/* * 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" enum EOFAction {    EOF_ACTION_REPEAT,    EOF_ACTION_ENDALL,    EOF_ACTION_PASS}; /* * TODO * 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: set the on_event * callback, then call ff_framesync_activate() from the filter's activate * callback. */ /** * 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 {     /**     * 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;     /**     * Parent filter context.     */    AVFilterContext *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;     int opt_repeatlast;    int opt_shortest;    int opt_eof_action; } FFFrameSync; /** * Pre-initialize a frame sync structure. * * It sets the class pointer and inits the options to their default values. * The entire structure is expected to be already set to 0. * This step is optional, but necessary to use the options. */void ff_framesync_preinit(FFFrameSync *fs); /** * Initialize a frame sync structure. * * The entire structure is expected to be already set to 0 or preinited. * * @param  fs      frame sync structure to initialize * @param  parent  parent AVFilterContext object * @param  nb_in   number of inputs * @return  >= 0 for success or a negative error code */int ff_framesync_init(FFFrameSync *fs, AVFilterContext *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); /** * 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); /** * Examine the frames in the filter's input and try to produce output. * * This function can be the complete implementation of the activate * method of a filter using framesync. */int ff_framesync_activate(FFFrameSync *fs); /** * Initialize a frame sync structure for dualinput. * * Compared to generic framesync, dualinput assumes the first input is the * main one and the filtering is performed on it. The first input will be * the only one with sync set and generic timeline support will just pass it * unchanged when disabled. * * Equivalent to ff_framesync_init(fs, parent, 2) then setting the time * base, sync and ext modes on the inputs. */int ff_framesync_init_dualinput(FFFrameSync *fs, AVFilterContext *parent); /** * @param f0  used to return the main frame * @param f1  used to return the second frame, or NULL if disabled * @return  >=0 for success or AVERROR code * @note  The frame returned in f0 belongs to the caller (get = 1 in * ff_framesync_get_frame()) while the frame returned in f1 is still owned * by the framesync structure. */int ff_framesync_dualinput_get(FFFrameSync *fs, AVFrame **f0, AVFrame **f1); /** * Same as ff_framesync_dualinput_get(), but make sure that f0 is writable. */int ff_framesync_dualinput_get_writable(FFFrameSync *fs, AVFrame **f0, AVFrame **f1); const AVClass *ff_framesync_child_class_iterate(void **iter); #define FRAMESYNC_DEFINE_PURE_CLASS(name, desc, func_prefix, options) \static const AVClass name##_class = {                                 \    .class_name          = desc,                                      \    .item_name           = av_default_item_name,                      \    .option              = options,                                   \    .version             = LIBAVUTIL_VERSION_INT,                     \    .category            = AV_CLASS_CATEGORY_FILTER,                  \    .child_class_iterate = ff_framesync_child_class_iterate,          \    .child_next          = func_prefix##_child_next,                  \} /* A filter that uses the *_child_next-function from this macro * is required to initialize the FFFrameSync structure in AVFilter.preinit * via the *_framesync_preinit function defined alongside it. */#define FRAMESYNC_AUXILIARY_FUNCS(func_prefix, context, field)        \static int func_prefix##_framesync_preinit(AVFilterContext *ctx)      \{                                                                     \    context *s = ctx->priv; \    ff_framesync_preinit(&s->field); \    return 0; \} \static void *func_prefix##_child_next(void *obj, void *prev)          \{                                                                     \    context *s = obj; \    return prev ? NULL : &s->field; \} #define FRAMESYNC_DEFINE_CLASS_EXT(name, context, field, options)     \FRAMESYNC_AUXILIARY_FUNCS(name, context, field)                       \FRAMESYNC_DEFINE_PURE_CLASS(name, #name, name, options) #define FRAMESYNC_DEFINE_CLASS(name, context, field)                  \FRAMESYNC_DEFINE_CLASS_EXT(name, context, field, name##_options) #endif /* AVFILTER_FRAMESYNC_H */