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
158 * If non-NULL, *inputs is updated to contain the list of open inputs
159 * after the parsing, should be freed with avfilter_inout_free().
160 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
161 * If non-NULL, *outputs is updated to contain the list of open outputs
162 * after the parsing, should be freed with avfilter_inout_free().
163 * @return non negative on success, a negative AVERROR code on error
165 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
166 AVFilterInOut **inputs, AVFilterInOut **outputs,
170 * Add a graph described by a string to a graph.
172 * @param[in] graph the filter graph where to link the parsed graph context
173 * @param[in] filters string to be parsed
174 * @param[out] inputs a linked list of all free (unlinked) inputs of the
175 * parsed graph will be returned here. It is to be freed
176 * by the caller using avfilter_inout_free().
177 * @param[out] outputs a linked list of all free (unlinked) outputs of the
178 * parsed graph will be returned here. It is to be freed by the
179 * caller using avfilter_inout_free().
180 * @return zero on success, a negative AVERROR code on error
182 * @note the difference between avfilter_graph_parse2() and
183 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
184 * the lists of inputs and outputs, which therefore must be known before calling
185 * the function. On the other hand, avfilter_graph_parse2() \em returns the
186 * inputs and outputs that are left unlinked after parsing the graph and the
187 * caller then deals with them. Another difference is that in
188 * avfilter_graph_parse(), the inputs parameter describes inputs of the
189 * <em>already existing</em> part of the graph; i.e. from the point of view of
190 * the newly created part, they are outputs. Similarly the outputs parameter
191 * describes outputs of the already existing filters, which are provided as
192 * inputs to the parsed filters.
193 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
194 * whatsoever to already existing parts of the graph and the inputs parameter
195 * will on return contain inputs of the newly parsed part of the graph.
196 * Analogously the outputs parameter will contain outputs of the newly created
199 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
200 AVFilterInOut **inputs,
201 AVFilterInOut **outputs);
205 * Send a command to one or more filter instances.
207 * @param graph the filter graph
208 * @param target the filter(s) to which the command should be sent
209 * "all" sends to all filters
210 * otherwise it can be a filter or filter instance name
211 * which will send the command to all matching filters.
212 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
213 * @param arg the argument for the command
214 * @param res a buffer with size res_size where the filter(s) can return a response.
216 * @returns >=0 on success otherwise an error code.
217 * AVERROR(ENOSYS) on unsupported commands
219 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
222 * Queue a command for one or more filter instances.
224 * @param graph the filter graph
225 * @param target the filter(s) to which the command should be sent
226 * "all" sends to all filters
227 * otherwise it can be a filter or filter instance name
228 * which will send the command to all matching filters.
229 * @param cmd the command to sent, for handling simplicity all commands must be alphanummeric only
230 * @param arg the argument for the command
231 * @param ts time at which the command should be sent to the filter
233 * @note As this executes commands after this function returns, no return code
234 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
236 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
240 * Dump a graph into a human-readable string representation.
242 * @param graph the graph to dump
243 * @param options formatting options; currently ignored
244 * @return a string, or NULL in case of memory allocation failure;
245 * the string must be freed using av_free
247 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
250 * Request a frame on the oldest sink link.
252 * If the request returns AVERROR_EOF, try the next.
254 * Note that this function is not meant to be the sole scheduling mechanism
255 * of a filtergraph, only a convenience function to help drain a filtergraph
256 * in a balanced way under normal circumstances.
258 * Also note that AVERROR_EOF does not mean that frames did not arrive on
259 * some of the sinks during the process.
260 * When there are multiple sink links, in case the requested link
261 * returns an EOF, this may cause a filter to flush pending frames
262 * which are sent to another sink link, although unrequested.
264 * @return the return value of ff_request_frame(),
265 * or AVERROR_EOF if all links returned AVERROR_EOF
267 int avfilter_graph_request_oldest(AVFilterGraph *graph);
269 #endif /* AVFILTER_AVFILTERGRAPH_H */