/* * filter layer * Copyright (c) 2007 Bobby Bingham * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVFILTER_AVFILTER_H #define AVFILTER_AVFILTER_H /** * @file * @ingroup lavfi * Main libavfilter public API header */ /** * @defgroup lavfi libavfilter * Graph-based frame editing library. * * @{ */ #include #include "libavutil/attributes.h" #include "libavutil/avutil.h" #include "libavutil/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.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) /** * Some filters support a generic "enable" expression option that can be used * to enable or disable a filter in the timeline. Filters supporting this * option have this flag set. When the enable expression is false, the default * no-op filter_frame() function is called in place of the filter_frame() * callback defined on each input pad, thus the frame is passed unchanged to * the next filters. */ #define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16) /** * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will * have its filter_frame() callback(s) called as usual even when the enable * expression is false. The filter will disable filtering within the * filter_frame() callback(s) itself, for example executing code depending on * the AVFilterContext->is_disabled value. */ #define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17) /** * Handy mask to test whether the filter supports or no the timeline feature * (internally or generically). */ #define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL) /** * Filter definition. This defines the pads a filter contains, and all the * callback functions used to interact with the filter. */ typedef struct AVFilter { /** * Filter name. Must be non-NULL and unique among filters. */ const char *name; /** * A description of the filter. May be NULL. * * You should use the NULL_IF_CONFIG_SMALL() macro to define it. */ const char *description; /** * List of inputs, terminated by a zeroed element. * * NULL if there are no (static) inputs. Instances of filters with * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in * this list. */ const AVFilterPad *inputs; /** * List of outputs, terminated by a zeroed element. * * NULL if there are no (static) outputs. Instances of filters with * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in * this list. */ const AVFilterPad *outputs; /** * A class for the private data, used to declare filter private AVOptions. * This field is NULL for filters that do not declare any options. * * If this field is non-NULL, the first member of the filter private data * must be a pointer to AVClass, which will be set by libavfilter generic * code to this class. */ const AVClass *priv_class; /** * A combination of AVFILTER_FLAG_* */ int flags; /***************************************************************** * All fields below this line are not part of the public API. They * may not be used outside of libavfilter and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ /** * Filter 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); /** * 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 int flags_internal; ///< Additional flags for avfilter internal use only. /** * Used by the filter registration system. Must not be touched by any other * code. */ struct AVFilter *next; /** * Make the filter instance process a command. * * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only * @param arg the argument for the command * @param res a buffer with size res_size where the filter(s) can return a response. This must not change when the command is not supported. * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be * time consuming then a filter should treat it like an unsupported command * * @returns >=0 on success otherwise an error code. * AVERROR(ENOSYS) on unsupported commands */ int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags); /** * Filter initialization function, alternative to the init() * callback. Args contains the user-supplied parameters, opaque is * used for providing binary data. */ int (*init_opaque)(AVFilterContext *ctx, void *opaque); /** * 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; /** * Process multiple parts of the frame concurrently. */ #define AVFILTER_THREAD_SLICE (1 << 0) typedef struct AVFilterInternal AVFilterInternal; /** An instance of a filter */ struct AVFilterContext { const AVClass *av_class; ///< needed for av_log() and filters common options const AVFilter *filter; ///< the AVFilter of which this is an instance char *name; ///< name of this filter instance AVFilterPad *input_pads; ///< array of input pads AVFilterLink **inputs; ///< array of pointers to input links 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; /** * An opaque struct for libavfilter internal use. */ AVFilterInternal *internal; struct AVFilterCommand *command_queue; char *enable_str; ///< enable expression string void *enable; ///< parsed expression (AVExpr*) double *var_values; ///< variable values for the enable expression int is_disabled; ///< the enabled state from the last expression evaluation /** * 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; /** * 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; /** * 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 /* These parameters apply only to video */ int w; ///< agreed upon image width int h; ///< agreed upon image height AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio /* These parameters apply only to audio */ uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h) int sample_rate; ///< samples per second int format; ///< agreed upon media format /** * Define the time base used by the PTS of the frames/samples * which will pass through this link. * During the configuration stage, each filter is supposed to * change only the output timebase, while the timebase of the * input link is assumed to be an unchangeable property. */ AVRational time_base; /***************************************************************** * All fields below this line are not part of the public API. They * may not be used outside of libavfilter and can be changed and * removed at will. * New public fields should be added right above. ***************************************************************** */ /** * Lists of formats and channel layouts supported by the input and output * filters respectively. These lists are used for negotiating the format * to actually be used, which will be loaded into the format and * channel_layout members, above, when chosen. * */ AVFilterFormats *in_formats; AVFilterFormats *out_formats; /** * Lists of channel layouts and sample rates used for automatic * negotiation. */ AVFilterFormats *in_samplerates; AVFilterFormats *out_samplerates; struct AVFilterChannelLayouts *in_channel_layouts; struct AVFilterChannelLayouts *out_channel_layouts; /** * Audio only, the destination filter sets this to a non-zero value to * request that buffers with the given number of samples should be sent to * it. AVFilterPad.needs_fifo must also be set on the corresponding input * pad. * Last buffer before EOF will be padded with silence. */ int request_samples; /** stage of the initialization of the link properties (dimensions, etc) */ enum { AVLINK_UNINIT = 0, ///< not started AVLINK_STARTINIT, ///< started, but incomplete AVLINK_INIT ///< complete } init_state; /** * Graph the filter belongs to. */ struct AVFilterGraph *graph; /** * Current timestamp of the link, as defined by the most recent * frame(s), in link time_base units. */ int64_t current_pts; /** * Current timestamp of the link, as defined by the most recent * frame(s), in AV_TIME_BASE units. */ int64_t current_pts_us; /** * Index in the age array. */ int age_index; /** * 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 best estimation of the real 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. * It is similar to the r_frame_rate field in AVStream. */ AVRational frame_rate; /** * Buffer partially filled with samples to achieve a fixed/minimum size. */ AVFrame *partial_buf; /** * Size of the partial buffer to allocate. * Must be between min_samples and max_samples. */ int partial_buf_size; /** * Minimum number of samples to filter at once. If filter_frame() is * called with fewer samples, it will accumulate them in partial_buf. * This field and the related ones must not be changed after filtering * has started. * If 0, all related fields are ignored. */ int min_samples; /** * Maximum number of samples to filter at once. If filter_frame() is * called with more samples, it will split them. */ int max_samples; /** * Number of channels. */ int channels; /** * Link processing flags. */ unsigned flags; /** * Number of past frames sent through the link. */ int64_t frame_count_in, frame_count_out; /** * A pointer to a FFFramePool struct. */ void *frame_pool; /** * True if a frame is currently wanted on the output of this filter. * Set when ff_request_frame() is called by the output, * cleared when a frame is filtered. */ int frame_wanted_out; /** * For hwaccel pixel formats, this should be a reference to the * AVHWFramesContext describing the frames. */ AVBufferRef *hw_frames_ctx; #ifndef FF_INTERNAL_FIELDS /** * Internal structure members. * The fields below this limit are internal for libavfilter's use * and must in no way be accessed by applications. */ char reserved[0xF000]; #else /* FF_INTERNAL_FIELDS */ /** * Queue of frames waiting to be filtered. */ FFFrameQueue fifo; /** * If set, the source filter can not generate a frame as is. * The goal is to avoid repeatedly calling the request_frame() method on * the same link. */ int frame_blocked_in; /** * Link input status. * If not zero, all attempts of filter_frame will fail with the * corresponding code. */ int status_in; /** * Timestamp of the input status change. */ int64_t status_in_pts; /** * Link output status. * If not zero, all attempts of request_frame will fail with the * corresponding code. */ int status_out; #endif /* FF_INTERNAL_FIELDS */ }; /** * Link two filters together. * * @param src the source filter * @param srcpad index of the output pad on the source filter * @param dst the destination filter * @param dstpad index of the input pad on the destination filter * @return zero on success */ int avfilter_link(AVFilterContext *src, unsigned srcpad, AVFilterContext *dst, unsigned dstpad); /** * Free the link in *link, and set its pointer to NULL. */ void avfilter_link_free(AVFilterLink **link); #if FF_API_FILTER_GET_SET /** * Get the number of channels of a link. * @deprecated Use av_buffersink_get_channels() */ attribute_deprecated int avfilter_link_get_channels(AVFilterLink *link); #endif /** * Set the closed field of a link. * @deprecated applications are not supposed to mess with links, they should * close the sinks. */ attribute_deprecated void avfilter_link_set_closed(AVFilterLink *link, int closed); /** * Negotiate the media format, dimensions, etc of all inputs to a filter. * * @param filter the filter to negotiate the properties for its inputs * @return zero on successful negotiation */ int avfilter_config_links(AVFilterContext *filter); #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); #if FF_API_NEXT /** Initialize the filter system. Register all builtin filters. */ attribute_deprecated void avfilter_register_all(void); /** * 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 */ attribute_deprecated int avfilter_register(AVFilter *filter); /** * 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. */ attribute_deprecated const AVFilter *avfilter_next(const AVFilter *prev); #endif /** * 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); 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 #if FF_API_LAVR_OPTS attribute_deprecated char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters #endif /** * 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; char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions /** * Private fields * * The following fields are for internal use only. * Their type, offset, number and semantic can change without notice. */ AVFilterLink **sink_links; int sink_links_count; unsigned disable_auto_convert; } 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); /** * 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); /** * 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); /** * 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 */