3 * copyright (c) 2007 Bobby Bingham
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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
37 * Allocate a filter graph.
39 AVFilterGraph *avfilter_graph_alloc(void);
42 * Get a filter instance with name name from graph.
44 * @return the pointer to the found filter instance or NULL if it
47 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
50 * Add an existing filter instance to a filter graph.
52 * @param graphctx the filter graph
53 * @param filter the filter to be added
55 int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
58 * Create and add a filter instance into an existing graph.
59 * The filter instance is created from the filter filt and inited
60 * with the parameters args and opaque.
62 * In case of success put in *filt_ctx the pointer to the created
63 * filter instance, otherwise set *filt_ctx to NULL.
65 * @param name the instance name to give to the created filter instance
66 * @param graph_ctx the filter graph
67 * @return a negative AVERROR error code in case of failure, a non
68 * negative value otherwise
70 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
71 const char *name, const char *args, void *opaque,
72 AVFilterGraph *graph_ctx);
75 * Check validity and configure all the links and formats in the graph.
77 * @param graphctx the filter graph
78 * @param log_ctx context used for logging
79 * @return 0 in case of success, a negative AVERROR code otherwise
81 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
84 * Free a graph, destroy its links, and set *graph to NULL.
85 * If *graph is NULL, do nothing.
87 void avfilter_graph_free(AVFilterGraph **graph);
90 * A linked-list of the inputs/outputs of the filter chain.
92 * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
93 * where it is used to communicate open (unlinked) inputs and outputs from and
95 * This struct specifies, per each not connected pad contained in the graph, the
96 * filter context and the pad index required for establishing a link.
98 typedef struct AVFilterInOut {
99 /** unique name for this input/output in the list */
102 /** filter context associated to this input/output */
103 AVFilterContext *filter_ctx;
105 /** index of the filt_ctx pad to use for linking */
108 /** next input/input in the list, NULL if this is the last */
109 struct AVFilterInOut *next;
113 * Allocate a single AVFilterInOut entry.
114 * Must be freed with avfilter_inout_free().
115 * @return allocated AVFilterInOut on success, NULL on failure.
117 AVFilterInOut *avfilter_inout_alloc(void);
120 * Free the supplied list of AVFilterInOut and set *inout to NULL.
121 * If *inout is NULL, do nothing.
123 void avfilter_inout_free(AVFilterInOut **inout);
126 * Add a graph described by a string to a graph.
128 * @param graph the filter graph where to link the parsed graph context
129 * @param filters string to be parsed
130 * @param inputs linked list to the inputs of the graph
131 * @param outputs linked list to the outputs of the graph
132 * @return zero on success, a negative AVERROR code on error
134 int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
135 AVFilterInOut *inputs, AVFilterInOut *outputs,
139 * Add a graph described by a string to a graph.
141 * @param[in] graph the filter graph where to link the parsed graph context
142 * @param[in] filters string to be parsed
143 * @param[out] inputs a linked list of all free (unlinked) inputs of the
144 * parsed graph will be returned here. It is to be freed
145 * by the caller using avfilter_inout_free().
146 * @param[out] outputs a linked list of all free (unlinked) outputs of the
147 * parsed graph will be returned here. It is to be freed by the
148 * caller using avfilter_inout_free().
149 * @return zero on success, a negative AVERROR code on error
151 * @note the difference between avfilter_graph_parse2() and
152 * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
153 * the lists of inputs and outputs, which therefore must be known before calling
154 * the function. On the other hand, avfilter_graph_parse2() \em returns the
155 * inputs and outputs that are left unlinked after parsing the graph and the
156 * caller then deals with them. Another difference is that in
157 * avfilter_graph_parse(), the inputs parameter describes inputs of the
158 * <em>already existing</em> part of the graph; i.e. from the point of view of
159 * the newly created part, they are outputs. Similarly the outputs parameter
160 * describes outputs of the already existing filters, which are provided as
161 * inputs to the parsed filters.
162 * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
163 * whatsoever to already existing parts of the graph and the inputs parameter
164 * will on return contain inputs of the newly parsed part of the graph.
165 * Analogously the outputs parameter will contain outputs of the newly created
168 int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
169 AVFilterInOut **inputs,
170 AVFilterInOut **outputs);
172 #endif /* AVFILTER_AVFILTERGRAPH_H */