ffmpeg/libavfilter/avfiltergraph.h

189 lines
6.8 KiB
C

/*
* 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 {
#if FF_API_GRAPH_AVCLASS
const AVClass *av_class;
#endif
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;
/**
* Create an AVFilterInOut.
* Must be free with avfilter_inout_free().
*/
AVFilterInOut *avfilter_inout_alloc(void);
/**
* Free the AVFilterInOut in *inout, and set its pointer 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);
/**
* 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);
#endif /* AVFILTER_AVFILTERGRAPH_H */