FFmpeg/libavfilter/avfiltergraph.h

/*
 * 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 FFMPEG_AVFILTERGRAPH_H
#define FFMPEG_AVFILTERGRAPH_H

#include "avfilter.h"

/** Linked-list of filters to create for an AVFilterGraphDesc */
typedef struct AVFilterGraphDescFilter
{
    int index;              ///< filter instance index
    char *filter;           ///< name of filter type
    char *args;             ///< filter parameters
    struct AVFilterGraphDescFilter *next;
} AVFilterGraphDescFilter;

/** Linked-list of links between filters */
typedef struct AVFilterGraphDescLink
{
    /* TODO: allow referencing pads by name, not just by index */
    int src;                ///< index of the source filter
    unsigned srcpad;        ///< index of the output pad on the source filter

    int dst;                ///< index of the dest filter
    unsigned dstpad;        ///< index of the input pad on the dest filter

    struct AVFilterGraphDescLink *next;
} AVFilterGraphDescLink;

/** Linked-list of filter pads to be exported from the graph */
typedef struct AVFilterGraphDescExport
{
    /* TODO: allow referencing pads by name, not just by index */
    char *name;             ///< name of the exported pad
    int filter;             ///< index of the filter
    unsigned pad;           ///< index of the pad to be exported

    struct AVFilterGraphDescExport *next;
} AVFilterGraphDescExport;

/** Description of a graph to be loaded from a file, etc */
typedef struct
{
    AVFilterGraphDescFilter *filters;   ///< filters in the graph
    AVFilterGraphDescLink   *links;     ///< links between the filters
    AVFilterGraphDescExport *inputs;    ///< inputs to export
    AVFilterGraphDescExport *outputs;   ///< outputs to export
} AVFilterGraphDesc;

typedef struct AVFilterGraph {
    unsigned filter_count;
    AVFilterContext **filters;
} AVFilterGraph;

/**
 * Add to a graph a graph described by a string.
 * @param graph   the filter graph where to link the parsed graph context
 * @param filters string to be parsed
 * @param in      input to the graph to be parsed (TODO: allow several)
 * @param inpad   pad index of the input
 * @param in      output to the graph to be parsed (TODO: allow several)
 * @param inpad   pad index of the output
 * @return        zero on success, -1 on error
 */
int avfilter_graph_parse_chain(AVFilterGraph *graph, const char *filters, AVFilterContext *in, int inpad, AVFilterContext *out, int outpad);

/**
 * Free a filter graph description.
 * @param desc The graph description to free
 */
void avfilter_graph_free_desc(AVFilterGraphDesc *desc);

/**
 * Add an existing filter instance to a filter graph.
 * @param graph  The filter graph
 * @param filter The filter to be added
 */
void avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);

/**
 * Configure the formats of all the links in the graph.
 */
int avfilter_graph_config_formats(AVFilterGraph *graphctx);

/**
 * Configure the parameters (resolution, etc) of all links in the graph.
 */
int avfilter_graph_config_links(AVFilterGraph *graphctx);


int graph_load_from_desc3(AVFilterGraph *ctx, AVFilterGraphDesc *desc,
                          AVFilterContext *in, int inpad,
                          AVFilterContext *out, int outpad);

#endif  /* FFMPEG_AVFILTERGRAPH_H */