FFmpeg/libavfilter/buffersrc.h
Nicolas George b0012de420 lavfi/buffersrc: implement flags.
The PUSH flags is necessary for efficient scheduling;
otherwise there is no feedback when adding frames to
closed paths.

The NO_CHECK_FORMAT is a small optimization that does
not cost much to implement.

The KEEP_REF flag maps to the add/write distinction in
the fork's API.
2013-03-10 13:56:17 +01:00

149 lines
4.6 KiB
C

/*
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVFILTER_BUFFERSRC_H
#define AVFILTER_BUFFERSRC_H
/**
* @file
* Memory buffer source API.
*/
#include "libavcodec/avcodec.h"
#include "avfilter.h"
enum {
/**
* Do not check for format changes.
*/
AV_BUFFERSRC_FLAG_NO_CHECK_FORMAT = 1,
#if FF_API_AVFILTERBUFFER
/**
* Ignored
*/
AV_BUFFERSRC_FLAG_NO_COPY = 2,
#endif
/**
* Immediately push the frame to the output.
*/
AV_BUFFERSRC_FLAG_PUSH = 4,
/**
* Keep a reference to the frame.
* If the frame if reference-counted, create a new reference; otherwise
* copy the frame data.
*/
AV_BUFFERSRC_FLAG_KEEP_REF = 8,
};
/**
* Add buffer data in picref to buffer_src.
*
* @param buffer_src pointer to a buffer source context
* @param picref a buffer reference, or NULL to mark EOF
* @param flags a combination of AV_BUFFERSRC_FLAG_*
* @return >= 0 in case of success, a negative AVERROR code
* in case of failure
*/
int av_buffersrc_add_ref(AVFilterContext *buffer_src,
AVFilterBufferRef *picref, int flags);
/**
* Get the number of failed requests.
*
* A failed request is when the request_frame method is called while no
* frame is present in the buffer.
* The number is reset when a frame is added.
*/
unsigned av_buffersrc_get_nb_failed_requests(AVFilterContext *buffer_src);
#if FF_API_AVFILTERBUFFER
/**
* Add a buffer to the filtergraph s.
*
* @param buf buffer containing frame data to be passed down the filtergraph.
* This function will take ownership of buf, the user must not free it.
* A NULL buf signals EOF -- i.e. no more frames will be sent to this filter.
*
* @deprecated use av_buffersrc_write_frame() or av_buffersrc_add_frame()
*/
attribute_deprecated
int av_buffersrc_buffer(AVFilterContext *s, AVFilterBufferRef *buf);
#endif
/**
* Add a frame to the buffer source.
*
* @param s an instance of the buffersrc filter.
* @param frame frame to be added. If the frame is reference counted, this
* function will make a new reference to it. Otherwise the frame data will be
* copied.
*
* @return 0 on success, a negative AVERROR on error
*
* This function is equivalent to av_buffersrc_add_frame_flags() with the
* AV_BUFFERSRC_FLAG_KEEP_REF flag.
*/
int av_buffersrc_write_frame(AVFilterContext *s, const AVFrame *frame);
/**
* Add a frame to the buffer source.
*
* @param s an instance of the buffersrc filter.
* @param frame frame to be added. If the frame is reference counted, this
* function will take ownership of the reference(s) and reset the frame.
* Otherwise the frame data will be copied. If this function returns an error,
* the input frame is not touched.
*
* @return 0 on success, a negative AVERROR on error.
*
* @note the difference between this function and av_buffersrc_write_frame() is
* that av_buffersrc_write_frame() creates a new reference to the input frame,
* while this function takes ownership of the reference passed to it.
*
* This function is equivalent to av_buffersrc_add_frame_flags() without the
* AV_BUFFERSRC_FLAG_KEEP_REF flag.
*/
int av_buffersrc_add_frame(AVFilterContext *ctx, AVFrame *frame);
/**
* Add a frame to the buffer source.
*
* By default, if the frame is reference-counted, this function will take
* ownership of the reference(s) and reset the frame. This can be controled
* using the flags.
*
* If this function returns an error, the input frame is not touched.
*
* @param buffer_src pointer to a buffer source context
* @param frame a frame, or NULL to mark EOF
* @param flags a combination of AV_BUFFERSRC_FLAG_*
* @return >= 0 in case of success, a negative AVERROR code
* in case of failure
*/
int av_buffersrc_add_frame_flags(AVFilterContext *buffer_src,
AVFrame *frame, int flags);
#endif /* AVFILTER_BUFFERSRC_H */