ffmpeg/libavfilter/buffersink.h

150 lines
5.0 KiB
C

/*
* 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_BUFFERSINK_H
#define AVFILTER_BUFFERSINK_H
/**
* @file
* memory buffer sink API for audio and video
*/
#include "avfilter.h"
/**
* Struct to use for initializing a buffersink context.
*/
typedef struct {
const enum AVPixelFormat *pixel_fmts; ///< list of allowed pixel formats, terminated by AV_PIX_FMT_NONE
} AVBufferSinkParams;
/**
* Create an AVBufferSinkParams structure.
*
* Must be freed with av_free().
*/
AVBufferSinkParams *av_buffersink_params_alloc(void);
/**
* Struct to use for initializing an abuffersink context.
*/
typedef struct {
const enum AVSampleFormat *sample_fmts; ///< list of allowed sample formats, terminated by AV_SAMPLE_FMT_NONE
const int64_t *channel_layouts; ///< list of allowed channel layouts, terminated by -1
const int *channel_counts; ///< list of allowed channel counts, terminated by -1
int all_channel_counts; ///< if not 0, accept any channel count or layout
} AVABufferSinkParams;
/**
* Create an AVABufferSinkParams structure.
*
* Must be freed with av_free().
*/
AVABufferSinkParams *av_abuffersink_params_alloc(void);
/**
* Set the frame size for an audio buffer sink.
*
* All calls to av_buffersink_get_buffer_ref will return a buffer with
* exactly the specified number of samples, or AVERROR(EAGAIN) if there is
* not enough. The last buffer at EOF will be padded with 0.
*/
void av_buffersink_set_frame_size(AVFilterContext *ctx, unsigned frame_size);
/**
* Tell av_buffersink_get_buffer_ref() to read video/samples buffer
* reference, but not remove it from the buffer. This is useful if you
* need only to read a video/samples buffer, without to fetch it.
*/
#define AV_BUFFERSINK_FLAG_PEEK 1
/**
* Tell av_buffersink_get_buffer_ref() not to request a frame from its input.
* If a frame is already buffered, it is read (and removed from the buffer),
* but if no frame is present, return AVERROR(EAGAIN).
*/
#define AV_BUFFERSINK_FLAG_NO_REQUEST 2
/**
* Get an audio/video buffer data from buffer_sink and put it in bufref.
*
* This function works with both audio and video buffer sinks.
*
* @param buffer_sink pointer to a buffersink or abuffersink context
* @param flags a combination of AV_BUFFERSINK_FLAG_* flags
* @return >= 0 in case of success, a negative AVERROR code in case of
* failure
*/
int av_buffersink_get_buffer_ref(AVFilterContext *buffer_sink,
AVFilterBufferRef **bufref, int flags);
/**
* Get the number of immediately available frames.
*/
int av_buffersink_poll_frame(AVFilterContext *ctx);
/**
* Get the frame rate of the input.
*/
AVRational av_buffersink_get_frame_rate(AVFilterContext *ctx);
/**
* @defgroup libav_api Libav API
* @{
*/
/**
* Get a buffer with filtered data from sink and put it in buf.
*
* @param ctx pointer to a context of a buffersink or abuffersink AVFilter.
* @param buf pointer to the buffer will be written here if buf is non-NULL. buf
* must be freed by the caller using avfilter_unref_buffer().
* Buf may also be NULL to query whether a buffer is ready to be
* output.
*
* @return >= 0 in case of success, a negative AVERROR code in case of
* failure.
*/
int av_buffersink_read(AVFilterContext *ctx, AVFilterBufferRef **buf);
/**
* Same as av_buffersink_read, but with the ability to specify the number of
* samples read. This function is less efficient than av_buffersink_read(),
* because it copies the data around.
*
* @param ctx pointer to a context of the abuffersink AVFilter.
* @param buf pointer to the buffer will be written here if buf is non-NULL. buf
* must be freed by the caller using avfilter_unref_buffer(). buf
* will contain exactly nb_samples audio samples, except at the end
* of stream, when it can contain less than nb_samples.
* Buf may also be NULL to query whether a buffer is ready to be
* output.
*
* @warning do not mix this function with av_buffersink_read(). Use only one or
* the other with a single sink, not both.
*/
int av_buffersink_read_samples(AVFilterContext *ctx, AVFilterBufferRef **buf,
int nb_samples);
/**
* @}
*/
#endif /* AVFILTER_BUFFERSINK_H */