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ffmpeg/libavfilter/avfilter.h
Anton Khirnov ca860d8d07 lavfi: clarify the behaviour of avfilter_graph_create_filter() 
Mention explicitly that no options can be set manually when using this
function.
2024-09-28 17:04:33 +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;
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
/**
* 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;
/**
* Ready status of the filter.
* A non-0 value means that the filter needs activating;
* a higher value suggests a more urgent activation.
*/
unsigned ready;
/**
* 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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