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
39 * Allocate a filter graph.
41 AVFilterGraph *avfilter_graph_alloc(void);
44 * Get a filter instance with name name from graph.
46 * @return the pointer to the found filter instance or NULL if it
49 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
52 * Add an existing filter instance to a filter graph.
54 * @param graphctx the filter graph
55 * @param filter the filter to be added
57 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
60 * Create and add a filter instance into an existing graph.
61 * The filter instance is created from the filter filt and inited
62 * with the parameters args and opaque.
64 * In case of success put in *filt_ctx the pointer to the created
65 * filter instance, otherwise set *filt_ctx to NULL.
67 * @param name the instance name to give to the created filter instance
68 * @param graph_ctx the filter graph
69 * @return a negative AVERROR error code in case of failure, a non
70 * negative value otherwise
72 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
73 const char *name, const char *args, void *opaque,
74 AVFilterGraph *graph_ctx);
77 * Check validity and configure all the links and formats in the graph.
79 * @param graphctx the filter graph
80 * @param log_ctx context used for logging
81 * @return 0 in case of success, a negative AVERROR code otherwise
83 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
86 * Free a graph, destroy its links, and set *graph to NULL.
87 * If *graph is NULL, do nothing.
89 void avfilter_graph_free(AVFilterGraph **graph);
92 * A linked-list of the inputs/outputs of the filter chain.
94 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
95 * where it is used to communicate open (unlinked) inputs and outputs from and
97 * This struct specifies, per each not connected pad contained in the graph, the
98 * filter context and the pad index required for establishing a link.
100 typedef struct AVFilterInOut {
101 /** unique name for this input/output in the list */
104 /** filter context associated to this input/output */
105 AVFilterContext *filter_ctx;
107 /** index of the filt_ctx pad to use for linking */
110 /** next input/input in the list, NULL if this is the last */
111 struct AVFilterInOut *next;
115 * Allocate a single AVFilterInOut entry.
116 * Must be freed with avfilter_inout_free().
117 * @return allocated AVFilterInOut on success, NULL on failure.
119 AVFilterInOut *avfilter_inout_alloc(void);
122 * Free the supplied list of AVFilterInOut and set *inout to NULL.
123 * If *inout is NULL, do nothing.
125 void avfilter_inout_free(AVFilterInOut **inout);
128 * Add a graph described by a string to a graph.
130 * @param graph the filter graph where to link the parsed graph context
131 * @param filters string to be parsed
132 * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
133 * If non-NULL, *inputs is updated to contain the list of open inputs
134 * after the parsing, should be freed with avfilter_inout_free().
135 * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
136 * If non-NULL, *outputs is updated to contain the list of open outputs
137 * after the parsing, should be freed with avfilter_inout_free().
138 * @return non negative on success, a negative AVERROR code on error
140 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
141 AVFilterInOut **inputs, AVFilterInOut **outputs,
145 * Add a graph described by a string to a graph.
147 * @param[in] graph the filter graph where to link the parsed graph context
148 * @param[in] filters string to be parsed
149 * @param[out] inputs a linked list of all free (unlinked) inputs of the
150 * parsed graph will be returned here. It is to be freed
151 * by the caller using avfilter_inout_free().
152 * @param[out] outputs a linked list of all free (unlinked) outputs of the
153 * parsed graph will be returned here. It is to be freed by the
154 * caller using avfilter_inout_free().
155 * @return zero on success, a negative AVERROR code on error
157 * @note the difference between avfilter_graph_parse2() and
158 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
159 * the lists of inputs and outputs, which therefore must be known before calling
160 * the function. On the other hand, avfilter_graph_parse2() \em returns the
161 * inputs and outputs that are left unlinked after parsing the graph and the
162 * caller then deals with them. Another difference is that in
163 * avfilter_graph_parse(), the inputs parameter describes inputs of the
164 * <em>already existing</em> part of the graph; i.e. from the point of view of
165 * the newly created part, they are outputs. Similarly the outputs parameter
166 * describes outputs of the already existing filters, which are provided as
167 * inputs to the parsed filters.
168 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
169 * whatsoever to already existing parts of the graph and the inputs parameter
170 * will on return contain inputs of the newly parsed part of the graph.
171 * Analogously the outputs parameter will contain outputs of the newly created
174 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
175 AVFilterInOut **inputs,
176 AVFilterInOut **outputs);
180 * Send a command to one or more filter instances.
182 * @param graph the filter graph
183 * @param target the filter(s) to which the command should be sent
184 * "all" sends to all filters
185 * otherwise it can be a filter or filter instance name
186 * which will send the command to all matching filters.
187 * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
188 * @param arg the argument for the command
189 * @param res a buffer with size res_size where the filter(s) can return a response.
191 * @returns >=0 on success otherwise an error code.
192 * AVERROR(ENOSYS) on unsupported commands
194 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
197 * Queue a command for one or more filter instances.
199 * @param graph the filter graph
200 * @param target the filter(s) to which the command should be sent
201 * "all" sends to all filters
202 * otherwise it can be a filter or filter instance name
203 * which will send the command to all matching filters.
204 * @param cmd the command to sent, for handling simplicity all commands must be alphanummeric only
205 * @param arg the argument for the command
206 * @param ts time at which the command should be sent to the filter
208 * @note As this executes commands after this function returns, no return code
209 * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
211 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
215 * Dump a graph into a human-readable string representation.
217 * @param graph the graph to dump
218 * @param options formatting options; currently ignored
219 * @return a string, or NULL in case of memory allocation failure;
220 * the string must be freed using av_free
222 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
224 #endif /* AVFILTER_AVFILTERGRAPH_H */