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;
32 unsigned filter_count_unused;
34 AVFilterContext **filters;
39 char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
40 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
44 char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
49 * The following fields are for internal use only.
50 * Their type, offset, number and semantic can change without notice.
53 AVFilterLink **sink_links;
56 unsigned disable_auto_convert;
60 * Allocate a filter graph.
62 AVFilterGraph *avfilter_graph_alloc(void);
65 * Get a filter instance with name name from graph.
67 * @return the pointer to the found filter instance or NULL if it
70 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
73 * Add an existing filter instance to a filter graph.
75 * @param graphctx the filter graph
76 * @param filter the filter to be added
78 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
81 * Create and add a filter instance into an existing graph.
82 * The filter instance is created from the filter filt and inited
83 * with the parameters args and opaque.
85 * In case of success put in *filt_ctx the pointer to the created
86 * filter instance, otherwise set *filt_ctx to NULL.
88 * @param name the instance name to give to the created filter instance
89 * @param graph_ctx the filter graph
90 * @return a negative AVERROR error code in case of failure, a non
91 * negative value otherwise
93 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
94 const char *name, const char *args, void *opaque,
95 AVFilterGraph *graph_ctx);
98 * Enable or disable automatic format conversion inside the graph.
100 * Note that format conversion can still happen inside explicitly inserted
101 * scale and aresample filters.
103 * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
105 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
108 AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
109 AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
113 * Check validity and configure all the links and formats in the graph.
115 * @param graphctx the filter graph
116 * @param log_ctx context used for logging
117 * @return 0 in case of success, a negative AVERROR code otherwise
119 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
122 * Free a graph, destroy its links, and set *graph to NULL.
123 * If *graph is NULL, do nothing.
125 void avfilter_graph_free(AVFilterGraph **graph);
128 * A linked-list of the inputs/outputs of the filter chain.
130 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
131 * where it is used to communicate open (unlinked) inputs and outputs from and
133 * This struct specifies, per each not connected pad contained in the graph, the
134 * filter context and the pad index required for establishing a link.
136 typedef struct AVFilterInOut {
137 /** unique name for this input/output in the list */
140 /** filter context associated to this input/output */
141 AVFilterContext *filter_ctx;
143 /** index of the filt_ctx pad to use for linking */
146 /** next input/input in the list, NULL if this is the last */
147 struct AVFilterInOut *next;
151 * Allocate a single AVFilterInOut entry.
152 * Must be freed with avfilter_inout_free().
153 * @return allocated AVFilterInOut on success, NULL on failure.
155 AVFilterInOut *avfilter_inout_alloc(void);
158 * Free the supplied list of AVFilterInOut and set *inout to NULL.
159 * If *inout is NULL, do nothing.
161 void avfilter_inout_free(AVFilterInOut **inout);
164 * Add a graph described by a string to a graph.
166 * @param graph the filter graph where to link the parsed graph context
167 * @param filters string to be parsed
168 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
169 * If non-NULL, *inputs is updated to contain the list of open inputs
170 * after the parsing, should be freed with avfilter_inout_free().
171 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
172 * If non-NULL, *outputs is updated to contain the list of open outputs
173 * after the parsing, should be freed with avfilter_inout_free().
174 * @return non negative on success, a negative AVERROR code on error
176 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
177 AVFilterInOut **inputs, AVFilterInOut **outputs,
181 * Add a graph described by a string to a graph.
183 * @param[in] graph the filter graph where to link the parsed graph context
184 * @param[in] filters string to be parsed
185 * @param[out] inputs a linked list of all free (unlinked) inputs of the
186 * parsed graph will be returned here. It is to be freed
187 * by the caller using avfilter_inout_free().
188 * @param[out] outputs a linked list of all free (unlinked) outputs of the
189 * parsed graph will be returned here. It is to be freed by the
190 * caller using avfilter_inout_free().
191 * @return zero on success, a negative AVERROR code on error
193 * @note the difference between avfilter_graph_parse2() and
194 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
195 * the lists of inputs and outputs, which therefore must be known before calling
196 * the function. On the other hand, avfilter_graph_parse2() \em returns the
197 * inputs and outputs that are left unlinked after parsing the graph and the
198 * caller then deals with them. Another difference is that in
199 * avfilter_graph_parse(), the inputs parameter describes inputs of the
200 * <em>already existing</em> part of the graph; i.e. from the point of view of
201 * the newly created part, they are outputs. Similarly the outputs parameter
202 * describes outputs of the already existing filters, which are provided as
203 * inputs to the parsed filters.
204 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
205 * whatsoever to already existing parts of the graph and the inputs parameter
206 * will on return contain inputs of the newly parsed part of the graph.
207 * Analogously the outputs parameter will contain outputs of the newly created
210 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
211 AVFilterInOut **inputs,
212 AVFilterInOut **outputs);
216 * Send a command to one or more filter instances.
218 * @param graph the filter graph
219 * @param target the filter(s) to which the command should be sent
220 * "all" sends to all filters
221 * otherwise it can be a filter or filter instance name
222 * which will send the command to all matching filters.
223 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
224 * @param arg the argument for the command
225 * @param res a buffer with size res_size where the filter(s) can return a response.
227 * @returns >=0 on success otherwise an error code.
228 * AVERROR(ENOSYS) on unsupported commands
230 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
233 * Queue a command for one or more filter instances.
235 * @param graph the filter graph
236 * @param target the filter(s) to which the command should be sent
237 * "all" sends to all filters
238 * otherwise it can be a filter or filter instance name
239 * which will send the command to all matching filters.
240 * @param cmd the command to sent, for handling simplicity all commands must be alphanummeric only
241 * @param arg the argument for the command
242 * @param ts time at which the command should be sent to the filter
244 * @note As this executes commands after this function returns, no return code
245 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
247 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
251 * Dump a graph into a human-readable string representation.
253 * @param graph the graph to dump
254 * @param options formatting options; currently ignored
255 * @return a string, or NULL in case of memory allocation failure;
256 * the string must be freed using av_free
258 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
261 * Request a frame on the oldest sink link.
263 * If the request returns AVERROR_EOF, try the next.
265 * Note that this function is not meant to be the sole scheduling mechanism
266 * of a filtergraph, only a convenience function to help drain a filtergraph
267 * in a balanced way under normal circumstances.
269 * Also note that AVERROR_EOF does not mean that frames did not arrive on
270 * some of the sinks during the process.
271 * When there are multiple sink links, in case the requested link
272 * returns an EOF, this may cause a filter to flush pending frames
273 * which are sent to another sink link, although unrequested.
275 * @return the return value of ff_request_frame(),
276 * or AVERROR_EOF if all links returned AVERROR_EOF
278 int avfilter_graph_request_oldest(AVFilterGraph *graph);
280 #endif /* AVFILTER_AVFILTERGRAPH_H */