/* * Copyright (c) 2013 Nicolas George * * 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_FRAMESYNC_H#define AVFILTER_FRAMESYNC_H #include "bufferqueue.h" /* * TODO * Callback-based API similar to dualinput. * Export convenient options. */ /** * This API is intended as a helper for filters that have several video * input and need to combine them somehow. If the inputs have different or * variable frame rate, getting the input frames to match requires a rather * complex logic and a few user-tunable options. * * In this API, when a set of synchronized input frames is ready to be * procesed is called a frame event. Frame event can be generated in * response to input frames on any or all inputs and the handling of * situations where some stream extend beyond the beginning or the end of * others can be configured. * * The basic working of this API is the following: * * - When a frame is available on any input, add it using *   ff_framesync_add_frame(). * * - When a frame event is ready to be processed (i.e. after adding a frame *   or when requested on input): *   - call ff_framesync_next(); *   - if fs->frame_ready is true, process the frames; *   - call ff_framesync_drop(). */ /** * Stream extrapolation mode * * Describe how the frames of a stream are extrapolated before the first one * and after EOF to keep sync with possibly longer other streams. */enum FFFrameSyncExtMode {     /**     * Completely stop all streams with this one.     */    EXT_STOP,     /**     * Ignore this stream and continue processing the other ones.     */    EXT_NULL,     /**     * Extend the frame to infinity.     */    EXT_INFINITY,}; /** * Input stream structure */typedef struct FFFrameSyncIn {     /**     * Queue of incoming AVFrame, and NULL to mark EOF     */    struct FFBufQueue queue;     /**     * Extrapolation mode for timestamps before the first frame     */    enum FFFrameSyncExtMode before;     /**     * Extrapolation mode for timestamps after the last frame     */    enum FFFrameSyncExtMode after;     /**     * Time base for the incoming frames     */    AVRational time_base;     /**     * Current frame, may be NULL before the first one or after EOF     */    AVFrame *frame;     /**     * Next frame, for internal use     */    AVFrame *frame_next;     /**     * PTS of the current frame     */    int64_t pts;     /**     * PTS of the next frame, for internal use     */    int64_t pts_next;     /**     * Boolean flagging the next frame, for internal use     */    uint8_t have_next;     /**     * State: before first, in stream or after EOF, for internal use     */    uint8_t state;     /**     * Synchronization level: frames on input at the highest sync level will     * generate output frame events.     *     * For example, if inputs #0 and #1 have sync level 2 and input #2 has     * sync level 1, then a frame on either input #0 or #1 will generate a     * frame event, but not a frame on input #2 until both inputs #0 and #1     * have reached EOF.     *     * If sync is 0, no frame event will be generated.     */    unsigned sync; } FFFrameSyncIn; /** * Frame sync structure. */typedef struct FFFrameSync {    const AVClass *class;    void *parent;     /**     * Number of input streams     */    unsigned nb_in;     /**     * Time base for the output events     */    AVRational time_base;     /**     * Timestamp of the current event     */    int64_t pts;     /**     * Callback called when a frame event is ready     */    int (*on_event)(struct FFFrameSync *fs);     /**     * Opaque pointer, not used by the API     */    void *opaque;     /**     * Index of the input that requires a request     */    unsigned in_request;     /**     * Synchronization level: only inputs with the same sync level are sync     * sources.     */    unsigned sync_level;     /**     * Flag indicating that a frame event is ready     */    uint8_t frame_ready;     /**     * Flag indicating that output has reached EOF.     */    uint8_t eof;     /**     * Pointer to array of inputs.     */    FFFrameSyncIn *in; } FFFrameSync; /** * Initialize a frame sync structure. * * The entire structure is expected to be already set to 0. * * @param  fs      frame sync structure to initialize * @param  parent  parent object, used for logging * @param  nb_in   number of inputs * @return  >= 0 for success or a negative error code */int ff_framesync_init(FFFrameSync *fs, void *parent, unsigned nb_in); /** * Configure a frame sync structure. * * Must be called after all options are set but before all use. * * @return  >= 0 for success or a negative error code */int ff_framesync_configure(FFFrameSync *fs); /** * Free all memory currently allocated. */void ff_framesync_uninit(FFFrameSync *fs); /** * Add a frame to an input * * Typically called from the filter_frame() method. * * @param fs     frame sync structure * @param in     index of the input * @param frame  input frame, or NULL for EOF */int ff_framesync_add_frame(FFFrameSync *fs, unsigned in, AVFrame *frame); /** * Prepare the next frame event. * * The status of the operation can be found in fs->frame_ready and fs->eof. */void ff_framesync_next(FFFrameSync *fs); /** * Drop the current frame event. */void ff_framesync_drop(FFFrameSync *fs); /** * Get the current frame in an input. * * @param fs      frame sync structure * @param in      index of the input * @param rframe  used to return the current frame (or NULL) * @param get     if not zero, the calling code needs to get ownership of *                the returned frame; the current frame will either be *                duplicated or removed from the framesync structure */int ff_framesync_get_frame(FFFrameSync *fs, unsigned in, AVFrame **rframe,                           unsigned get); /** * Process one or several frame using the on_event callback. * * @return  number of frames processed or negative error code */int ff_framesync_process_frame(FFFrameSync *fs, unsigned all);  /** * Accept a frame on a filter input. * * This function can be the complete implementation of all filter_frame * methods of a filter using framesync. */int ff_framesync_filter_frame(FFFrameSync *fs, AVFilterLink *inlink,                              AVFrame *in); /** * Request a frame on the filter output. * * This function can be the complete implementation of all filter_frame * methods of a filter using framesync if it has only one output. */int ff_framesync_request_frame(FFFrameSync *fs, AVFilterLink *outlink); #endif /* AVFILTER_FRAMESYNC_H */