/* * filter layer * Copyright (c) 2007 Bobby Bingham * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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 "libavutil/attributes.h" #include "libavutil/avutil.h" #include "libavutil/buffer.h" #include "libavutil/frame.h" #include "libavutil/log.h" #include "libavutil/samplefmt.h" #include "libavutil/pixfmt.h" #include "libavutil/rational.h" #include #include "libavfilter/version.h" /** * Return the LIBAVFILTER_VERSION_INT constant. */ unsigned avfilter_version(void); /** * Return the libavfilter build-time configuration. */ const char *avfilter_configuration(void); /** * Return the libavfilter license. */ const char *avfilter_license(void); typedef struct AVFilterContext AVFilterContext; typedef struct AVFilterLink AVFilterLink; typedef struct AVFilterPad AVFilterPad; typedef struct AVFilterFormats AVFilterFormats; /** * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g. * AVFilter.inputs/outputs). */ int avfilter_pad_count(const AVFilterPad *pads); /** * Get the name of an AVFilterPad. * * @param pads an array of AVFilterPads * @param pad_idx index of the pad in the array it; is the caller's * responsibility to ensure the index is valid * * @return name of the pad_idx'th pad in pads */ const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx); /** * Get the type of an AVFilterPad. * * @param pads an array of AVFilterPads * @param pad_idx index of the pad in the array; it is the caller's * responsibility to ensure the index is valid * * @return type of the pad_idx'th pad in pads */ enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx); /** * The number of the filter inputs is not determined just by AVFilter.inputs. * The filter might add additional inputs during initialization depending on the * options supplied to it. */ #define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0) /** * The number of the filter outputs is not determined just by AVFilter.outputs. * The filter might add additional outputs during initialization depending on * the options supplied to it. */ #define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1) /** * The filter supports multithreading by splitting frames into multiple parts * and processing them concurrently. */ #define AVFILTER_FLAG_SLICE_THREADS (1 << 2) /** * Filter definition. This defines the pads a filter contains, and all the * callback functions used to interact with the filter. */ typedef struct AVFilter { /** * Filter name. Must be non-NULL and unique among filters. */ const char *name; /** * A description of the filter. May be NULL. * * You should use the NULL_IF_CONFIG_SMALL() macro to define it. */ const char *description; /** * List of inputs, terminated by a zeroed element. * * NULL if there are no (static) inputs. Instances of filters with * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in * this list. */ const AVFilterPad *inputs; /** * List of outputs, terminated by a zeroed element. * * NULL if there are no (static) outputs. Instances of filters with * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in * this list. */ const AVFilterPad *outputs; /** * A class for the private data, used to declare filter private AVOptions. * This field is NULL for filters that do not declare any options. * * If this field is non-NULL, the first member of the filter private data * must be a pointer to AVClass, which will be set by libavfilter generic * code to this class. */ const AVClass *priv_class; /** * A combination of AVFILTER_FLAG_* */ int flags; /***************************************************************** * All fields below this line are not part of the public API. They * may not be used outside of libavfilter and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ /** * Filter initialization function. * * This callback will be called only once during the filter lifetime, after * all the options have been set, but before links between filters are * established and format negotiation is done. * * Basic filter initialization should be done here. Filters with dynamic * inputs and/or outputs should create those inputs/outputs here based on * provided options. No more changes to this filter's inputs/outputs can be * done after this callback. * * This callback must not assume that the filter links exist or frame * parameters are known. * * @ref AVFilter.uninit "uninit" is guaranteed to be called even if * initialization fails, so this callback does not have to clean up on * failure. * * @return 0 on success, a negative AVERROR on failure */ int (*init)(AVFilterContext *ctx); /** * Should be set instead of @ref AVFilter.init "init" by the filters that * want to pass a dictionary of AVOptions to nested contexts that are * allocated during init. * * On return, the options dict should be freed and replaced with one that * contains all the options which could not be processed by this filter (or * with NULL if all the options were processed). * * Otherwise the semantics is the same as for @ref AVFilter.init "init". */ int (*init_dict)(AVFilterContext *ctx, AVDictionary **options); /** * Filter uninitialization function. * * Called only once right before the filter is freed. Should deallocate any * memory held by the filter, release any buffer references, etc. It does * not need to deallocate the AVFilterContext.priv memory itself. * * This callback may be called even if @ref AVFilter.init "init" was not * called or failed, so it must be prepared to handle such a situation. */ void (*uninit)(AVFilterContext *ctx); /** * Query formats supported by the filter on its inputs and outputs. * * This callback is called after the filter is initialized (so the inputs * and outputs are fixed), shortly before the format negotiation. This * callback may be called more than once. * * This callback must set AVFilterLink.out_formats on every input link and * AVFilterLink.in_formats on every output link to a list of pixel/sample * formats that the filter supports on that link. For audio links, this * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" / * @ref AVFilterLink.out_samplerates "out_samplerates" and * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" / * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously. * * This callback may be NULL for filters with one input, in which case * libavfilter assumes that it supports all input formats and preserves * them on output. * * @return zero on success, a negative value corresponding to an * AVERROR code otherwise */ int (*query_formats)(AVFilterContext *); int priv_size; ///< size of private data to allocate for the filter /** * Used by the filter registration system. Must not be touched by any other * code. */ struct AVFilter *next; } AVFilter; /** * Process multiple parts of the frame concurrently. */ #define AVFILTER_THREAD_SLICE (1 << 0) typedef struct AVFilterInternal AVFilterInternal; /** An instance of a filter */ struct AVFilterContext { const AVClass *av_class; ///< needed for av_log() 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 initialzed, libavfilter sets this field to the * threading type that is actually used (0 for no multithreading). */ int thread_type; /** * An opaque struct for libavfilter internal use. */ AVFilterInternal *internal; /** * 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. */ AVBufferRef *hw_device_ctx; }; /** * A link between two filters. This contains pointers to the source and * destination filters between which this link exists, and the indexes of * the pads involved. In addition, this link also contains the parameters * which have been negotiated and agreed upon between the filter, such as * image dimensions, format, etc. */ struct AVFilterLink { AVFilterContext *src; ///< source filter AVFilterPad *srcpad; ///< output pad on the source filter AVFilterContext *dst; ///< dest filter AVFilterPad *dstpad; ///< input pad on the dest filter enum AVMediaType type; ///< filter media type /* These parameters apply only to video */ int w; ///< agreed upon image width int h; ///< agreed upon image height AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio /* These two parameters apply only to audio */ uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h) int sample_rate; ///< samples per second int format; ///< agreed upon media format /** * Define the time base used by the PTS of the frames/samples * which will pass through this link. * During the configuration stage, each filter is supposed to * change only the output timebase, while the timebase of the * input link is assumed to be an unchangeable property. */ AVRational time_base; /***************************************************************** * All fields below this line are not part of the public API. They * may not be used outside of libavfilter and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ /** * Lists of formats supported by the input and output filters respectively. * These lists are used for negotiating the format to actually be used, * which will be loaded into the format member, above, when chosen. */ AVFilterFormats *in_formats; AVFilterFormats *out_formats; /** * Lists of channel layouts and sample rates used for automatic * negotiation. */ AVFilterFormats *in_samplerates; AVFilterFormats *out_samplerates; struct AVFilterChannelLayouts *in_channel_layouts; struct AVFilterChannelLayouts *out_channel_layouts; /** * Audio only, the destination filter sets this to a non-zero value to * request that buffers with the given number of samples should be sent to * it. AVFilterPad.needs_fifo must also be set on the corresponding input * pad. * Last buffer before EOF will be padded with silence. */ int request_samples; /** stage of the initialization of the link properties (dimensions, etc) */ enum { AVLINK_UNINIT = 0, ///< not started AVLINK_STARTINIT, ///< started, but incomplete AVLINK_INIT ///< complete } init_state; /** * Frame rate of the stream on the link, or 1/0 if unknown or variable; * if left to 0/0, will be automatically copied from the first input * of the source filter if it exists. * * Sources should set it to the real constant frame rate. * If the source frame rate is unknown or variable, set this to 1/0. * Filters should update it if necessary depending on their function. * Sinks can use it to set a default output frame rate. */ AVRational frame_rate; /** * For hwaccel pixel formats, this should be a reference to the * AVHWFramesContext describing the frames. */ AVBufferRef *hw_frames_ctx; }; /** * 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); /** * Negotiate the media format, dimensions, etc of all inputs to a filter. * * @param filter the filter to negotiate the properties for its inputs * @return zero on successful negotiation */ int avfilter_config_links(AVFilterContext *filter); /** Initialize the filter system. Register all builtin filters. */ void avfilter_register_all(void); #if FF_API_OLD_FILTER_REGISTER /** Uninitialize the filter system. Unregister all filters. */ attribute_deprecated void avfilter_uninit(void); #endif /** * Register a filter. This is only needed if you plan to use * avfilter_get_by_name later to lookup the AVFilter structure by name. A * filter can still by instantiated with avfilter_graph_alloc_filter even if it * is not registered. * * @param filter the filter to register * @return 0 if the registration was successful, a negative value * otherwise */ int avfilter_register(AVFilter *filter); /** * Get a filter definition matching the given name. * * @param name the filter name to find * @return the filter definition, if any matching one is registered. * NULL if none found. */ #if !FF_API_NOCONST_GET_NAME const #endif AVFilter *avfilter_get_by_name(const char *name); /** * Iterate over all registered filters. * @return If prev is non-NULL, next registered filter after prev or NULL if * prev is the last filter. If prev is NULL, return the first registered filter. */ const AVFilter *avfilter_next(const AVFilter *prev); #if FF_API_OLD_FILTER_REGISTER /** * If filter is NULL, returns a pointer to the first registered filter pointer, * if filter is non-NULL, returns the next pointer after filter. * If the returned pointer points to NULL, the last registered filter * was already reached. * @deprecated use avfilter_next() */ attribute_deprecated AVFilter **av_filter_next(AVFilter **filter); #endif #if FF_API_AVFILTER_OPEN /** * Create a filter instance. * * @param filter_ctx put here a pointer to the created filter context * on success, NULL on failure * @param filter the filter to create an instance of * @param inst_name Name to give to the new instance. Can be NULL for none. * @return >= 0 in case of success, a negative error code otherwise * @deprecated use avfilter_graph_alloc_filter() instead */ attribute_deprecated int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name); #endif #if FF_API_AVFILTER_INIT_FILTER /** * Initialize a filter. * * @param filter the filter to initialize * @param args A string of parameters to use when initializing the filter. * The format and meaning of this string varies by filter. * @param opaque Any extra non-string data needed by the filter. The meaning * of this parameter varies by filter. * @return zero on success */ attribute_deprecated int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque); #endif /** * Initialize a filter with the supplied parameters. * * @param ctx uninitialized filter context to initialize * @param args Options to initialize the filter with. This must be a * ':'-separated list of options in the 'key=value' form. * May be NULL if the options have been set directly using the * AVOptions API or there are no options that need to be set. * @return 0 on success, a negative AVERROR on failure */ int avfilter_init_str(AVFilterContext *ctx, const char *args); /** * Initialize a filter with the supplied dictionary of options. * * @param ctx uninitialized filter context to initialize * @param options An AVDictionary filled with options for this filter. On * return this parameter will be destroyed and replaced with * a dict containing options that were not found. This dictionary * must be freed by the caller. * May be NULL, then this function is equivalent to * avfilter_init_str() with the second parameter set to NULL. * @return 0 on success, a negative AVERROR on failure * * @note This function and avfilter_init_str() do essentially the same thing, * the difference is in manner in which the options are passed. It is up to the * calling code to choose whichever is more preferable. The two functions also * behave differently when some of the provided options are not declared as * supported by the filter. In such a case, avfilter_init_str() will fail, but * this function will leave those extra options in the options AVDictionary and * continue as usual. */ int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options); /** * Free a filter context. This will also remove the filter from its * filtergraph's list of filters. * * @param filter the filter to free */ void avfilter_free(AVFilterContext *filter); /** * Insert a filter in the middle of an existing link. * * @param link the link into which the filter should be inserted * @param filt the filter to be inserted * @param filt_srcpad_idx the input pad on the filter to connect * @param filt_dstpad_idx the output pad on the filter to connect * @return zero on success */ int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt, unsigned filt_srcpad_idx, unsigned filt_dstpad_idx); /** * @return AVClass for AVFilterContext. * * @see av_opt_find(). */ const AVClass *avfilter_get_class(void); typedef struct AVFilterGraphInternal AVFilterGraphInternal; /** * 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 char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample 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 object for libavfilter internal use. */ AVFilterGraphInternal *internal; /** * 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; } 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 or failure. */ AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph, const AVFilter *filter, const char *name); /** * Get a filter instance with name name from graph. * * @return the pointer to the found filter instance or NULL if it * cannot be found. */ AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name); #if FF_API_AVFILTER_OPEN /** * Add an existing filter instance to a filter graph. * * @param graphctx the filter graph * @param filter the filter to be added * * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a * filter graph */ attribute_deprecated int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter); #endif /** * Create and add a filter instance into an existing graph. * The filter instance is created from the filter filt and inited * with the parameters args and opaque. * * In case of success put in *filt_ctx the pointer to the created * filter instance, otherwise set *filt_ctx to NULL. * * @param name the instance name to give to the created filter instance * @param graph_ctx the filter graph * @return a negative AVERROR error code in case of failure, a non * negative value otherwise */ int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt, const char *name, const char *args, void *opaque, AVFilterGraph *graph_ctx); /** * Check validity and configure all the links and formats in the graph. * * @param graphctx the filter graph * @param log_ctx context used for logging * @return 0 in case of success, a negative AVERROR code otherwise */ int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx); /** * Free a graph, destroy its links, and set *graph to NULL. * If *graph is NULL, do nothing. */ void avfilter_graph_free(AVFilterGraph **graph); /** * A linked-list of the inputs/outputs of the filter chain. * * This is mainly useful for avfilter_graph_parse() / 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. * * @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. * * @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 the difference between avfilter_graph_parse2() and * avfilter_graph_parse() is that in avfilter_graph_parse(), the caller provides * the lists of inputs and outputs, which therefore must be known before calling * the function. On the other hand, avfilter_graph_parse2() \em returns the * inputs and outputs that are left unlinked after parsing the graph and the * caller then deals with them. Another difference is that in * avfilter_graph_parse(), 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. * avfilter_graph_parse2() takes the opposite approach -- it 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); /** * @} */ #endif /* AVFILTER_AVFILTER_H */