+ unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
+
+/**
+ * @return AVClass for AVFilterContext.
+ *
+ * @see av_opt_find().
+ */
+const AVClass *avfilter_get_class(void);
+
+typedef struct AVFilterGraphInternal AVFilterGraphInternal;
+
+/**
+ * A function pointer passed to the @ref AVFilterGraph.execute callback to be
+ * executed multiple times, possibly in parallel.
+ *
+ * @param ctx the filter context the job belongs to
+ * @param arg an opaque parameter passed through from @ref
+ * AVFilterGraph.execute
+ * @param jobnr the index of the job being executed
+ * @param nb_jobs the total number of jobs
+ *
+ * @return 0 on success, a negative AVERROR on error
+ */
+typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
+
+/**
+ * A function executing multiple jobs, possibly in parallel.
+ *
+ * @param ctx the filter context to which the jobs belong
+ * @param func the function to be called multiple times
+ * @param arg the argument to be passed to func
+ * @param ret a nb_jobs-sized array to be filled with return values from each
+ * invocation of func
+ * @param nb_jobs the number of jobs to execute
+ *
+ * @return 0 on success, a negative AVERROR on error
+ */
+typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
+ void *arg, int *ret, int nb_jobs);
+
+typedef struct AVFilterGraph {
+ const AVClass *av_class;
+ AVFilterContext **filters;
+ unsigned nb_filters;
+
+ char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
+ char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
+
+ /**
+ * Type of multithreading allowed for filters in this graph. A combination
+ * of AVFILTER_THREAD_* flags.
+ *
+ * May be set by the caller at any point, the setting will apply to all
+ * filters initialized after that. The default is allowing everything.
+ *
+ * When a filter in this graph is initialized, this field is combined using
+ * bit AND with AVFilterContext.thread_type to get the final mask used for
+ * determining allowed threading types. I.e. a threading type needs to be
+ * set in both to be allowed.
+ */
+ int thread_type;
+
+ /**
+ * Maximum number of threads used by filters in this graph. May be set by
+ * the caller before adding any filters to the filtergraph. Zero (the
+ * default) means that the number of threads is determined automatically.
+ */
+ int nb_threads;
+
+ /**
+ * Opaque object for libavfilter internal use.
+ */
+ AVFilterGraphInternal *internal;
+
+ /**
+ * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
+ * be used from callbacks like @ref AVFilterGraph.execute.
+ * Libavfilter will not touch this field in any way.
+ */
+ void *opaque;
+
+ /**
+ * This callback may be set by the caller immediately after allocating the
+ * graph and before adding any filters to it, to provide a custom
+ * multithreading implementation.
+ *
+ * If set, filters with slice threading capability will call this callback
+ * to execute multiple jobs in parallel.
+ *
+ * If this field is left unset, libavfilter will use its internal
+ * implementation, which may or may not be multithreaded depending on the
+ * platform and build options.
+ */
+ avfilter_execute_func *execute;
+} AVFilterGraph;
+
+/**
+ * Allocate a filter graph.
+ *
+ * @return the allocated filter graph on success or NULL.
+ */
+AVFilterGraph *avfilter_graph_alloc(void);
+
+/**
+ * Create a new filter instance in a filter graph.
+ *
+ * @param graph graph in which the new filter will be used
+ * @param filter the filter to create an instance of
+ * @param name Name to give to the new instance (will be copied to
+ * AVFilterContext.name). This may be used by the caller to identify
+ * different filters, libavfilter itself assigns no semantics to
+ * this parameter. May be NULL.
+ *
+ * @return the context of the newly created filter instance (note that it is
+ * also retrievable directly through AVFilterGraph.filters or with
+ * avfilter_graph_get_filter()) on success or NULL or failure.
+ */
+AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
+ const AVFilter *filter,
+ const char *name);
+
+/**
+ * Get a filter instance with name name from graph.
+ *
+ * @return the pointer to the found filter instance or NULL if it
+ * cannot be found.
+ */
+AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name);
+
+#if FF_API_AVFILTER_OPEN
+/**
+ * Add an existing filter instance to a filter graph.
+ *
+ * @param graphctx the filter graph
+ * @param filter the filter to be added
+ *
+ * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
+ * filter graph
+ */
+attribute_deprecated
+int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
+#endif
+
+/**
+ * Create and add a filter instance into an existing graph.
+ * The filter instance is created from the filter filt and inited
+ * with the parameters args and opaque.
+ *
+ * In case of success put in *filt_ctx the pointer to the created
+ * filter instance, otherwise set *filt_ctx to NULL.
+ *
+ * @param name the instance name to give to the created filter instance
+ * @param graph_ctx the filter graph
+ * @return a negative AVERROR error code in case of failure, a non
+ * negative value otherwise
+ */
+int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
+ const char *name, const char *args, void *opaque,
+ AVFilterGraph *graph_ctx);
+
+/**
+ * Check validity and configure all the links and formats in the graph.
+ *
+ * @param graphctx the filter graph
+ * @param log_ctx context used for logging
+ * @return 0 in case of success, a negative AVERROR code otherwise
+ */
+int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
+
+/**
+ * Free a graph, destroy its links, and set *graph to NULL.
+ * If *graph is NULL, do nothing.
+ */
+void avfilter_graph_free(AVFilterGraph **graph);
+
+/**
+ * A linked-list of the inputs/outputs of the filter chain.
+ *
+ * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
+ * where it is used to communicate open (unlinked) inputs and outputs from and
+ * to the caller.
+ * This struct specifies, per each not connected pad contained in the graph, the
+ * filter context and the pad index required for establishing a link.
+ */
+typedef struct AVFilterInOut {
+ /** unique name for this input/output in the list */
+ char *name;
+
+ /** filter context associated to this input/output */
+ AVFilterContext *filter_ctx;
+
+ /** index of the filt_ctx pad to use for linking */
+ int pad_idx;
+
+ /** next input/input in the list, NULL if this is the last */
+ struct AVFilterInOut *next;
+} AVFilterInOut;
+
+/**
+ * Allocate a single AVFilterInOut entry.
+ * Must be freed with avfilter_inout_free().
+ * @return allocated AVFilterInOut on success, NULL on failure.
+ */
+AVFilterInOut *avfilter_inout_alloc(void);
+
+/**
+ * Free the supplied list of AVFilterInOut and set *inout to NULL.
+ * If *inout is NULL, do nothing.
+ */
+void avfilter_inout_free(AVFilterInOut **inout);
+
+/**
+ * Add a graph described by a string to a graph.
+ *
+ * @param graph the filter graph where to link the parsed graph context
+ * @param filters string to be parsed
+ * @param inputs linked list to the inputs of the graph
+ * @param outputs linked list to the outputs of the graph
+ * @return zero on success, a negative AVERROR code on error
+ */
+int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
+ AVFilterInOut *inputs, AVFilterInOut *outputs,
+ void *log_ctx);
+
+/**
+ * Add a graph described by a string to a graph.
+ *
+ * @param[in] graph the filter graph where to link the parsed graph context
+ * @param[in] filters string to be parsed
+ * @param[out] inputs a linked list of all free (unlinked) inputs of the
+ * parsed graph will be returned here. It is to be freed
+ * by the caller using avfilter_inout_free().
+ * @param[out] outputs a linked list of all free (unlinked) outputs of the
+ * parsed graph will be returned here. It is to be freed by the
+ * caller using avfilter_inout_free().
+ * @return zero on success, a negative AVERROR code on error
+ *
+ * @note the difference between avfilter_graph_parse2() and
+ * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides
+ * the lists of inputs and outputs, which therefore must be known before calling
+ * the function. On the other hand, avfilter_graph_parse2() \em returns the
+ * inputs and outputs that are left unlinked after parsing the graph and the
+ * caller then deals with them. Another difference is that in
+ * avfilter_graph_parse(), the inputs parameter describes inputs of the
+ * <em>already existing</em> part of the graph; i.e. from the point of view of
+ * the newly created part, they are outputs. Similarly the outputs parameter
+ * describes outputs of the already existing filters, which are provided as
+ * inputs to the parsed filters.
+ * avfilter_graph_parse2() takes the opposite approach -- it makes no reference
+ * whatsoever to already existing parts of the graph and the inputs parameter
+ * will on return contain inputs of the newly parsed part of the graph.
+ * Analogously the outputs parameter will contain outputs of the newly created
+ * filters.
+ */
+int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
+ AVFilterInOut **inputs,
+ AVFilterInOut **outputs);
+
+/**
+ * @}
+ */
+
+#endif /* AVFILTER_AVFILTER_H */