/* * 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; /** * Get the class for the framesync object. */ const AVClass *ff_framesync_get_class(void); /** * 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); #define FRAMESYNC_DEFINE_CLASS(name, context, field) \ static int name##_framesync_preinit(AVFilterContext *ctx) { \ context *s = ctx->priv; \ ff_framesync_preinit(&s->field); \ return 0; \ } \ static const AVClass *name##_child_class_next(const AVClass *prev) { \ return prev ? NULL : ff_framesync_get_class(); \ } \ static void *name##_child_next(void *obj, void *prev) { \ context *s = obj; \ s->fs.class = ff_framesync_get_class(); /* FIXME */ \ return prev ? NULL : &s->field; \ } \ static const AVClass name##_class = { \ .class_name = #name, \ .item_name = av_default_item_name, \ .option = name##_options, \ .version = LIBAVUTIL_VERSION_INT, \ .category = AV_CLASS_CATEGORY_FILTER, \ .child_class_next = name##_child_class_next, \ .child_next = name##_child_next, \ } #endif /* AVFILTER_FRAMESYNC_H */