/* * 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 #include "libavutil/avutil.h" #include "libavutil/log.h" #include "libavutil/samplefmt.h" #include "libavutil/pixfmt.h" #include "libavutil/rational.h" #define LIBAVFILTER_VERSION_MAJOR 2 #define LIBAVFILTER_VERSION_MINOR 27 #define LIBAVFILTER_VERSION_MICRO 5 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ LIBAVFILTER_VERSION_MINOR, \ LIBAVFILTER_VERSION_MICRO) #define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \ LIBAVFILTER_VERSION_MINOR, \ LIBAVFILTER_VERSION_MICRO) #define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT #include /** * 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; /** * A reference-counted buffer data type used by the filter system. Filters * should not store pointers to this structure directly, but instead use the * AVFilterBufferRef structure below. */ typedef struct AVFilterBuffer { uint8_t *data[8]; ///< buffer data for each plane/channel int linesize[8]; ///< number of bytes per line unsigned refcount; ///< number of references to this buffer /** private data to be used by a custom free function */ void *priv; /** * A pointer to the function to deallocate this buffer if the default * function is not sufficient. This could, for example, add the memory * back into a memory pool to be reused later without the overhead of * reallocating it from scratch. */ void (*free)(struct AVFilterBuffer *buf); int format; ///< media format int w, h; ///< width and height of the allocated buffer } AVFilterBuffer; #define AV_PERM_READ 0x01 ///< can read from the buffer #define AV_PERM_WRITE 0x02 ///< can write to the buffer #define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time #define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time #define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes /** * Audio specific properties in a reference to an AVFilterBuffer. Since * AVFilterBufferRef is common to different media formats, audio specific * per reference properties must be separated out. */ typedef struct AVFilterBufferRefAudioProps { int64_t channel_layout; ///< channel layout of audio buffer int nb_samples; ///< number of audio samples per channel uint32_t sample_rate; ///< audio buffer sample rate int planar; ///< audio buffer - planar or packed } AVFilterBufferRefAudioProps; /** * Video specific properties in a reference to an AVFilterBuffer. Since * AVFilterBufferRef is common to different media formats, video specific * per reference properties must be separated out. */ typedef struct AVFilterBufferRefVideoProps { int w; ///< image width int h; ///< image height AVRational sample_aspect_ratio; ///< sample aspect ratio int interlaced; ///< is frame interlaced int top_field_first; ///< field order enum AVPictureType pict_type; ///< picture type of the frame int key_frame; ///< 1 -> keyframe, 0-> not } AVFilterBufferRefVideoProps; /** * A reference to an AVFilterBuffer. Since filters can manipulate the origin of * a buffer to, for example, crop image without any memcpy, the buffer origin * and dimensions are per-reference properties. Linesize is also useful for * image flipping, frame to field filters, etc, and so is also per-reference. * * TODO: add anything necessary for frame reordering */ typedef struct AVFilterBufferRef { AVFilterBuffer *buf; ///< the buffer that this is a reference to uint8_t *data[8]; ///< picture/audio data for each plane int linesize[8]; ///< number of bytes per line int format; ///< media format /** * presentation timestamp. The time unit may change during * filtering, as it is specified in the link and the filter code * may need to rescale the PTS accordingly. */ int64_t pts; int64_t pos; ///< byte position in stream, -1 if unknown int perms; ///< permissions, see the AV_PERM_* flags enum AVMediaType type; ///< media type of buffer data AVFilterBufferRefVideoProps *video; ///< video buffer specific properties AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties } AVFilterBufferRef; /** * Copy properties of src to dst, without copying the actual data */ static inline void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src) { // copy common properties dst->pts = src->pts; dst->pos = src->pos; switch (src->type) { case AVMEDIA_TYPE_VIDEO: *dst->video = *src->video; break; case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break; default: break; } } /** * Add a new reference to a buffer. * * @param ref an existing reference to the buffer * @param pmask a bitmask containing the allowable permissions in the new * reference * @return a new reference to the buffer with the same properties as the * old, excluding any permissions denied by pmask */ AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask); /** * Remove a reference to a buffer. If this is the last reference to the * buffer, the buffer itself is also automatically freed. * * @param ref reference to the buffer, may be NULL */ void avfilter_unref_buffer(AVFilterBufferRef *ref); /** * A list of supported formats for one end of a filter link. This is used * during the format negotiation process to try to pick the best format to * use to minimize the number of necessary conversions. Each filter gives a * list of the formats supported by each input and output pad. The list * given for each pad need not be distinct - they may be references to the * same list of formats, as is often the case when a filter supports multiple * formats, but will always output the same format as it is given in input. * * In this way, a list of possible input formats and a list of possible * output formats are associated with each link. When a set of formats is * negotiated over a link, the input and output lists are merged to form a * new list containing only the common elements of each list. In the case * that there were no common elements, a format conversion is necessary. * Otherwise, the lists are merged, and all other links which reference * either of the format lists involved in the merge are also affected. * * For example, consider the filter chain: * filter (a) --> (b) filter (b) --> (c) filter * * where the letters in parenthesis indicate a list of formats supported on * the input or output of the link. Suppose the lists are as follows: * (a) = {A, B} * (b) = {A, B, C} * (c) = {B, C} * * First, the first link's lists are merged, yielding: * filter (a) --> (a) filter (a) --> (c) filter * * Notice that format list (b) now refers to the same list as filter list (a). * Next, the lists for the second link are merged, yielding: * filter (a) --> (a) filter (a) --> (a) filter * * where (a) = {B}. * * Unfortunately, when the format lists at the two ends of a link are merged, * we must ensure that all links which reference either pre-merge format list * get updated as well. Therefore, we have the format list structure store a * pointer to each of the pointers to itself. */ typedef struct AVFilterFormats { unsigned format_count; ///< number of formats int64_t *formats; ///< list of media formats unsigned refcount; ///< number of references to this list struct AVFilterFormats ***refs; ///< references to this list } AVFilterFormats; /** * Create a list of supported formats. This is intended for use in * AVFilter->query_formats(). * * @param fmts list of media formats, terminated by -1. If NULL an * empty list is created. * @return the format list, with no existing references */ AVFilterFormats *avfilter_make_format_list(const int *fmts); AVFilterFormats *avfilter_make_format64_list(const int64_t *fmts); /** * Add fmt to the list of media formats contained in *avff. * If *avff is NULL the function allocates the filter formats struct * and puts its pointer in *avff. * * @return a non negative value in case of success, or a negative * value corresponding to an AVERROR code in case of error */ int avfilter_add_format(AVFilterFormats **avff, int64_t fmt); /** * Return a list of all formats supported by FFmpeg for the given media type. */ AVFilterFormats *avfilter_all_formats(enum AVMediaType type); /** * Return a list of all channel layouts supported by FFmpeg. */ AVFilterFormats *avfilter_all_channel_layouts(void); /** * Return a list of all audio packing formats. */ AVFilterFormats *avfilter_all_packing_formats(void); /** * Return a format list which contains the intersection of the formats of * a and b. Also, all the references of a, all the references of b, and * a and b themselves will be deallocated. * * If a and b do not share any common formats, neither is modified, and NULL * is returned. */ AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b); /** * Add *ref as a new reference to formats. * That is the pointers will point like in the ascii art below: * ________ * |formats |<--------. * | ____ | ____|___________________ * | |refs| | | __|_ * | |* * | | | | | | AVFilterLink * | |* *--------->|*ref| * | |____| | | |____| * |________| |________________________ */ void avfilter_formats_ref(AVFilterFormats *formats, AVFilterFormats **ref); /** * If *ref is non-NULL, remove *ref as a reference to the format list * it currently points to, deallocates that list if this was the last * reference, and sets *ref to NULL. * * Before After * ________ ________ NULL * |formats |<--------. |formats | ^ * | ____ | ____|________________ | ____ | ____|________________ * | |refs| | | __|_ | |refs| | | __|_ * | |* * | | | | | | AVFilterLink | |* * | | | | | | AVFilterLink * | |* *--------->|*ref| | |* | | | |*ref| * | |____| | | |____| | |____| | | |____| * |________| |_____________________ |________| |_____________________ */ void avfilter_formats_unref(AVFilterFormats **ref); /** * * Before After * ________ ________ * |formats |<---------. |formats |<---------. * | ____ | ___|___ | ____ | ___|___ * | |refs| | | | | | |refs| | | | | NULL * | |* *--------->|*oldref| | |* *--------->|*newref| ^ * | |* * | | |_______| | |* * | | |_______| ___|___ * | |____| | | |____| | | | | * |________| |________| |*oldref| * |_______| */ void avfilter_formats_changeref(AVFilterFormats **oldref, AVFilterFormats **newref); /** * A filter pad used for either input or output. */ struct AVFilterPad { /** * Pad name. The name is unique among inputs and among outputs, but an * input may have the same name as an output. This may be NULL if this * pad has no need to ever be referenced by name. */ const char *name; /** * AVFilterPad type. Only video supported now, hopefully someone will * add audio in the future. */ enum AVMediaType type; /** * Minimum required permissions on incoming buffers. Any buffer with * insufficient permissions will be automatically copied by the filter * system to a new buffer which provides the needed access permissions. * * Input pads only. */ int min_perms; /** * Permissions which are not accepted on incoming buffers. Any buffer * which has any of these permissions set will be automatically copied * by the filter system to a new buffer which does not have those * permissions. This can be used to easily disallow buffers with * AV_PERM_REUSE. * * Input pads only. */ int rej_perms; /** * Callback called before passing the first slice of a new frame. If * NULL, the filter layer will default to storing a reference to the * picture inside the link structure. * * Input video pads only. */ void (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref); /** * Callback function to get a video buffer. If NULL, the filter system will * use avfilter_default_get_video_buffer(). * * Input video pads only. */ AVFilterBufferRef *(*get_video_buffer)(AVFilterLink *link, int perms, int w, int h); /** * Callback function to get an audio buffer. If NULL, the filter system will * use avfilter_default_get_audio_buffer(). * * Input audio pads only. */ AVFilterBufferRef *(*get_audio_buffer)(AVFilterLink *link, int perms, enum AVSampleFormat sample_fmt, int nb_samples, int64_t channel_layout, int planar); /** * Callback called after the slices of a frame are completely sent. If * NULL, the filter layer will default to releasing the reference stored * in the link structure during start_frame(). * * Input video pads only. */ void (*end_frame)(AVFilterLink *link); /** * Slice drawing callback. This is where a filter receives video data * and should do its processing. * * Input video pads only. */ void (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir); /** * Samples filtering callback. This is where a filter receives audio data * and should do its processing. * * Input audio pads only. */ void (*filter_samples)(AVFilterLink *link, AVFilterBufferRef *samplesref); /** * Frame poll callback. This returns the number of immediately available * samples. It should return a positive value if the next request_frame() * is guaranteed to return one frame (with no delay). * * Defaults to just calling the source poll_frame() method. * * Output video pads only. */ int (*poll_frame)(AVFilterLink *link); /** * Frame request callback. A call to this should result in at least one * frame being output over the given link. This should return zero on * success, and another value on error. * * Output video pads only. */ int (*request_frame)(AVFilterLink *link); /** * Link configuration callback. * * For output pads, this should set the link properties such as * width/height. This should NOT set the format property - that is * negotiated between filters by the filter system using the * query_formats() callback before this function is called. * * For input pads, this should check the properties of the link, and update * the filter's internal state as necessary. * * For both input and output filters, this should return zero on success, * and another value on error. */ int (*config_props)(AVFilterLink *link); }; /** default handler for start_frame() for video inputs */ void avfilter_default_start_frame(AVFilterLink *link, AVFilterBufferRef *picref); /** default handler for draw_slice() for video inputs */ void avfilter_default_draw_slice(AVFilterLink *link, int y, int h, int slice_dir); /** default handler for end_frame() for video inputs */ void avfilter_default_end_frame(AVFilterLink *link); /** default handler for filter_samples() for audio inputs */ void avfilter_default_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref); /** default handler for get_video_buffer() for video inputs */ AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms, int w, int h); /** default handler for get_audio_buffer() for audio inputs */ AVFilterBufferRef *avfilter_default_get_audio_buffer(AVFilterLink *link, int perms, enum AVSampleFormat sample_fmt, int nb_samples, int64_t channel_layout, int planar); /** * Helpers for query_formats() which set all links to the same list of * formats/layouts. If there are no links hooked to this filter, the list * of formats is freed. */ void avfilter_set_common_pixel_formats(AVFilterContext *ctx, AVFilterFormats *formats); void avfilter_set_common_sample_formats(AVFilterContext *ctx, AVFilterFormats *formats); void avfilter_set_common_channel_layouts(AVFilterContext *ctx, AVFilterFormats *formats); void avfilter_set_common_packing_formats(AVFilterContext *ctx, AVFilterFormats *formats); /** Default handler for query_formats() */ int avfilter_default_query_formats(AVFilterContext *ctx); /** start_frame() handler for filters which simply pass video along */ void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref); /** draw_slice() handler for filters which simply pass video along */ void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir); /** end_frame() handler for filters which simply pass video along */ void avfilter_null_end_frame(AVFilterLink *link); /** filter_samples() handler for filters which simply pass audio along */ void avfilter_null_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref); /** get_video_buffer() handler for filters which simply pass video along */ AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link, int perms, int w, int h); /** get_audio_buffer() handler for filters which simply pass audio along */ AVFilterBufferRef *avfilter_null_get_audio_buffer(AVFilterLink *link, int perms, enum AVSampleFormat sample_fmt, int size, int64_t channel_layout, int planar); /** * Filter definition. This defines the pads a filter contains, and all the * callback functions used to interact with the filter. */ typedef struct AVFilter { const char *name; ///< filter name int priv_size; ///< size of private data to allocate for the filter /** * Filter initialization function. Args contains the user-supplied * parameters. FIXME: maybe an AVOption-based system would be better? * opaque is data provided by the code requesting creation of the filter, * and is used to pass data to the filter. */ int (*init)(AVFilterContext *ctx, const char *args, void *opaque); /** * Filter uninitialization function. Should deallocate any memory held * by the filter, release any buffer references, etc. This does not need * to deallocate the AVFilterContext->priv memory itself. */ void (*uninit)(AVFilterContext *ctx); /** * Queries formats/layouts supported by the filter and its pads, and sets * the in_formats/in_chlayouts for links connected to its output pads, * and out_formats/out_chlayouts for links connected to its input pads. * * @return zero on success, a negative value corresponding to an * AVERROR code otherwise */ int (*query_formats)(AVFilterContext *); const AVFilterPad *inputs; ///< NULL terminated list of inputs. NULL if none const AVFilterPad *outputs; ///< NULL terminated list of outputs. NULL if none /** * A description for the filter. You should use the * NULL_IF_CONFIG_SMALL() macro to define it. */ const char *description; } AVFilter; /** An instance of a filter */ struct AVFilterContext { const AVClass *av_class; ///< needed for av_log() AVFilter *filter; ///< the AVFilter of which this is an instance char *name; ///< name of this filter instance unsigned input_count; ///< number of input pads AVFilterPad *input_pads; ///< array of input pads AVFilterLink **inputs; ///< array of pointers to input links unsigned output_count; ///< number of output pads AVFilterPad *output_pads; ///< array of output pads AVFilterLink **outputs; ///< array of pointers to output links void *priv; ///< private data for use by the filter }; enum AVFilterPacking { AVFILTER_PACKED = 0, AVFILTER_PLANAR, }; /** * 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 /** 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; 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 */ int64_t channel_layout; ///< channel layout of current buffer (see libavutil/audioconvert.h) int64_t sample_rate; ///< samples per second int planar; ///< agreed upon packing mode of audio buffers. true if planar. int format; ///< agreed upon media format /** * 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; AVFilterFormats *in_chlayouts; AVFilterFormats *out_chlayouts; AVFilterFormats *in_packing; AVFilterFormats *out_packing; /** * The buffer reference currently being sent across the link by the source * filter. This is used internally by the filter system to allow * automatic copying of buffers which do not have sufficient permissions * for the destination. This should not be accessed directly by the * filters. */ AVFilterBufferRef *src_buf; AVFilterBufferRef *cur_buf; AVFilterBufferRef *out_buf; /** * 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; struct AVFilterPool *pool; }; /** * 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); /** * 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); /** * Request a picture buffer with a specific set of permissions. * * @param link the output link to the filter from which the buffer will * be requested * @param perms the required access permissions * @param w the minimum width of the buffer to allocate * @param h the minimum height of the buffer to allocate * @return A reference to the buffer. This must be unreferenced with * avfilter_unref_buffer when you are finished with it. */ AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms, int w, int h); /** * Create a buffer reference wrapped around an already allocated image * buffer. * * @param data pointers to the planes of the image to reference * @param linesize linesizes for the planes of the image to reference * @param perms the required access permissions * @param w the width of the image specified by the data and linesize arrays * @param h the height of the image specified by the data and linesize arrays * @param format the pixel format of the image specified by the data and linesize arrays */ AVFilterBufferRef * avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms, int w, int h, enum PixelFormat format); /** * Request an audio samples buffer with a specific set of permissions. * * @param link the output link to the filter from which the buffer will * be requested * @param perms the required access permissions * @param sample_fmt the format of each sample in the buffer to allocate * @param nb_samples the number of samples per channel * @param channel_layout the number and type of channels per sample in the buffer to allocate * @param planar audio data layout - planar or packed * @return A reference to the samples. This must be unreferenced with * avfilter_unref_buffer when you are finished with it. */ AVFilterBufferRef *avfilter_get_audio_buffer(AVFilterLink *link, int perms, enum AVSampleFormat sample_fmt, int nb_samples, int64_t channel_layout, int planar); /** * Create an audio buffer reference wrapped around an already * allocated samples buffer. * * @param data pointers to the samples plane buffers * @param linesize linesize for the samples plane buffers * @param perms the required access permissions * @param nb_samples number of samples per channel * @param sample_fmt the format of each sample in the buffer to allocate * @param channel_layout the channel layout of the buffer * @param planar audio data layout - planar or packed */ AVFilterBufferRef * avfilter_get_audio_buffer_ref_from_arrays(uint8_t *data[8], int linesize[8], int perms, int nb_samples, enum AVSampleFormat sample_fmt, int64_t channel_layout, int planar); /** * Request an input frame from the filter at the other end of the link. * * @param link the input link * @return zero on success */ int avfilter_request_frame(AVFilterLink *link); /** * Poll a frame from the filter chain. * * @param link the input link * @return the number of immediately available frames, a negative * number in case of error */ int avfilter_poll_frame(AVFilterLink *link); /** * Notifie the next filter of the start of a frame. * * @param link the output link the frame will be sent over * @param picref A reference to the frame about to be sent. The data for this * frame need only be valid once draw_slice() is called for that * portion. The receiving filter will free this reference when * it no longer needs it. */ void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref); /** * Notifie the next filter that the current frame has finished. * * @param link the output link the frame was sent over */ void avfilter_end_frame(AVFilterLink *link); /** * Send a slice to the next filter. * * Slices have to be provided in sequential order, either in * top-bottom or bottom-top order. If slices are provided in * non-sequential order the behavior of the function is undefined. * * @param link the output link over which the frame is being sent * @param y offset in pixels from the top of the image for this slice * @param h height of this slice in pixels * @param slice_dir the assumed direction for sending slices, * from the top slice to the bottom slice if the value is 1, * from the bottom slice to the top slice if the value is -1, * for other values the behavior of the function is undefined. */ void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir); /** * Send a buffer of audio samples to the next filter. * * @param link the output link over which the audio samples are being sent * @param samplesref a reference to the buffer of audio samples being sent. The * receiving filter will free this reference when it no longer * needs it or pass it on to the next filter. */ void avfilter_filter_samples(AVFilterLink *link, AVFilterBufferRef *samplesref); /** Initialize the filter system. Register all builtin filters. */ void avfilter_register_all(void); /** Uninitialize the filter system. Unregister all filters. */ void avfilter_uninit(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_open even if it is not * registered. * * @param filter the filter to register * @return 0 if the registration was succesfull, a negative value * otherwise */ int avfilter_register(AVFilter *filter); /** * Get a filter definition matching the given name. * * @param name the filter name to find * @return the filter definition, if any matching one is registered. * NULL if none found. */ AVFilter *avfilter_get_by_name(const char *name); /** * 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. */ AVFilter **av_filter_next(AVFilter **filter); /** * 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 */ int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name); /** * 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 */ int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque); /** * Free a filter context. * * @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); /** * Insert a new pad. * * @param idx Insertion point. Pad is inserted at the end if this point * is beyond the end of the list of pads. * @param count Pointer to the number of pads in the list * @param padidx_off Offset within an AVFilterLink structure to the element * to increment when inserting a new pad causes link * numbering to change * @param pads Pointer to the pointer to the beginning of the list of pads * @param links Pointer to the pointer to the beginning of the list of links * @param newpad The new pad to add. A copy is made when adding. */ void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off, AVFilterPad **pads, AVFilterLink ***links, AVFilterPad *newpad); /** Insert a new input pad for the filter. */ static inline void avfilter_insert_inpad(AVFilterContext *f, unsigned index, AVFilterPad *p) { avfilter_insert_pad(index, &f->input_count, offsetof(AVFilterLink, dstpad), &f->input_pads, &f->inputs, p); } /** Insert a new output pad for the filter. */ static inline void avfilter_insert_outpad(AVFilterContext *f, unsigned index, AVFilterPad *p) { avfilter_insert_pad(index, &f->output_count, offsetof(AVFilterLink, srcpad), &f->output_pads, &f->outputs, p); } #endif /* AVFILTER_AVFILTER_H */