FFmpeg
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AVFilterLink Struct Reference

A link between two filters. More...

#include <avfilter.h>

Public Types

enum  { AVLINK_UNINIT = 0, AVLINK_STARTINIT, AVLINK_INIT }
 stage of the initialization of the link properties (dimensions, etc) More...
 

Public Attributes

AVFilterContextsrc
 source filter
 
AVFilterPadsrcpad
 output pad on the source filter
 
AVFilterContextdst
 dest filter
 
AVFilterPaddstpad
 input pad on the dest filter
 
enum AVMediaType type
 filter media type
 
int w
 agreed upon image width
 
int h
 agreed upon image height
 
AVRational sample_aspect_ratio
 agreed upon sample aspect ratio
 
uint64_t channel_layout
 channel layout of current buffer (see libavutil/channel_layout.h)
 
int sample_rate
 samples per second
 
int format
 agreed upon media format
 
AVRational time_base
 Define the time base used by the PTS of the frames/samples which will pass through this link. More...
 
AVFilterFormatsin_formats
 Lists of formats and channel layouts supported by the input and output filters respectively. More...
 
AVFilterFormatsout_formats
 
AVFilterFormatsin_samplerates
 Lists of channel layouts and sample rates used for automatic negotiation.
 
AVFilterFormatsout_samplerates
 
struct AVFilterChannelLayoutsin_channel_layouts
 
struct AVFilterChannelLayoutsout_channel_layouts
 
int request_samples
 Audio only, the destination filter sets this to a non-zero value to request that buffers with the given number of samples should be sent to it. More...
 
enum AVFilterLink:: { ... }  init_state
 stage of the initialization of the link properties (dimensions, etc)
 
struct AVFilterGraphgraph
 Graph the filter belongs to.
 
int64_t current_pts
 Current timestamp of the link, as defined by the most recent frame(s), in link time_base units.
 
int64_t current_pts_us
 Current timestamp of the link, as defined by the most recent frame(s), in AV_TIME_BASE units.
 
int age_index
 Index in the age array.
 
AVRational frame_rate
 Frame rate of the stream on the link, or 1/0 if unknown or variable; if left to 0/0, will be automatically copied from the first input of the source filter if it exists. More...
 
AVFramepartial_buf
 Buffer partially filled with samples to achieve a fixed/minimum size.
 
int partial_buf_size
 Size of the partial buffer to allocate. More...
 
int min_samples
 Minimum number of samples to filter at once. More...
 
int max_samples
 Maximum number of samples to filter at once. More...
 
int channels
 Number of channels.
 
unsigned flags
 Link processing flags.
 
int64_t frame_count_in
 Number of past frames sent through the link.
 
int64_t frame_count_out
 
void * frame_pool
 A pointer to a FFFramePool struct.
 
int frame_wanted_out
 True if a frame is currently wanted on the output of this filter. More...
 
AVBufferRefhw_frames_ctx
 For hwaccel pixel formats, this should be a reference to the AVHWFramesContext describing the frames.
 
char reserved [0xF000]
 Internal structure members. More...
 

Detailed Description

A link between two filters.

This contains pointers to the source and destination filters between which this link exists, and the indexes of the pads involved. In addition, this link also contains the parameters which have been negotiated and agreed upon between the filter, such as image dimensions, format, etc.

Applications must not normally access the link structure directly. Use the buffersrc and buffersink API instead. In the future, access to the header may be reserved for filters implementation.

Member Enumeration Documentation

§ anonymous enum

anonymous enum

stage of the initialization of the link properties (dimensions, etc)

Enumerator
AVLINK_UNINIT 

not started

AVLINK_STARTINIT 

started, but incomplete

AVLINK_INIT 

complete

Member Data Documentation

§ frame_rate

AVRational AVFilterLink::frame_rate

Frame rate of the stream on the link, or 1/0 if unknown or variable; if left to 0/0, will be automatically copied from the first input of the source filter if it exists.

Sources should set it to the best estimation of the real frame rate. If the source frame rate is unknown or variable, set this to 1/0. Filters should update it if necessary depending on their function. Sinks can use it to set a default output frame rate. It is similar to the r_frame_rate field in AVStream.

§ frame_wanted_out

int AVFilterLink::frame_wanted_out

True if a frame is currently wanted on the output of this filter.

Set when ff_request_frame() is called by the output, cleared when a frame is filtered.

§ in_formats

AVFilterFormats* AVFilterLink::in_formats

Lists of formats and channel layouts supported by the input and output filters respectively.

These lists are used for negotiating the format to actually be used, which will be loaded into the format and channel_layout members, above, when chosen.

§ max_samples

int AVFilterLink::max_samples

Maximum number of samples to filter at once.

If filter_frame() is called with more samples, it will split them.

§ min_samples

int AVFilterLink::min_samples

Minimum number of samples to filter at once.

If filter_frame() is called with fewer samples, it will accumulate them in partial_buf. This field and the related ones must not be changed after filtering has started. If 0, all related fields are ignored.

§ partial_buf_size

int AVFilterLink::partial_buf_size

Size of the partial buffer to allocate.

Must be between min_samples and max_samples.

§ request_samples

int AVFilterLink::request_samples

Audio only, the destination filter sets this to a non-zero value to request that buffers with the given number of samples should be sent to it.

AVFilterPad.needs_fifo must also be set on the corresponding input pad. Last buffer before EOF will be padded with silence.

§ reserved

char AVFilterLink::reserved[0xF000]

Internal structure members.

The fields below this limit are internal for libavfilter's use and must in no way be accessed by applications.

§ time_base

AVRational AVFilterLink::time_base

Define the time base used by the PTS of the frames/samples which will pass through this link.

During the configuration stage, each filter is supposed to change only the output timebase, while the timebase of the input link is assumed to be an unchangeable property.


The documentation for this struct was generated from the following file: