/*
  * Filter graphs
  * copyright (c) 2007 Bobby Bingham
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg 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.
  *
  * FFmpeg 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 FFmpeg; 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"

 #include "libavutil/log.h"

 typedef struct AVFilterGraph {

     const AVClass *av_class;

     unsigned filter_count;
     AVFilterContext **filters;

 
     char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters

     char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
 

     /**
      * Private fields
      *
      * The following fields are for internal use only.
      * Their type, offset, number and semantic can change without notice.
      */
 
     AVFilterLink **sink_links;
     int sink_links_count;

 
     unsigned disable_auto_convert;

 } 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);
 
 /**

  * Enable or disable automatic format conversion inside the graph.
  *
  * Note that format conversion can still happen inside explicitly inserted
  * scale and aconvert filters.
  *
  * @param flags  any of the AVFILTER_AUTO_CONVERT_* constants
  */
 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
 
 enum {
     AVFILTER_AUTO_CONVERT_ALL  =  0, /**< all automatic conversions enabled */
     AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
 };
 
 /**

  * 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  pointer to a linked list to the inputs of the graph, may be NULL.
  *                If non-NULL, *inputs is updated to contain the list of open inputs
  *                after the parsing, should be freed with avfilter_inout_free().
  * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
  *                If non-NULL, *outputs is updated to contain the list of open outputs
  *                after the parsing, should be freed with avfilter_inout_free().

  * @return non negative 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);
 

 
 /**

  * Send a command to one or more filter instances.
  *
  * @param graph  the filter graph
  * @param target the filter(s) to which the command should be sent
  *               "all" sends to all filters
  *               otherwise it can be a filter or filter instance name
  *               which will send the command to all matching filters.
  * @param cmd    the command to sent, for handling simplicity all commands must be alphanumeric only
  * @param arg    the argument for the command
  * @param res    a buffer with size res_size where the filter(s) can return a response.
  *
  * @returns >=0 on success otherwise an error code.
  *              AVERROR(ENOSYS) on unsupported commands
  */
 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
 

 /**
  * Queue a command for one or more filter instances.
  *
  * @param graph  the filter graph
  * @param target the filter(s) to which the command should be sent
  *               "all" sends to all filters
  *               otherwise it can be a filter or filter instance name
  *               which will send the command to all matching filters.
  * @param cmd    the command to sent, for handling simplicity all commands must be alphanummeric only
  * @param arg    the argument for the command
  * @param ts     time at which the command should be sent to the filter
  *
  * @note As this executes commands after this function returns, no return code
  *       from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
  */
 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
 
 

 /**
  * Dump a graph into a human-readable string representation.
  *
  * @param graph    the graph to dump
  * @param options  formatting options; currently ignored
  * @return  a string, or NULL in case of memory allocation failure;
  *          the string must be freed using av_free
  */
 char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);

 /**
  * Request a frame on the oldest sink link.
  *
  * If the request returns AVERROR_EOF, try the next.
  *
  * Note that this function is not meant to be the sole scheduling mechanism
  * of a filtergraph, only a convenience function to help drain a filtergraph
  * in a balanced way under normal circumstances.
  *

  * Also note that AVERROR_EOF does not mean that frames did not arrive on
  * some of the sinks during the process.
  * When there are multiple sink links, in case the requested link
  * returns an EOF, this may cause a filter to flush pending frames
  * which are sent to another sink link, although unrequested.
  *

  * @return  the return value of ff_request_frame(),
  *          or AVERROR_EOF if all links returned AVERROR_EOF

  */
 int avfilter_graph_request_oldest(AVFilterGraph *graph);
 

 #endif /* AVFILTER_AVFILTERGRAPH_H */