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FFmpeg/libavfilter/avfilter.h
Anton Khirnov 6647e57dcb lavfi/avfilter: document AVFilterContext.is_disabled as private 
Ideally there should be three parts to the filter context - public,
private to the filter, and private to generic code, but only the first
and the last of these exist currently. Until the second is implemented,
this is better than nothing.
2024-10-07 10:53:13 +02:00

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/*
* 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 <stddef.h>
#include "libavutil/attributes.h"
#include "libavutil/avutil.h"
#include "libavutil/buffer.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_major.h"
#ifndef HAVE_AV_CONFIG_H
/* When included as part of the ffmpeg build, only include the major version
* to avoid unnecessary rebuilds. When included externally, keep including
* the full version information. */
#include "libavfilter/version.h"
#endif
/**
* 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;
typedef struct AVFilterChannelLayouts AVFilterChannelLayouts;
/**
* 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);
/**
* Lists of formats / etc. supported by an end of a link.
*
* This structure is directly part of AVFilterLink, in two copies:
* one for the source filter, one for the destination filter.
* These lists are used for negotiating the format to actually be used,
* which will be loaded into the format and channel_layout members of
* AVFilterLink, when chosen.
*/
typedef struct AVFilterFormatsConfig {
/**
* List of supported formats (pixel or sample).
*/
AVFilterFormats *formats;
/**
* Lists of supported sample rates, only for audio.
*/
AVFilterFormats *samplerates;
/**
* Lists of supported channel layouts, only for audio.
*/
AVFilterChannelLayouts *channel_layouts;
/**
* Lists of supported YUV color metadata, only for YUV video.
*/
AVFilterFormats *color_spaces; ///< AVColorSpace
AVFilterFormats *color_ranges; ///< AVColorRange
} AVFilterFormatsConfig;
/**
* 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)
/**
* The filter is a "metadata" filter - it does not modify the frame data in any
* way. It may only affect the metadata (i.e. those fields copied by
* av_frame_copy_props()).
*
* More precisely, this means:
* - video: the data of any frame output by the filter must be exactly equal to
* some frame that is received on one of its inputs. Furthermore, all frames
* produced on a given output must correspond to frames received on the same
* input and their order must be unchanged. Note that the filter may still
* drop or duplicate the frames.
* - audio: the data produced by the filter on any of its outputs (viewed e.g.
* as an array of interleaved samples) must be exactly equal to the data
* received by the filter on one of its inputs.
*/
#define AVFILTER_FLAG_METADATA_ONLY (1 << 3)
/**
* The filter can create hardware frames using AVFilterContext.hw_device_ctx.
*/
#define AVFILTER_FLAG_HWDEVICE (1 << 4)
/**
* 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 static inputs.
*
* 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 static outputs.
*
* 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.
*****************************************************************
*/
/**
* The number of entries in the list of inputs.
*/
uint8_t nb_inputs;
/**
* The number of entries in the list of outputs.
*/
uint8_t nb_outputs;
/**
* This field determines the state of the formats union.
* It is an enum FilterFormatsState value.
*/
uint8_t formats_state;
/**
* Filter pre-initialization function
*
* This callback will be called immediately after the filter context is
* allocated, to allow allocating and initing sub-objects.
*
* If this callback is not NULL, the uninit callback will be called on
* allocation failure.
*
* @return 0 on success,
* AVERROR code on failure (but the code will be
* dropped and treated as ENOMEM by the calling code)
*/
int (*preinit)(AVFilterContext *ctx);
/**
* 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);
/**
* 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);
/**
* The state of the following union is determined by formats_state.
* See the documentation of enum FilterFormatsState in internal.h.
*/
union {
/**
* 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's
* @ref AVFilterFormatsConfig.formats "outcfg.formats"
* on every input link and
* @ref AVFilterFormatsConfig.formats "incfg.formats"
* on every output link to a list of pixel/sample formats that the filter
* supports on that link.
* For video links, this filter may also set
* @ref AVFilterFormatsConfig.color_spaces "incfg.color_spaces"
* /
* @ref AVFilterFormatsConfig.color_spaces "outcfg.color_spaces"
* and @ref AVFilterFormatsConfig.color_ranges "incfg.color_ranges"
* /
* @ref AVFilterFormatsConfig.color_ranges "outcfg.color_ranges"
* analogously.
* For audio links, this filter must also set
* @ref AVFilterFormatsConfig.samplerates "incfg.samplerates"
* /
* @ref AVFilterFormatsConfig.samplerates "outcfg.samplerates"
* and @ref AVFilterFormatsConfig.channel_layouts "incfg.channel_layouts"
* /
* @ref AVFilterFormatsConfig.channel_layouts "outcfg.channel_layouts"
* analogously.
*
* This callback must never be NULL if the union is in this state.
*
* @return zero on success, a negative value corresponding to an
* AVERROR code otherwise
*/
int (*query_func)(AVFilterContext *);
/**
* Same as query_func(), except this function writes the results into
* provided arrays.
*
* @param cfg_in array of input format configurations with as many
* members as the filters has inputs (NULL when there are
* no inputs);
* @param cfg_out array of output format configurations with as many
* members as the filters has outputs (NULL when there
* are no outputs);
*/
int (*query_func2)(const AVFilterContext *,
struct AVFilterFormatsConfig **cfg_in,
struct AVFilterFormatsConfig **cfg_out);
/**
* A pointer to an array of admissible pixel formats delimited
* by AV_PIX_FMT_NONE. The generic code will use this list
* to indicate that this filter supports each of these pixel formats,
* provided that all inputs and outputs use the same pixel format.
*
* In addition to that the generic code will mark all inputs
* and all outputs as supporting all color spaces and ranges, as
* long as all inputs and outputs use the same color space/range.
*
* This list must never be NULL if the union is in this state.
* The type of all inputs and outputs of filters using this must
* be AVMEDIA_TYPE_VIDEO.
*/
const enum AVPixelFormat *pixels_list;
/**
* Analogous to pixels, but delimited by AV_SAMPLE_FMT_NONE
* and restricted to filters that only have AVMEDIA_TYPE_AUDIO
* inputs and outputs.
*
* In addition to that the generic code will mark all inputs
* and all outputs as supporting all sample rates and every
* channel count and channel layout, as long as all inputs
* and outputs use the same sample rate and channel count/layout.
*/
const enum AVSampleFormat *samples_list;
/**
* Equivalent to { pix_fmt, AV_PIX_FMT_NONE } as pixels_list.
*/
enum AVPixelFormat pix_fmt;
/**
* Equivalent to { sample_fmt, AV_SAMPLE_FMT_NONE } as samples_list.
*/
enum AVSampleFormat sample_fmt;
} formats;
int priv_size; ///< size of private data to allocate for the filter
int flags_internal; ///< Additional flags for avfilter internal use only.
/**
* 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 activation function.
*
* Called when any processing is needed from the filter, instead of any
* filter_frame and request_frame on pads.
*
* The function must examine inlinks and outlinks and perform a single
* step of processing. If there is nothing to do, the function must do
* nothing and not return an error. If more steps are or may be
* possible, it must use ff_filter_set_ready() to schedule another
* activation.
*/
int (*activate)(AVFilterContext *ctx);
} AVFilter;
/**
* Get the number of elements in an AVFilter's inputs or outputs array.
*/
unsigned avfilter_filter_pad_count(const AVFilter *filter, int is_output);
/**
* Process multiple parts of the frame concurrently.
*/
#define AVFILTER_THREAD_SLICE (1 << 0)
/** 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
unsigned nb_inputs; ///< number of input pads
AVFilterPad *output_pads; ///< array of output pads
AVFilterLink **outputs; ///< array of pointers to output links
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 initialized, libavfilter sets this field to the
* threading type that is actually used (0 for no multithreading).
*/
int thread_type;
/**
* Max number of threads allowed in this filter instance.
* If <= 0, its value is ignored.
* Overrides global number of threads set per filter graph.
*/
int nb_threads;
#if FF_API_CONTEXT_PUBLIC
/**
* @deprecated unused
*/
attribute_deprecated
struct AVFilterCommand *command_queue;
#endif
char *enable_str; ///< enable expression string
#if FF_API_CONTEXT_PUBLIC
/**
* @deprecated unused
*/
attribute_deprecated
void *enable;
/**
* @deprecated unused
*/
double *var_values;
#endif
/**
* MUST NOT be accessed from outside avfilter.
*
* the enabled state from the last expression evaluation
*/
int is_disabled;
/**
* For filters which will create hardware frames, sets the device the
* filter should create them in. All other filters will ignore this field:
* in particular, a filter which consumes or processes hardware frames will
* instead use the hw_frames_ctx field in AVFilterLink to carry the
* hardware context information.
*
* May be set by the caller on filters flagged with AVFILTER_FLAG_HWDEVICE
* before initializing the filter with avfilter_init_str() or
* avfilter_init_dict().
*/
AVBufferRef *hw_device_ctx;
#if FF_API_CONTEXT_PUBLIC
/**
* @deprecated this field should never have been accessed by callers
*/
attribute_deprecated
unsigned ready;
#endif
/**
* Sets the number of extra hardware frames which the filter will
* allocate on its output links for use in following filters or by
* the caller.
*
* Some hardware filters require all frames that they will use for
* output to be defined in advance before filtering starts. For such
* filters, any hardware frame pools used for output must therefore be
* of fixed size. The extra frames set here are on top of any number
* that the filter needs internally in order to operate normally.
*
* This field must be set before the graph containing this filter is
* configured.
*/
int extra_hw_frames;
};
/**
* 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.
*
* Applications must not normally access the link structure directly.
* Use the buffersrc and buffersink API instead.
* In the future, access to the header may be reserved for filters
* implementation.
*/
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
int format; ///< agreed upon media format
/* 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
/**
* For non-YUV links, these are respectively set to fallback values (as
* appropriate for that colorspace).
*
* Note: This includes grayscale formats, as these are currently treated
* as forced full range always.
*/
enum AVColorSpace colorspace; ///< agreed upon YUV color space
enum AVColorRange color_range; ///< agreed upon YUV color range
/* These parameters apply only to audio */
int sample_rate; ///< samples per second
AVChannelLayout ch_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
/**
* 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 supported formats / etc. supported by the input filter.
*/
AVFilterFormatsConfig incfg;
/**
* Lists of supported formats / etc. supported by the output filter.
*/
AVFilterFormatsConfig outcfg;
};
/**
* 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);
#if FF_API_LINK_PUBLIC
/**
* @deprecated this function should never be called by users
*/
attribute_deprecated
void avfilter_link_free(AVFilterLink **link);
/**
* @deprecated this function should never be called by users
*/
attribute_deprecated
int avfilter_config_links(AVFilterContext *filter);
#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);
/**
* Iterate over all registered filters.
*
* @param opaque a pointer where libavfilter will store the iteration state. Must
* point to NULL to start the iteration.
*
* @return the next registered filter or NULL when the iteration is
* finished
*/
const AVFilter *av_filter_iterate(void **opaque);
/**
* 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.
*/
const AVFilter *avfilter_get_by_name(const char *name);
/**
* 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);
/**
* @return AVClass for AVFilterContext.
*
* @see av_opt_find().
*/
const AVClass *avfilter_get_class(void);
/**
* A function pointer passed to the @ref AVFilterGraph.execute callback to be
* executed multiple times, possibly in parallel.
*
* @param ctx the filter context the job belongs to
* @param arg an opaque parameter passed through from @ref
* AVFilterGraph.execute
* @param jobnr the index of the job being executed
* @param nb_jobs the total number of jobs
*
* @return 0 on success, a negative AVERROR on error
*/
typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
/**
* A function executing multiple jobs, possibly in parallel.
*
* @param ctx the filter context to which the jobs belong
* @param func the function to be called multiple times
* @param arg the argument to be passed to func
* @param ret a nb_jobs-sized array to be filled with return values from each
* invocation of func
* @param nb_jobs the number of jobs to execute
*
* @return 0 on success, a negative AVERROR on error
*/
typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
void *arg, int *ret, int nb_jobs);
typedef struct AVFilterGraph {
const AVClass *av_class;
AVFilterContext **filters;
unsigned nb_filters;
char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
/**
* Type of multithreading allowed for filters in this graph. A combination
* of AVFILTER_THREAD_* flags.
*
* May be set by the caller at any point, the setting will apply to all
* filters initialized after that. The default is allowing everything.
*
* When a filter in this graph is initialized, this field is combined using
* bit AND with AVFilterContext.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.
*/
int thread_type;
/**
* Maximum number of threads used by filters in this graph. May be set by
* the caller before adding any filters to the filtergraph. Zero (the
* default) means that the number of threads is determined automatically.
*/
int nb_threads;
/**
* Opaque user data. May be set by the caller to an arbitrary value, e.g. to
* be used from callbacks like @ref AVFilterGraph.execute.
* Libavfilter will not touch this field in any way.
*/
void *opaque;
/**
* This callback may be set by the caller immediately after allocating the
* graph and before adding any filters to it, to provide a custom
* multithreading implementation.
*
* If set, filters with slice threading capability will call this callback
* to execute multiple jobs in parallel.
*
* If this field is left unset, libavfilter will use its internal
* implementation, which may or may not be multithreaded depending on the
* platform and build options.
*/
avfilter_execute_func *execute;
char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
} AVFilterGraph;
/**
* Allocate a filter graph.
*
* @return the allocated filter graph on success or NULL.
*/
AVFilterGraph *avfilter_graph_alloc(void);
/**
* Create a new filter instance in a filter graph.
*
* @param graph graph in which the new filter will be used
* @param filter the filter to create an instance of
* @param name Name to give to the new instance (will be copied to
* AVFilterContext.name). This may be used by the caller to identify
* different filters, libavfilter itself assigns no semantics to
* this parameter. May be NULL.
*
* @return the context of the newly created filter instance (note that it is
* also retrievable directly through AVFilterGraph.filters or with
* avfilter_graph_get_filter()) on success or NULL on failure.
*/
AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
const AVFilter *filter,
const char *name);
/**
* Get a filter instance identified by instance name from graph.
*
* @param graph filter graph to search through.
* @param name filter instance name (should be unique in the graph).
* @return the pointer to the found filter instance or NULL if it
* cannot be found.
*/
AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, const char *name);
/**
* A convenience wrapper that allocates and initializes a filter in a single
* step. The filter instance is created from the filter filt and inited with the
* parameter args. opaque is currently ignored.
*
* 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
*
* @warning Since the filter is initialized after this function successfully
* returns, you MUST NOT set any further options on it. If you need to
* do that, call ::avfilter_graph_alloc_filter(), followed by setting
* the options, followed by ::avfilter_init_dict() instead of this
* function.
*/
int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const 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 aresample 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.
*
* @note The caller must provide the lists of inputs and outputs,
* which therefore must be known before calling the function.
*
* @note The inputs parameter describes inputs of the already existing
* 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.
*
* @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);
/**
* Add a graph described by a string to a graph.
*
* In the graph filters description, if the input label of the first
* filter is not specified, "in" is assumed; if the output label of
* the last filter is not specified, "out" is assumed.
*
* @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_ptr(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 This function returns the inputs and outputs that are left
* unlinked after parsing the graph and the caller then deals with
* them.
* @note This function 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);
/**
* Parameters of a filter's input or output pad.
*
* Created as a child of AVFilterParams by avfilter_graph_segment_parse().
* Freed in avfilter_graph_segment_free().
*/
typedef struct AVFilterPadParams {
/**
* An av_malloc()'ed string containing the pad label.
*
* May be av_free()'d and set to NULL by the caller, in which case this pad
* will be treated as unlabeled for linking.
* May also be replaced by another av_malloc()'ed string.
*/
char *label;
} AVFilterPadParams;
/**
* Parameters describing a filter to be created in a filtergraph.
*
* Created as a child of AVFilterGraphSegment by avfilter_graph_segment_parse().
* Freed in avfilter_graph_segment_free().
*/
typedef struct AVFilterParams {
/**
* The filter context.
*
* Created by avfilter_graph_segment_create_filters() based on
* AVFilterParams.filter_name and instance_name.
*
* Callers may also create the filter context manually, then they should
* av_free() filter_name and set it to NULL. Such AVFilterParams instances
* are then skipped by avfilter_graph_segment_create_filters().
*/
AVFilterContext *filter;
/**
* Name of the AVFilter to be used.
*
* An av_malloc()'ed string, set by avfilter_graph_segment_parse(). Will be
* passed to avfilter_get_by_name() by
* avfilter_graph_segment_create_filters().
*
* Callers may av_free() this string and replace it with another one or
* NULL. If the caller creates the filter instance manually, this string
* MUST be set to NULL.
*
* When both AVFilterParams.filter an AVFilterParams.filter_name are NULL,
* this AVFilterParams instance is skipped by avfilter_graph_segment_*()
* functions.
*/
char *filter_name;
/**
* Name to be used for this filter instance.
*
* An av_malloc()'ed string, may be set by avfilter_graph_segment_parse() or
* left NULL. The caller may av_free() this string and replace with another
* one or NULL.
*
* Will be used by avfilter_graph_segment_create_filters() - passed as the
* third argument to avfilter_graph_alloc_filter(), then freed and set to
* NULL.
*/
char *instance_name;
/**
* Options to be apllied to the filter.
*
* Filled by avfilter_graph_segment_parse(). Afterwards may be freely
* modified by the caller.
*
* Will be applied to the filter by avfilter_graph_segment_apply_opts()
* with an equivalent of av_opt_set_dict2(filter, &opts, AV_OPT_SEARCH_CHILDREN),
* i.e. any unapplied options will be left in this dictionary.
*/
AVDictionary *opts;
AVFilterPadParams **inputs;
unsigned nb_inputs;
AVFilterPadParams **outputs;
unsigned nb_outputs;
} AVFilterParams;
/**
* A filterchain is a list of filter specifications.
*
* Created as a child of AVFilterGraphSegment by avfilter_graph_segment_parse().
* Freed in avfilter_graph_segment_free().
*/
typedef struct AVFilterChain {
AVFilterParams **filters;
size_t nb_filters;
} AVFilterChain;
/**
* A parsed representation of a filtergraph segment.
*
* A filtergraph segment is conceptually a list of filterchains, with some
* supplementary information (e.g. format conversion flags).
*
* Created by avfilter_graph_segment_parse(). Must be freed with
* avfilter_graph_segment_free().
*/
typedef struct AVFilterGraphSegment {
/**
* The filtergraph this segment is associated with.
* Set by avfilter_graph_segment_parse().
*/
AVFilterGraph *graph;
/**
* A list of filter chain contained in this segment.
* Set in avfilter_graph_segment_parse().
*/
AVFilterChain **chains;
size_t nb_chains;
/**
* A string containing a colon-separated list of key=value options applied
* to all scale filters in this segment.
*
* May be set by avfilter_graph_segment_parse().
* The caller may free this string with av_free() and replace it with a
* different av_malloc()'ed string.
*/
char *scale_sws_opts;
} AVFilterGraphSegment;
/**
* Parse a textual filtergraph description into an intermediate form.
*
* This intermediate representation is intended to be modified by the caller as
* described in the documentation of AVFilterGraphSegment and its children, and
* then applied to the graph either manually or with other
* avfilter_graph_segment_*() functions. See the documentation for
* avfilter_graph_segment_apply() for the canonical way to apply
* AVFilterGraphSegment.
*
* @param graph Filter graph the parsed segment is associated with. Will only be
* used for logging and similar auxiliary purposes. The graph will
* not be actually modified by this function - the parsing results
* are instead stored in seg for further processing.
* @param graph_str a string describing the filtergraph segment
* @param flags reserved for future use, caller must set to 0 for now
* @param seg A pointer to the newly-created AVFilterGraphSegment is written
* here on success. The graph segment is owned by the caller and must
* be freed with avfilter_graph_segment_free() before graph itself is
* freed.
*
* @retval "non-negative number" success
* @retval "negative error code" failure
*/
int avfilter_graph_segment_parse(AVFilterGraph *graph, const char *graph_str,
int flags, AVFilterGraphSegment **seg);
/**
* Create filters specified in a graph segment.
*
* Walk through the creation-pending AVFilterParams in the segment and create
* new filter instances for them.
* Creation-pending params are those where AVFilterParams.filter_name is
* non-NULL (and hence AVFilterParams.filter is NULL). All other AVFilterParams
* instances are ignored.
*
* For any filter created by this function, the corresponding
* AVFilterParams.filter is set to the newly-created filter context,
* AVFilterParams.filter_name and AVFilterParams.instance_name are freed and set
* to NULL.
*
* @param seg the filtergraph segment to process
* @param flags reserved for future use, caller must set to 0 for now
*
* @retval "non-negative number" Success, all creation-pending filters were
* successfully created
* @retval AVERROR_FILTER_NOT_FOUND some filter's name did not correspond to a
* known filter
* @retval "another negative error code" other failures
*
* @note Calling this function multiple times is safe, as it is idempotent.
*/
int avfilter_graph_segment_create_filters(AVFilterGraphSegment *seg, int flags);
/**
* Apply parsed options to filter instances in a graph segment.
*
* Walk through all filter instances in the graph segment that have option
* dictionaries associated with them and apply those options with
* av_opt_set_dict2(..., AV_OPT_SEARCH_CHILDREN). AVFilterParams.opts is
* replaced by the dictionary output by av_opt_set_dict2(), which should be
* empty (NULL) if all options were successfully applied.
*
* If any options could not be found, this function will continue processing all
* other filters and finally return AVERROR_OPTION_NOT_FOUND (unless another
* error happens). The calling program may then deal with unapplied options as
* it wishes.
*
* Any creation-pending filters (see avfilter_graph_segment_create_filters())
* present in the segment will cause this function to fail. AVFilterParams with
* no associated filter context are simply skipped.
*
* @param seg the filtergraph segment to process
* @param flags reserved for future use, caller must set to 0 for now
*
* @retval "non-negative number" Success, all options were successfully applied.
* @retval AVERROR_OPTION_NOT_FOUND some options were not found in a filter
* @retval "another negative error code" other failures
*
* @note Calling this function multiple times is safe, as it is idempotent.
*/
int avfilter_graph_segment_apply_opts(AVFilterGraphSegment *seg, int flags);
/**
* Initialize all filter instances in a graph segment.
*
* Walk through all filter instances in the graph segment and call
* avfilter_init_dict(..., NULL) on those that have not been initialized yet.
*
* Any creation-pending filters (see avfilter_graph_segment_create_filters())
* present in the segment will cause this function to fail. AVFilterParams with
* no associated filter context or whose filter context is already initialized,
* are simply skipped.
*
* @param seg the filtergraph segment to process
* @param flags reserved for future use, caller must set to 0 for now
*
* @retval "non-negative number" Success, all filter instances were successfully
* initialized
* @retval "negative error code" failure
*
* @note Calling this function multiple times is safe, as it is idempotent.
*/
int avfilter_graph_segment_init(AVFilterGraphSegment *seg, int flags);
/**
* Link filters in a graph segment.
*
* Walk through all filter instances in the graph segment and try to link all
* unlinked input and output pads. Any creation-pending filters (see
* avfilter_graph_segment_create_filters()) present in the segment will cause
* this function to fail. Disabled filters and already linked pads are skipped.
*
* Every filter output pad that has a corresponding AVFilterPadParams with a
* non-NULL label is
* - linked to the input with the matching label, if one exists;
* - exported in the outputs linked list otherwise, with the label preserved.
* Unlabeled outputs are
* - linked to the first unlinked unlabeled input in the next non-disabled
* filter in the chain, if one exists
* - exported in the ouputs linked list otherwise, with NULL label
*
* Similarly, unlinked input pads are exported in the inputs linked list.
*
* @param seg the filtergraph segment to process
* @param flags reserved for future use, caller must set to 0 for now
* @param[out] inputs a linked list of all free (unlinked) inputs of the
* filters in this graph segment 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
* filters in this graph segment will be returned here. It
* is to be freed by the caller using avfilter_inout_free().
*
* @retval "non-negative number" success
* @retval "negative error code" failure
*
* @note Calling this function multiple times is safe, as it is idempotent.
*/
int avfilter_graph_segment_link(AVFilterGraphSegment *seg, int flags,
AVFilterInOut **inputs,
AVFilterInOut **outputs);
/**
* Apply all filter/link descriptions from a graph segment to the associated filtergraph.
*
* This functions is currently equivalent to calling the following in sequence:
* - avfilter_graph_segment_create_filters();
* - avfilter_graph_segment_apply_opts();
* - avfilter_graph_segment_init();
* - avfilter_graph_segment_link();
* failing if any of them fails. This list may be extended in the future.
*
* Since the above functions are idempotent, the caller may call some of them
* manually, then do some custom processing on the filtergraph, then call this
* function to do the rest.
*
* @param seg the filtergraph segment to process
* @param flags reserved for future use, caller must set to 0 for now
* @param[out] inputs passed to avfilter_graph_segment_link()
* @param[out] outputs passed to avfilter_graph_segment_link()
*
* @retval "non-negative number" success
* @retval "negative error code" failure
*
* @note Calling this function multiple times is safe, as it is idempotent.
*/
int avfilter_graph_segment_apply(AVFilterGraphSegment *seg, int flags,
AVFilterInOut **inputs,
AVFilterInOut **outputs);
/**
* Free the provided AVFilterGraphSegment and everything associated with it.
*
* @param seg double pointer to the AVFilterGraphSegment to be freed. NULL will
* be written to this pointer on exit from this function.
*
* @note
* The filter contexts (AVFilterParams.filter) are owned by AVFilterGraph rather
* than AVFilterGraphSegment, so they are not freed.
*/
void avfilter_graph_segment_free(AVFilterGraphSegment **seg);
/**
* 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 send, 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 alphanumeric 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_AVFILTER_H */
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