/* * Filter graphs * copyright (c) 2007 Bobby Bingham * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVFILTER_AVFILTERGRAPH_H#define AVFILTER_AVFILTERGRAPH_H #include "avfilter.h" typedef struct AVFilterGraph {    unsigned filter_count;    AVFilterContext **filters;     char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters} AVFilterGraph; /** * Allocate a filter graph. */AVFilterGraph *avfilter_graph_alloc(void); /** * 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); /** * Add an existing filter instance to a filter graph. * * @param graphctx  the filter graph * @param filter the filter to be added */int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter); /** * 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, 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(), since this * function may accept a description of a graph with not connected * input/output pads. 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; /** * 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); #endif /* AVFILTER_AVFILTERGRAPH_H */