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
35 char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
40 * The following fields are for internal use only.
41 * Their type, offset, number and semantic can change without notice.
44 AVFilterLink **sink_links;
47 unsigned disable_auto_convert;
51 * Allocate a filter graph.
53 AVFilterGraph *avfilter_graph_alloc(void);
56 * Get a filter instance with name name from graph.
58 * @return the pointer to the found filter instance or NULL if it
61 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
64 * Add an existing filter instance to a filter graph.
66 * @param graphctx the filter graph
67 * @param filter the filter to be added
69 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
72 * Create and add a filter instance into an existing graph.
73 * The filter instance is created from the filter filt and inited
74 * with the parameters args and opaque.
76 * In case of success put in *filt_ctx the pointer to the created
77 * filter instance, otherwise set *filt_ctx to NULL.
79 * @param name the instance name to give to the created filter instance
80 * @param graph_ctx the filter graph
81 * @return a negative AVERROR error code in case of failure, a non
82 * negative value otherwise
84 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
85 const char *name, const char *args, void *opaque,
86 AVFilterGraph *graph_ctx);
89 * Enable or disable automatic format conversion inside the graph.
91 * Note that format conversion can still happen inside explicitly inserted
92 * scale and aconvert filters.
94 * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
96 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
99 AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
100 AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
104 * Check validity and configure all the links and formats in the graph.
106 * @param graphctx the filter graph
107 * @param log_ctx context used for logging
108 * @return 0 in case of success, a negative AVERROR code otherwise
110 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
113 * Free a graph, destroy its links, and set *graph to NULL.
114 * If *graph is NULL, do nothing.
116 void avfilter_graph_free(AVFilterGraph **graph);
119 * A linked-list of the inputs/outputs of the filter chain.
121 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
122 * where it is used to communicate open (unlinked) inputs and outputs from and
124 * This struct specifies, per each not connected pad contained in the graph, the
125 * filter context and the pad index required for establishing a link.
127 typedef struct AVFilterInOut {
128 /** unique name for this input/output in the list */
131 /** filter context associated to this input/output */
132 AVFilterContext *filter_ctx;
134 /** index of the filt_ctx pad to use for linking */
137 /** next input/input in the list, NULL if this is the last */
138 struct AVFilterInOut *next;
142 * Allocate a single AVFilterInOut entry.
143 * Must be freed with avfilter_inout_free().
144 * @return allocated AVFilterInOut on success, NULL on failure.
146 AVFilterInOut *avfilter_inout_alloc(void);
149 * Free the supplied list of AVFilterInOut and set *inout to NULL.
150 * If *inout is NULL, do nothing.
152 void avfilter_inout_free(AVFilterInOut **inout);
155 * Add a graph described by a string to a graph.
157 * @param graph the filter graph where to link the parsed graph context
158 * @param filters string to be parsed
159 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
160 * If non-NULL, *inputs is updated to contain the list of open inputs
161 * after the parsing, should be freed with avfilter_inout_free().
162 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
163 * If non-NULL, *outputs is updated to contain the list of open outputs
164 * after the parsing, should be freed with avfilter_inout_free().
165 * @return non negative on success, a negative AVERROR code on error
167 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
168 AVFilterInOut **inputs, AVFilterInOut **outputs,
172 * Add a graph described by a string to a graph.
174 * @param[in] graph the filter graph where to link the parsed graph context
175 * @param[in] filters string to be parsed
176 * @param[out] inputs a linked list of all free (unlinked) inputs of the
177 * parsed graph will be returned here. It is to be freed
178 * by the caller using avfilter_inout_free().
179 * @param[out] outputs a linked list of all free (unlinked) outputs of the
180 * parsed graph will be returned here. It is to be freed by the
181 * caller using avfilter_inout_free().
182 * @return zero on success, a negative AVERROR code on error
184 * @note the difference between avfilter_graph_parse2() and
185 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
186 * the lists of inputs and outputs, which therefore must be known before calling
187 * the function. On the other hand, avfilter_graph_parse2() \em returns the
188 * inputs and outputs that are left unlinked after parsing the graph and the
189 * caller then deals with them. Another difference is that in
190 * avfilter_graph_parse(), the inputs parameter describes inputs of the
191 * <em>already existing</em> part of the graph; i.e. from the point of view of
192 * the newly created part, they are outputs. Similarly the outputs parameter
193 * describes outputs of the already existing filters, which are provided as
194 * inputs to the parsed filters.
195 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
196 * whatsoever to already existing parts of the graph and the inputs parameter
197 * will on return contain inputs of the newly parsed part of the graph.
198 * Analogously the outputs parameter will contain outputs of the newly created
201 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
202 AVFilterInOut **inputs,
203 AVFilterInOut **outputs);
207 * Send a command to 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 alphanumeric only
215 * @param arg the argument for the command
216 * @param res a buffer with size res_size where the filter(s) can return a response.
218 * @returns >=0 on success otherwise an error code.
219 * AVERROR(ENOSYS) on unsupported commands
221 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
224 * Queue a command for one or more filter instances.
226 * @param graph the filter graph
227 * @param target the filter(s) to which the command should be sent
228 * "all" sends to all filters
229 * otherwise it can be a filter or filter instance name
230 * which will send the command to all matching filters.
231 * @param cmd the command to sent, for handling simplicity all commands must be alphanummeric only
232 * @param arg the argument for the command
233 * @param ts time at which the command should be sent to the filter
235 * @note As this executes commands after this function returns, no return code
236 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
238 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
242 * Dump a graph into a human-readable string representation.
244 * @param graph the graph to dump
245 * @param options formatting options; currently ignored
246 * @return a string, or NULL in case of memory allocation failure;
247 * the string must be freed using av_free
249 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
252 * Request a frame on the oldest sink link.
254 * If the request returns AVERROR_EOF, try the next.
256 * Note that this function is not meant to be the sole scheduling mechanism
257 * of a filtergraph, only a convenience function to help drain a filtergraph
258 * in a balanced way under normal circumstances.
260 * Also note that AVERROR_EOF does not mean that frames did not arrive on
261 * some of the sinks during the process.
262 * When there are multiple sink links, in case the requested link
263 * returns an EOF, this may cause a filter to flush pending frames
264 * which are sent to another sink link, although unrequested.
266 * @return the return value of ff_request_frame(),
267 * or AVERROR_EOF if all links returned AVERROR_EOF
269 int avfilter_graph_request_oldest(AVFilterGraph *graph);
271 #endif /* AVFILTER_AVFILTERGRAPH_H */