Stefano SabatiniFix a typo.42f72a318 years agoHistory
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/* * filter layer * copyright (c) 2007 Bobby Bingham * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef FFMPEG_AVFILTER_H#define FFMPEG_AVFILTER_H #define LIBAVFILTER_VERSION_MAJOR  0#define LIBAVFILTER_VERSION_MINOR  1#define LIBAVFILTER_VERSION_MICRO  0 #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 <stddef.h>#include "libavcodec/avcodec.h" /** * Returns the LIBAVFILTER_VERSION_INT constant. */unsigned avfilter_version(void); typedef struct AVFilterContext AVFilterContext;typedef struct AVFilterLink    AVFilterLink;typedef struct AVFilterPad     AVFilterPad; /* TODO: look for other flags which may be useful in this structure (interlace * flags, etc) *//** * A reference-counted picture data type used by the filter system.  Filters * should not store pointers to this structure directly, but instead use the * AVFilterPicRef structure below. */typedef struct AVFilterPic{    uint8_t *data[4];           ///< picture data for each plane    int linesize[4];            ///< number of bytes per line    enum PixelFormat format;    ///< colorspace     unsigned refcount;          ///< number of references to this image     /** private data to be used by a custom free function */    void *priv;    /**     * A pointer to the function to deallocate this image 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 AVFilterPic *pic);} AVFilterPic; /** * A reference to an AVFilterPic.  Since filters can manipulate the origin of * a picture to, for example, crop image without any memcpy, the picture 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 AVFilterPicRef{    AVFilterPic *pic;           ///< the picture that this is a reference to    uint8_t *data[4];           ///< picture data for each plane    int linesize[4];            ///< number of bytes per line    int w;                      ///< image width    int h;                      ///< image height     int64_t pts;                ///< presentation timestamp in units of 1/AV_TIME_BASE     AVRational pixel_aspect;    ///< pixel aspect ratio     int perms;                  ///< permissions#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} AVFilterPicRef; /** * Add a new reference to a picture. * @param ref   an existing reference to the picture * @param pmask a bitmask containing the allowable permissions in the new *              reference * @return      a new reference to the picture with the same properties as the *              old, excluding any permissions denied by pmask */AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask); /** * Remove a reference to a picture.  If this is the last reference to the * picture, the picture itself is also automatically freed. * @param ref reference to the picture */void avfilter_unref_pic(AVFilterPicRef *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 AVFilterFormats;struct AVFilterFormats{    unsigned format_count;      ///< number of formats    int *formats;               ///< list of formats     unsigned refcount;          ///< number of references to this list    AVFilterFormats ***refs;    ///< references to this list}; /** * Helper function to create a list of supported formats.  This is intended * for use in AVFilter->query_formats(). * @param len the number of formats supported * @param ... a list of the supported formats * @return    the format list, with no existing references */AVFilterFormats *avfilter_make_format_list(int len, ...); /** * Returns a list of all colorspaces supported by FFmpeg. */AVFilterFormats *avfilter_all_colorspaces(void); /** * Returns 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); /** * Adds *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); /** * Remove *ref as a reference to the format list it currently points to, * deallocate that list if this was the last reference, and set *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 CodecType type;     /**     * Minimum required permissions on incoming buffers.  Any buffers 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 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, AVFilterPicRef *picref);     /**     * Callback function to get a buffer.  If NULL, the filter system will     * handle buffer requests.     *     * Input video pads only.     */    AVFilterPicRef *(*get_video_buffer)(AVFilterLink *link, int perms);     /**     * 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);     /**     * Frame poll callback.  This returns the number of immediately available     * frames. 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, AVFilterPicRef *picref);/** Default handler for end_frame() for video inputs */void avfilter_default_end_frame(AVFilterLink *link);/** Default handler for config_props() for video outputs */int avfilter_default_config_output_link(AVFilterLink *link);/** Default handler for config_props() for video inputs */int avfilter_default_config_input_link (AVFilterLink *link);/** Default handler for get_video_buffer() for video inputs */AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link,                                                  int perms);/** * A helper for query_formats() which sets all links to the same list of * formats. If there are no links hooked to this filter, the list of formats is * freed. */void avfilter_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats);/** Default handler for query_formats() */int avfilter_default_query_formats(AVFilterContext *ctx); /** * Filter definition.  This defines the pads a filter contains, and all the * callback functions used to interact with the filter. */typedef struct{    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 picture references, etc.  This does not need     * to deallocate the AVFilterContext->priv memory itself.     */    void (*uninit)(AVFilterContext *ctx);     /**     * Query formats supported by the filter and its pads. Should set the     * in_formats for links connected to its output pads, and out_formats     * for links connected to its input pads.     *     * Should return zero on success.     */    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} 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}; /** * 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    unsigned int srcpad;        ///< index of the output pad on the source filter     AVFilterContext *dst;       ///< dest filter    unsigned int dstpad;        ///< index of the 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;     int w;                      ///< agreed upon image width    int h;                      ///< agreed upon image height    enum PixelFormat format;    ///< agreed upon image colorspace     /**     * 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;     /**     * The picture reference currently being sent across the link by the source     * filter.  This is used internally by the filter system to allow     * automatic copying of pictures which do not have sufficient permissions     * for the destination.  This should not be accessed directly by the     * filters.     */    AVFilterPicRef *srcpic;     AVFilterPicRef *cur_pic;    AVFilterPicRef *outpic;}; /** * 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 colorspace, 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 picture will *              be requested * @param perms the required access permissions * @return      A reference to the picture.  This must be unreferenced with *              avfilter_unref_pic when you are finished with it. */AVFilterPicRef *avfilter_get_video_buffer(AVFilterLink *link, int perms);

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