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...

Data Fields

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/audioconvert.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.
AVFilterFormatsin_formats
 Lists of formats and channel layouts supported by the input and output filters respectively.
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.
enum AVFilterLink:: { ... }  init_state
 stage of the initialization of the link properties (dimensions, etc)
AVFilterBufferRefsrc_buf
 The buffer reference currently being sent across the link by the source filter.
AVFilterBufferRefcur_buf
 The buffer reference to the frame sent across the link by the source filter, which is read by the destination filter.
AVFilterBufferRefout_buf
 The buffer reference to the frame which is sent to output by the source filter.
struct AVFilterPoolpool
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 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; if left to 0/0, will be automatically be copied from the first input of the source filter if it exists.
AVFilterBufferRefpartial_buf
 Buffer partially filled with samples to achieve a fixed/minimum size.
int partial_buf_size
 Size of the partial buffer to allocate.
int min_samples
 Minimum number of samples to filter at once.
int max_samples
 Maximum number of samples to filter at once.
AVFilterBufferRefcur_buf_copy
 The buffer reference currently being received across the link by the destination filter.
int closed
 True if the link is closed.


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.

Definition at line 520 of file avfilter.h.


Member Enumeration Documentation

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

Definition at line 584 of file avfilter.h.


Field Documentation

True if the link is closed.

If set, all attemps of start_frame, filter_samples or request_frame will fail with AVERROR_EOF, and if necessary the reference will be destroyed. If request_frame returns AVERROR_EOF, this flag is set on the corresponding link. It can be set also be set by either the source or the destination filter.

Definition at line 710 of file avfilter.h.

Referenced by avfilter_link_set_closed(), draw_slice(), end_frame(), ff_filter_samples_framed(), ff_request_frame(), ff_start_frame(), and start_frame().

The buffer reference to the frame sent across the link by the source filter, which is read by the destination filter.

It is automatically set up by ff_start_frame().

Depending on the permissions, it may either be the same as src_buf or an automatic copy of it.

It is automatically freed by the filter system when calling ff_end_frame(). In case you save the buffer reference internally (e.g. if you cache it for later reuse), or give it away (e.g. if you pass the reference to the next filter) it must be set to NULL before calling ff_end_frame().

Definition at line 613 of file avfilter.h.

Referenced by add_to_queue(), clear_link(), draw_slice(), end_frame(), end_frame_over(), ff_filter_samples_framed(), ff_start_frame(), process_frame(), scale_slice(), start_frame(), and start_frame_main().

The buffer reference currently being received across the link by the destination filter.

This is used internally by the filter system to allow automatic copying of buffers which do not have sufficient permissions for the destination. This should not be accessed directly by the filters.

Definition at line 698 of file avfilter.h.

Referenced by clear_link(), ff_draw_slice(), and ff_start_frame().

Current timestamp of the link, as defined by the most recent frame(s), in AV_TIME_BASE units.

Definition at line 646 of file avfilter.h.

Referenced by avfilter_config_links(), ff_update_link_current_pts(), heap_bubble_down(), and heap_bubble_up().

Frame rate of the stream on the link, or 1/0 if unknown; if left to 0/0, will be automatically be 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. 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.

Definition at line 663 of file avfilter.h.

Referenced by av_buffersink_get_frame_rate(), avfilter_config_links(), config_input(), config_output(), config_output_props(), config_props(), and movie_config_output_props().

Graph the filter belongs to.

Definition at line 640 of file avfilter.h.

Referenced by ff_avfilter_graph_config_pointers(), ff_update_link_current_pts(), and process_frame().

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.

Definition at line 562 of file avfilter.h.

Referenced by avfilter_free(), insert_conv_filter(), movie_query_formats(), pick_format(), pick_formats(), query_formats(), and swap_sample_fmts_on_filter().

Lists of channel layouts and sample rates used for automatic negotiation.

Definition at line 569 of file avfilter.h.

Referenced by avfilter_free(), movie_query_formats(), pick_format(), query_formats(), and swap_samplerates_on_filter().

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

Referenced by avfilter_config_links().

Maximum number of samples to filter at once.

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

Definition at line 689 of file avfilter.h.

Referenced by av_buffersink_set_frame_size().

Minimum number of samples to filter at once.

If filter_samples() 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.

Definition at line 683 of file avfilter.h.

Referenced by av_buffersink_set_frame_size(), and ff_filter_samples().

The buffer reference to the frame which is sent to output by the source filter.

If no start_frame callback is defined on a link, ff_start_frame() will automatically request a new buffer on the first output link of the destination filter. The reference to the buffer so obtained is stored in the out_buf field on the output link.

It can also be set by the filter code in case the filter needs to access the output buffer later. For example the filter code may set it in a custom start_frame, and access it in draw_slice.

It is automatically freed by the filter system in ff_end_frame().

Definition at line 633 of file avfilter.h.

Referenced by clear_link(), default_start_frame(), draw_send_bar_slice(), draw_slice(), draw_slice_main(), end_frame(), end_frame_main(), end_last_frame(), ff_inplace_start_frame(), scale_slice(), start_frame(), try_push_frame(), and try_start_frame().

Buffer partially filled with samples to achieve a fixed/minimum size.

Definition at line 668 of file avfilter.h.

Referenced by ff_filter_samples(), and ff_request_frame().

Size of the partial buffer to allocate.

Must be between min_samples and max_samples.

Definition at line 674 of file avfilter.h.

Referenced by av_buffersink_set_frame_size(), and ff_filter_samples().

Definition at line 635 of file avfilter.h.

Referenced by ff_default_get_video_buffer().

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.

Definition at line 581 of file avfilter.h.

Referenced by join_request_frame(), request_frame(), and return_audio_frame().

The buffer reference currently being sent across the link by the source filter.

This is used internally by the filter system to allow automatic copying of buffers which do not have sufficient permissions for the destination. This should not be accessed directly by the filters.

Definition at line 597 of file avfilter.h.

Referenced by clear_link(), ff_draw_slice(), and ff_start_frame().


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

Generated on Fri Oct 26 02:50:14 2012 for FFmpeg by  doxygen 1.5.8