Subversion Repositories Kolibri OS

/*

 * filter layer

 * 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_AVFILTER_H

#define AVFILTER_AVFILTER_H

/**

 * @file

 * @ingroup lavfi

 * Main libavfilter public API header

 */

/**

 * @defgroup lavfi Libavfilter - graph-based frame editing library

 * @{

 */

#include 

#include "libavutil/attributes.h"

#include "libavutil/avutil.h"

#include "libavutil/dict.h"

#include "libavutil/frame.h"

#include "libavutil/log.h"

#include "libavutil/samplefmt.h"

#include "libavutil/pixfmt.h"

#include "libavutil/rational.h"

#include "libavfilter/version.h"

/**

 * Return the LIBAVFILTER_VERSION_INT constant.

 */

unsigned avfilter_version(void);

/**

 * Return the libavfilter build-time configuration.

 */

const char *avfilter_configuration(void);

/**

 * Return the libavfilter license.

 */

const char *avfilter_license(void);

typedef struct AVFilterContext AVFilterContext;

typedef struct AVFilterLink    AVFilterLink;

typedef struct AVFilterPad     AVFilterPad;

typedef struct AVFilterFormats AVFilterFormats;

#if FF_API_AVFILTERBUFFER

/**

 * A reference-counted buffer data type used by the filter system. Filters

 * should not store pointers to this structure directly, but instead use the

 * AVFilterBufferRef structure below.

 */

typedef struct AVFilterBuffer {

    uint8_t *data[8];           ///< buffer data for each plane/channel

    /**

     * pointers to the data planes/channels.

     *

     * For video, this should simply point to data[].

     *

     * For planar audio, each channel has a separate data pointer, and

     * linesize[0] contains the size of each channel buffer.

     * For packed audio, there is just one data pointer, and linesize[0]

     * contains the total size of the buffer for all channels.

     *

     * Note: Both data and extended_data will always be set, but for planar

     * audio with more channels that can fit in data, extended_data must be used

     * in order to access all channels.

     */

    uint8_t **extended_data;

    int linesize[8];            ///< number of bytes per line

    /** private data to be used by a custom free function */

    void *priv;

    /**

     * A pointer to the function to deallocate this buffer if the default

     * function is not sufficient. This could, for example, add the memory

     * back into a memory pool to be reused later without the overhead of

     * reallocating it from scratch.

     */

    void (*free)(struct AVFilterBuffer *buf);

    int format;                 ///< media format

    int w, h;                   ///< width and height of the allocated buffer

    unsigned refcount;          ///< number of references to this buffer

} AVFilterBuffer;

#define AV_PERM_READ     0x01   ///< can read from the buffer

#define AV_PERM_WRITE    0x02   ///< can write to the buffer

#define AV_PERM_PRESERVE 0x04   ///< nobody else can overwrite the buffer

#define AV_PERM_REUSE    0x08   ///< can output the buffer multiple times, with the same contents each time

#define AV_PERM_REUSE2   0x10   ///< can output the buffer multiple times, modified each time

#define AV_PERM_NEG_LINESIZES 0x20  ///< the buffer requested can have negative linesizes

#define AV_PERM_ALIGN    0x40   ///< the buffer must be aligned

#define AVFILTER_ALIGN 16 //not part of ABI

/**

 * Audio specific properties in a reference to an AVFilterBuffer. Since

 * AVFilterBufferRef is common to different media formats, audio specific

 * per reference properties must be separated out.

 */

typedef struct AVFilterBufferRefAudioProps {

    uint64_t channel_layout;    ///< channel layout of audio buffer

    int nb_samples;             ///< number of audio samples per channel

    int sample_rate;            ///< audio buffer sample rate

    int channels;               ///< number of channels (do not access directly)

} AVFilterBufferRefAudioProps;

/**

 * Video specific properties in a reference to an AVFilterBuffer. Since

 * AVFilterBufferRef is common to different media formats, video specific

 * per reference properties must be separated out.

 */

typedef struct AVFilterBufferRefVideoProps {

    int w;                      ///< image width

    int h;                      ///< image height

    AVRational sample_aspect_ratio; ///< sample aspect ratio

    int interlaced;             ///< is frame interlaced

    int top_field_first;        ///< field order

    enum AVPictureType pict_type; ///< picture type of the frame

    int key_frame;              ///< 1 -> keyframe, 0-> not

    int qp_table_linesize;                ///< qp_table stride

    int qp_table_size;            ///< qp_table size

    int8_t *qp_table;             ///< array of Quantization Parameters

} AVFilterBufferRefVideoProps;

/**

 * A reference to an AVFilterBuffer. Since filters can manipulate the origin of

 * a buffer to, for example, crop image without any memcpy, the buffer origin

 * and dimensions are per-reference properties. Linesize is also useful for

 * image flipping, frame to field filters, etc, and so is also per-reference.

 *

 * TODO: add anything necessary for frame reordering

 */

typedef struct AVFilterBufferRef {

    AVFilterBuffer *buf;        ///< the buffer that this is a reference to

    uint8_t *data[8];           ///< picture/audio data for each plane

    /**

     * pointers to the data planes/channels.

     *

     * For video, this should simply point to data[].

     *

     * For planar audio, each channel has a separate data pointer, and

     * linesize[0] contains the size of each channel buffer.

     * For packed audio, there is just one data pointer, and linesize[0]

     * contains the total size of the buffer for all channels.

     *

     * Note: Both data and extended_data will always be set, but for planar

     * audio with more channels that can fit in data, extended_data must be used

     * in order to access all channels.

     */

    uint8_t **extended_data;

    int linesize[8];            ///< number of bytes per line

    AVFilterBufferRefVideoProps *video; ///< video buffer specific properties

    AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties

    /**

     * presentation timestamp. The time unit may change during

     * filtering, as it is specified in the link and the filter code

     * may need to rescale the PTS accordingly.

     */

    int64_t pts;

    int64_t pos;                ///< byte position in stream, -1 if unknown

    int format;                 ///< media format

    int perms;                  ///< permissions, see the AV_PERM_* flags

    enum AVMediaType type;      ///< media type of buffer data

    AVDictionary *metadata;     ///< dictionary containing metadata key=value tags

} AVFilterBufferRef;

/**

 * Copy properties of src to dst, without copying the actual data

 */

attribute_deprecated

void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src);

/**

 * Add a new reference to a buffer.

 *

 * @param ref   an existing reference to the buffer

 * @param pmask a bitmask containing the allowable permissions in the new

 *              reference

 * @return      a new reference to the buffer with the same properties as the

 *              old, excluding any permissions denied by pmask

 */

attribute_deprecated

AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);

/**

 * Remove a reference to a buffer. If this is the last reference to the

 * buffer, the buffer itself is also automatically freed.

 *

 * @param ref reference to the buffer, may be NULL

 *

 * @note it is recommended to use avfilter_unref_bufferp() instead of this

 * function

 */

attribute_deprecated

void avfilter_unref_buffer(AVFilterBufferRef *ref);

/**

 * Remove a reference to a buffer and set the pointer to NULL.

 * If this is the last reference to the buffer, the buffer itself

 * is also automatically freed.

 *

 * @param ref pointer to the buffer reference

 */

attribute_deprecated

void avfilter_unref_bufferp(AVFilterBufferRef **ref);

#endif

/**

 * Get the number of channels of a buffer reference.

 */

attribute_deprecated

int avfilter_ref_get_channels(AVFilterBufferRef *ref);

#if FF_API_AVFILTERPAD_PUBLIC

/**

 * A filter pad used for either input or output.

 *

 * See doc/filter_design.txt for details on how to implement the methods.

 *

 * @warning this struct might be removed from public API.

 * users should call avfilter_pad_get_name() and avfilter_pad_get_type()

 * to access the name and type fields; there should be no need to access

 * any other fields from outside of libavfilter.

 */

struct AVFilterPad {

    /**

     * Pad name. The name is unique among inputs and among outputs, but an

     * input may have the same name as an output. This may be NULL if this

     * pad has no need to ever be referenced by name.

     */

    const char *name;

    /**

     * AVFilterPad type.

     */

    enum AVMediaType type;

    /**

     * Input pads:

     * Minimum required permissions on incoming buffers. Any buffer with

     * insufficient permissions will be automatically copied by the filter

     * system to a new buffer which provides the needed access permissions.

     *

     * Output pads:

     * Guaranteed permissions on outgoing buffers. Any buffer pushed on the

     * link must have at least these permissions; this fact is checked by

     * asserts. It can be used to optimize buffer allocation.

     */

    attribute_deprecated int min_perms;

    /**

     * Input pads:

     * Permissions which are not accepted on incoming buffers. Any buffer

     * which has any of these permissions set will be automatically copied

     * by the filter system to a new buffer which does not have those

     * permissions. This can be used to easily disallow buffers with

     * AV_PERM_REUSE.

     *

     * Output pads:

     * Permissions which are automatically removed on outgoing buffers. It

     * can be used to optimize buffer allocation.

     */

    attribute_deprecated int rej_perms;

    /**

     * @deprecated unused

     */

    int (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);

    /**

     * Callback function to get a video buffer. If NULL, the filter system will

     * use ff_default_get_video_buffer().

     *

     * Input video pads only.

     */

    AVFrame *(*get_video_buffer)(AVFilterLink *link, int w, int h);

    /**

     * Callback function to get an audio buffer. If NULL, the filter system will

     * use ff_default_get_audio_buffer().

     *

     * Input audio pads only.

     */

    AVFrame *(*get_audio_buffer)(AVFilterLink *link, int nb_samples);

    /**

     * @deprecated unused

     */

    int (*end_frame)(AVFilterLink *link);

    /**

     * @deprecated unused

     */

    int (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);

    /**

     * Filtering callback. This is where a filter receives a frame with

     * audio/video data and should do its processing.

     *

     * Input pads only.

     *

     * @return >= 0 on success, a negative AVERROR on error. This function

     * must ensure that frame is properly unreferenced on error if it

     * hasn't been passed on to another filter.

     */

    int (*filter_frame)(AVFilterLink *link, AVFrame *frame);

    /**

     * Frame poll callback. This returns the number of immediately available

     * samples. It should return a positive value if the next request_frame()

     * is guaranteed to return one frame (with no delay).

     *

     * Defaults to just calling the source poll_frame() method.

     *

     * Output pads only.

     */

    int (*poll_frame)(AVFilterLink *link);

    /**

     * Frame request callback. A call to this should result in at least one

     * frame being output over the given link. This should return zero on

     * success, and another value on error.

     * See ff_request_frame() for the error codes with a specific

     * meaning.

     *

     * Output pads only.

     */

    int (*request_frame)(AVFilterLink *link);

    /**

     * Link configuration callback.

     *

     * For output pads, this should set the following link properties:

     * video: width, height, sample_aspect_ratio, time_base

     * audio: sample_rate.

     *

     * This should NOT set properties such as format, channel_layout, etc which

     * are negotiated between filters by the filter system using the

     * query_formats() callback before this function is called.

     *

     * For input pads, this should check the properties of the link, and update

     * the filter's internal state as necessary.

     *

     * For both input and output pads, this should return zero on success,

     * and another value on error.

     */

    int (*config_props)(AVFilterLink *link);

    /**

     * The filter expects a fifo to be inserted on its input link,

     * typically because it has a delay.

     *

     * input pads only.

     */

    int needs_fifo;

    int needs_writable;

};

#endif

/**

 * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.

 * AVFilter.inputs/outputs).

 */

int avfilter_pad_count(const AVFilterPad *pads);

/**

 * Get the name of an AVFilterPad.

 *

 * @param pads an array of AVFilterPads

 * @param pad_idx index of the pad in the array it; is the caller's

 *                responsibility to ensure the index is valid

 *

 * @return name of the pad_idx'th pad in pads

 */

const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);

/**

 * Get the type of an AVFilterPad.

 *

 * @param pads an array of AVFilterPads

 * @param pad_idx index of the pad in the array; it is the caller's

 *                responsibility to ensure the index is valid

 *

 * @return type of the pad_idx'th pad in pads

 */

enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);

/**

 * The number of the filter inputs is not determined just by AVFilter.inputs.

 * The filter might add additional inputs during initialization depending on the

 * options supplied to it.

 */

#define AVFILTER_FLAG_DYNAMIC_INPUTS        (1 << 0)

/**

 * The number of the filter outputs is not determined just by AVFilter.outputs.

 * The filter might add additional outputs during initialization depending on

 * the options supplied to it.

 */

#define AVFILTER_FLAG_DYNAMIC_OUTPUTS       (1 << 1)

/**

 * The filter supports multithreading by splitting frames into multiple parts

 * and processing them concurrently.

 */

#define AVFILTER_FLAG_SLICE_THREADS         (1 << 2)

/**

 * Some filters support a generic "enable" expression option that can be used

 * to enable or disable a filter in the timeline. Filters supporting this

 * option have this flag set. When the enable expression is false, the default

 * no-op filter_frame() function is called in place of the filter_frame()

 * callback defined on each input pad, thus the frame is passed unchanged to

 * the next filters.

 */

#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC  (1 << 16)

/**

 * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will

 * have its filter_frame() callback(s) called as usual even when the enable

 * expression is false. The filter will disable filtering within the

 * filter_frame() callback(s) itself, for example executing code depending on

 * the AVFilterContext->is_disabled value.

 */

#define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)

/**

 * Handy mask to test whether the filter supports or no the timeline feature

 * (internally or generically).

 */

#define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)

/**

 * Filter definition. This defines the pads a filter contains, and all the

 * callback functions used to interact with the filter.

 */

typedef struct AVFilter {

    /**

     * Filter name. Must be non-NULL and unique among filters.

     */

    const char *name;

    /**

     * A description of the filter. May be NULL.

     *

     * You should use the NULL_IF_CONFIG_SMALL() macro to define it.

     */

    const char *description;

    /**

     * List of inputs, terminated by a zeroed element.

     *

     * NULL if there are no (static) inputs. Instances of filters with

     * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in

     * this list.

     */

    const AVFilterPad *inputs;

    /**

     * List of outputs, terminated by a zeroed element.

     *

     * NULL if there are no (static) outputs. Instances of filters with

     * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in

     * this list.

     */

    const AVFilterPad *outputs;

    /**

     * A class for the private data, used to declare filter private AVOptions.

     * This field is NULL for filters that do not declare any options.

     *

     * If this field is non-NULL, the first member of the filter private data

     * must be a pointer to AVClass, which will be set by libavfilter generic

     * code to this class.

     */

    const AVClass *priv_class;

    /**

     * A combination of AVFILTER_FLAG_*

     */

    int flags;

    /*****************************************************************

     * All fields below this line are not part of the public API. They

     * may not be used outside of libavfilter and can be changed and

     * removed at will.

     * New public fields should be added right above.

     *****************************************************************

     */

    /**

     * Filter initialization function.

     *

     * This callback will be called only once during the filter lifetime, after

     * all the options have been set, but before links between filters are

     * established and format negotiation is done.

     *

     * Basic filter initialization should be done here. Filters with dynamic

     * inputs and/or outputs should create those inputs/outputs here based on

     * provided options. No more changes to this filter's inputs/outputs can be

     * done after this callback.

     *

     * This callback must not assume that the filter links exist or frame

     * parameters are known.

     *

     * @ref AVFilter.uninit "uninit" is guaranteed to be called even if

     * initialization fails, so this callback does not have to clean up on

     * failure.

     *

     * @return 0 on success, a negative AVERROR on failure

     */

    int (*init)(AVFilterContext *ctx);

    /**

     * Should be set instead of @ref AVFilter.init "init" by the filters that

     * want to pass a dictionary of AVOptions to nested contexts that are

     * allocated during init.

     *

     * On return, the options dict should be freed and replaced with one that

     * contains all the options which could not be processed by this filter (or

     * with NULL if all the options were processed).

     *

     * Otherwise the semantics is the same as for @ref AVFilter.init "init".

     */

    int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);

    /**

     * Filter uninitialization function.

     *

     * Called only once right before the filter is freed. Should deallocate any

     * memory held by the filter, release any buffer references, etc. It does

     * not need to deallocate the AVFilterContext.priv memory itself.

     *

     * This callback may be called even if @ref AVFilter.init "init" was not

     * called or failed, so it must be prepared to handle such a situation.

     */

    void (*uninit)(AVFilterContext *ctx);

    /**

     * Query formats supported by the filter on its inputs and outputs.

     *

     * This callback is called after the filter is initialized (so the inputs

     * and outputs are fixed), shortly before the format negotiation. This

     * callback may be called more than once.

     *

     * This callback must set AVFilterLink.out_formats on every input link and

     * AVFilterLink.in_formats on every output link to a list of pixel/sample

     * formats that the filter supports on that link. For audio links, this

     * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /

     * @ref AVFilterLink.out_samplerates "out_samplerates" and

     * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /

     * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.

     *

     * This callback may be NULL for filters with one input, in which case

     * libavfilter assumes that it supports all input formats and preserves

     * them on output.

     *

     * @return zero on success, a negative value corresponding to an

     * AVERROR code otherwise

     */

    int (*query_formats)(AVFilterContext *);

    int priv_size;      ///< size of private data to allocate for the filter

    /**

     * Used by the filter registration system. Must not be touched by any other

     * code.

     */

    struct AVFilter *next;

    /**

     * Make the filter instance process a command.

     *

     * @param cmd    the command to process, 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. This must not change when the command is not supported.

     * @param flags  if AVFILTER_CMD_FLAG_FAST is set and the command would be

     *               time consuming then a filter should treat it like an unsupported command

     *

     * @returns >=0 on success otherwise an error code.

     *          AVERROR(ENOSYS) on unsupported commands

     */

    int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);

    /**

     * Filter initialization function, alternative to the init()

     * callback. Args contains the user-supplied parameters, opaque is

     * used for providing binary data.

     */

    int (*init_opaque)(AVFilterContext *ctx, void *opaque);

} AVFilter;

/**

 * Process multiple parts of the frame concurrently.

 */

#define AVFILTER_THREAD_SLICE (1 << 0)

typedef struct AVFilterInternal AVFilterInternal;

/** An instance of a filter */

struct AVFilterContext {

    const AVClass *av_class;        ///< needed for av_log() and filters common options

    const AVFilter *filter;         ///< the AVFilter of which this is an instance

    char *name;                     ///< name of this filter instance

    AVFilterPad   *input_pads;      ///< array of input pads

    AVFilterLink **inputs;          ///< array of pointers to input links

#if FF_API_FOO_COUNT

    attribute_deprecated unsigned input_count; ///< @deprecated use nb_inputs

#endif

    unsigned    nb_inputs;          ///< number of input pads

    AVFilterPad   *output_pads;     ///< array of output pads

    AVFilterLink **outputs;         ///< array of pointers to output links

#if FF_API_FOO_COUNT

    attribute_deprecated unsigned output_count; ///< @deprecated use nb_outputs

#endif

    unsigned    nb_outputs;         ///< number of output pads

    void *priv;                     ///< private data for use by the filter

    struct AVFilterGraph *graph;    ///< filtergraph this filter belongs to

    /**

     * Type of multithreading being allowed/used. A combination of

     * AVFILTER_THREAD_* flags.

     *

     * May be set by the caller before initializing the filter to forbid some

     * or all kinds of multithreading for this filter. The default is allowing

     * everything.

     *

     * When the filter is initialized, this field is combined using bit AND with

     * AVFilterGraph.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.

     *

     * After the filter is initialzed, libavfilter sets this field to the

     * threading type that is actually used (0 for no multithreading).

     */

    int thread_type;

    /**

     * An opaque struct for libavfilter internal use.

     */

    AVFilterInternal *internal;

    struct AVFilterCommand *command_queue;

    char *enable_str;               ///< enable expression string

    void *enable;                   ///< parsed expression (AVExpr*)

    double *var_values;             ///< variable values for the enable expression

    int is_disabled;                ///< the enabled state from the last expression evaluation

};

/**

 * A link between two filters. This contains pointers to the source and

 * destination filters between which this link exists, and the indexes of

 * the pads involved. In addition, this link also contains the parameters

 * which have been negotiated and agreed upon between the filter, such as

 * image dimensions, format, etc.

 */

struct AVFilterLink {

    AVFilterContext *src;       ///< source filter

    AVFilterPad *srcpad;        ///< output pad on the source filter

    AVFilterContext *dst;       ///< dest filter

    AVFilterPad *dstpad;        ///< input pad on the dest filter

    enum AVMediaType type;      ///< filter media type

    /* These parameters apply only to video */

    int w;                      ///< agreed upon image width

    int h;                      ///< agreed upon image height

    AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio

    /* These parameters apply only to audio */

    uint64_t channel_layout;    ///< channel layout of current buffer (see libavutil/channel_layout.h)

    int sample_rate;            ///< samples per second

    int format;                 ///< agreed upon media format

    /**

     * Define the time base used by the PTS of the frames/samples

     * which will pass through this link.

     * During the configuration stage, each filter is supposed to

     * change only the output timebase, while the timebase of the

     * input link is assumed to be an unchangeable property.

     */

    AVRational time_base;

    /*****************************************************************

     * All fields below this line are not part of the public API. They

     * may not be used outside of libavfilter and can be changed and

     * removed at will.

     * New public fields should be added right above.

     *****************************************************************

     */

    /**

     * Lists of formats and channel layouts supported by the input and output

     * filters respectively. These lists are used for negotiating the format

     * to actually be used, which will be loaded into the format and

     * channel_layout members, above, when chosen.

     *

     */

    AVFilterFormats *in_formats;

    AVFilterFormats *out_formats;

    /**

     * Lists of channel layouts and sample rates used for automatic

     * negotiation.

     */

    AVFilterFormats  *in_samplerates;

    AVFilterFormats *out_samplerates;

    struct AVFilterChannelLayouts  *in_channel_layouts;

    struct AVFilterChannelLayouts *out_channel_layouts;

    /**

     * Audio only, the destination filter sets this to a non-zero value to

     * request that buffers with the given number of samples should be sent to

     * it. AVFilterPad.needs_fifo must also be set on the corresponding input

     * pad.

     * Last buffer before EOF will be padded with silence.

     */

    int request_samples;

    /** stage of the initialization of the link properties (dimensions, etc) */

    enum {

        AVLINK_UNINIT = 0,      ///< not started

        AVLINK_STARTINIT,       ///< started, but incomplete

        AVLINK_INIT             ///< complete

    } init_state;

    struct AVFilterPool *pool;

    /**

     * Graph the filter belongs to.

     */

    struct AVFilterGraph *graph;

    /**

     * Current timestamp of the link, as defined by the most recent

     * frame(s), in AV_TIME_BASE units.

     */

    int64_t current_pts;

    /**

     * Index in the age array.

     */

    int age_index;

    /**

     * Frame rate of the stream on the link, or 1/0 if unknown;

     * if left to 0/0, will be automatically be copied from the first input

     * of the source filter if it exists.

     *

     * Sources should set it to the best estimation of the real frame rate.

     * Filters should update it if necessary depending on their function.

     * Sinks can use it to set a default output frame rate.

     * It is similar to the r_frame_rate field in AVStream.

     */

    AVRational frame_rate;

    /**

     * Buffer partially filled with samples to achieve a fixed/minimum size.

     */

    AVFrame *partial_buf;

    /**

     * Size of the partial buffer to allocate.

     * Must be between min_samples and max_samples.

     */

    int partial_buf_size;

    /**

     * Minimum number of samples to filter at once. If filter_frame() is

     * called with fewer samples, it will accumulate them in partial_buf.

     * This field and the related ones must not be changed after filtering

     * has started.

     * If 0, all related fields are ignored.

     */

    int min_samples;

    /**

     * Maximum number of samples to filter at once. If filter_frame() is

     * called with more samples, it will split them.

     */

    int max_samples;

    /**

     * The buffer reference currently being received across the link by the

     * destination filter. This is used internally by the filter system to

     * allow automatic copying of buffers which do not have sufficient

     * permissions for the destination. This should not be accessed directly

     * by the filters.

     */

    AVFilterBufferRef *cur_buf_copy;

    /**

     * True if the link is closed.

     * If set, all attemps of start_frame, filter_frame or request_frame

     * will fail with AVERROR_EOF, and if necessary the reference will be

     * destroyed.

     * If request_frame returns AVERROR_EOF, this flag is set on the

     * corresponding link.

     * It can be set also be set by either the source or the destination

     * filter.

     */

    int closed;

    /**

     * Number of channels.

     */

    int channels;

    /**

     * True if a frame is being requested on the link.

     * Used internally by the framework.

     */

    unsigned frame_requested;

    /**

     * Link processing flags.

     */

    unsigned flags;

    /**

     * Number of past frames sent through the link.

     */

    int64_t frame_count;

};

/**

 * Link two filters together.

 *

 * @param src    the source filter

 * @param srcpad index of the output pad on the source filter

 * @param dst    the destination filter

 * @param dstpad index of the input pad on the destination filter

 * @return       zero on success

 */

int avfilter_link(AVFilterContext *src, unsigned srcpad,

                  AVFilterContext *dst, unsigned dstpad);

/**

 * Free the link in *link, and set its pointer to NULL.

 */

void avfilter_link_free(AVFilterLink **link);

/**

 * Get the number of channels of a link.

 */

int avfilter_link_get_channels(AVFilterLink *link);

/**

 * Set the closed field of a link.

 */

void avfilter_link_set_closed(AVFilterLink *link, int closed);

/**

 * Negotiate the media format, dimensions, etc of all inputs to a filter.

 *

 * @param filter the filter to negotiate the properties for its inputs

 * @return       zero on successful negotiation

 */

int avfilter_config_links(AVFilterContext *filter);

#if FF_API_AVFILTERBUFFER

/**

 * Create a buffer reference wrapped around an already allocated image

 * buffer.

 *

 * @param data pointers to the planes of the image to reference

 * @param linesize linesizes for the planes of the image to reference

 * @param perms the required access permissions

 * @param w the width of the image specified by the data and linesize arrays

 * @param h the height of the image specified by the data and linesize arrays

 * @param format the pixel format of the image specified by the data and linesize arrays

 */

attribute_deprecated

AVFilterBufferRef *

avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,

                                          int w, int h, enum AVPixelFormat format);

/**

 * Create an audio buffer reference wrapped around an already

 * allocated samples buffer.

 *

 * See avfilter_get_audio_buffer_ref_from_arrays_channels() for a version

 * that can handle unknown channel layouts.

 *

 * @param data           pointers to the samples plane buffers

 * @param linesize       linesize for the samples plane buffers

 * @param perms          the required access permissions

 * @param nb_samples     number of samples per channel

 * @param sample_fmt     the format of each sample in the buffer to allocate

 * @param channel_layout the channel layout of the buffer

 */

attribute_deprecated

AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,

                                                             int linesize,

                                                             int perms,

                                                             int nb_samples,

                                                             enum AVSampleFormat sample_fmt,

                                                             uint64_t channel_layout);

/**

 * Create an audio buffer reference wrapped around an already

 * allocated samples buffer.

 *

 * @param data           pointers to the samples plane buffers

 * @param linesize       linesize for the samples plane buffers

 * @param perms          the required access permissions

 * @param nb_samples     number of samples per channel

 * @param sample_fmt     the format of each sample in the buffer to allocate

 * @param channels       the number of channels of the buffer

 * @param channel_layout the channel layout of the buffer,

 *                       must be either 0 or consistent with channels

 */

attribute_deprecated

AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays_channels(uint8_t **data,

                                                                      int linesize,

                                                                      int perms,

                                                                      int nb_samples,

                                                                      enum AVSampleFormat sample_fmt,

                                                                      int channels,

                                                                      uint64_t channel_layout);

#endif

#define AVFILTER_CMD_FLAG_ONE   1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically

#define AVFILTER_CMD_FLAG_FAST  2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)

/**

 * Make the filter instance process a command.

 * It is recommended to use avfilter_graph_send_command().

 */

int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);

/** Initialize the filter system. Register all builtin filters. */

void avfilter_register_all(void);

#if FF_API_OLD_FILTER_REGISTER

/** Uninitialize the filter system. Unregister all filters. */

attribute_deprecated

void avfilter_uninit(void);

#endif

/**

 * Register a filter. This is only needed if you plan to use

 * avfilter_get_by_name later to lookup the AVFilter structure by name. A

 * filter can still by instantiated with avfilter_graph_alloc_filter even if it

 * is not registered.

 *

 * @param filter the filter to register

 * @return 0 if the registration was successful, a negative value

 * otherwise

 */

int avfilter_register(AVFilter *filter);

/**

 * Get a filter definition matching the given name.

 *

 * @param name the filter name to find

 * @return     the filter definition, if any matching one is registered.

 *             NULL if none found.

 */

AVFilter *avfilter_get_by_name(const char *name);

/**

 * Iterate over all registered filters.

 * @return If prev is non-NULL, next registered filter after prev or NULL if

 * prev is the last filter. If prev is NULL, return the first registered filter.

 */

const AVFilter *avfilter_next(const AVFilter *prev);

#if FF_API_OLD_FILTER_REGISTER

/**

 * If filter is NULL, returns a pointer to the first registered filter pointer,

 * if filter is non-NULL, returns the next pointer after filter.

 * If the returned pointer points to NULL, the last registered filter

 * was already reached.

 * @deprecated use avfilter_next()

 */

attribute_deprecated

AVFilter **av_filter_next(AVFilter **filter);

#endif

#if FF_API_AVFILTER_OPEN

/**

 * Create a filter instance.

 *

 * @param filter_ctx put here a pointer to the created filter context

 * on success, NULL on failure

 * @param filter    the filter to create an instance of

 * @param inst_name Name to give to the new instance. Can be NULL for none.

 * @return >= 0 in case of success, a negative error code otherwise

 * @deprecated use avfilter_graph_alloc_filter() instead

 */

attribute_deprecated

int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);

#endif

#if FF_API_AVFILTER_INIT_FILTER

/**

 * Initialize a filter.

 *

 * @param filter the filter to initialize

 * @param args   A string of parameters to use when initializing the filter.

 *               The format and meaning of this string varies by filter.

 * @param opaque Any extra non-string data needed by the filter. The meaning

 *               of this parameter varies by filter.

 * @return       zero on success

 */

attribute_deprecated

int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);

#endif

/**

 * Initialize a filter with the supplied parameters.

 *

 * @param ctx  uninitialized filter context to initialize

 * @param args Options to initialize the filter with. This must be a

 *             ':'-separated list of options in the 'key=value' form.

 *             May be NULL if the options have been set directly using the

 *             AVOptions API or there are no options that need to be set.

 * @return 0 on success, a negative AVERROR on failure

 */

int avfilter_init_str(AVFilterContext *ctx, const char *args);

/**

 * Initialize a filter with the supplied dictionary of options.

 *

 * @param ctx     uninitialized filter context to initialize

 * @param options An AVDictionary filled with options for this filter. On

 *                return this parameter will be destroyed and replaced with

 *                a dict containing options that were not found. This dictionary

 *                must be freed by the caller.

 *                May be NULL, then this function is equivalent to

 *                avfilter_init_str() with the second parameter set to NULL.

 * @return 0 on success, a negative AVERROR on failure

 *

 * @note This function and avfilter_init_str() do essentially the same thing,

 * the difference is in manner in which the options are passed. It is up to the

 * calling code to choose whichever is more preferable. The two functions also

 * behave differently when some of the provided options are not declared as

 * supported by the filter. In such a case, avfilter_init_str() will fail, but

 * this function will leave those extra options in the options AVDictionary and

 * continue as usual.

 */

int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);

/**

 * Free a filter context. This will also remove the filter from its

 * filtergraph's list of filters.

 *

 * @param filter the filter to free

 */

void avfilter_free(AVFilterContext *filter);

/**

 * Insert a filter in the middle of an existing link.

 *

 * @param link the link into which the filter should be inserted

 * @param filt the filter to be inserted

 * @param filt_srcpad_idx the input pad on the filter to connect

 * @param filt_dstpad_idx the output pad on the filter to connect

 * @return     zero on success

 */

int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,

                           unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);

#if FF_API_AVFILTERBUFFER

/**

 * Copy the frame properties of src to dst, without copying the actual

 * image data.

 *

 * @return 0 on success, a negative number on error.

 */

attribute_deprecated

int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);

/**

 * Copy the frame properties and data pointers of src to dst, without copying

 * the actual data.

 *

 * @return 0 on success, a negative number on error.

 */

attribute_deprecated

int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);

#endif

/**

 * @return AVClass for AVFilterContext.

 *

 * @see av_opt_find().

 */

const AVClass *avfilter_get_class(void);

typedef struct AVFilterGraphInternal AVFilterGraphInternal;

/**