Filter abstract service class. More...

#include <mlt_filter.h>

Inheritance diagram for mlt_filter_s:

Public Member Functions
void	mlt_filter_close (mlt_filter self)
	Close and destroy the filter.
int	mlt_filter_connect (mlt_filter self, mlt_service producer, int index)
	Connect this filter to a producers track.
mlt_position	mlt_filter_get_in (mlt_filter self)
	Get the in point.
mlt_position	mlt_filter_get_length (mlt_filter self)
	Get the duration.
mlt_position	mlt_filter_get_length2 (mlt_filter self, mlt_frame frame)
	Get the duration.
mlt_position	mlt_filter_get_out (mlt_filter self)
	Get the out point.
mlt_position	mlt_filter_get_position (mlt_filter self, mlt_frame frame)
	Get the position within the filter.
double	mlt_filter_get_progress (mlt_filter self, mlt_frame frame)
	Get the percent complete.
int	mlt_filter_get_track (mlt_filter self)
	Return the track that this filter is operating on.
int	mlt_filter_init (mlt_filter self, void *child)
	Initialize a new filter.
mlt_filter	mlt_filter_new ()
	Create a new filter and initialize it.
mlt_frame	mlt_filter_process (mlt_filter self, mlt_frame frame)
	Process the frame.
mlt_properties	mlt_filter_properties (mlt_filter self)
	Get the filter properties.
mlt_service	mlt_filter_service (mlt_filter self)
	Get the service class interface.
void	mlt_filter_set_in_and_out (mlt_filter self, mlt_position in, mlt_position out)
	Set the starting and ending time.
Data Fields
void *	child
	Protected.
void(*	close )(mlt_filter)
	public virtual
struct mlt_service_s	parent
	We're implementing service here.
mlt_frame(*	process )(mlt_filter, mlt_frame)
	protected filter method
Private Member Functions
static int	filter_get_frame (mlt_service service, mlt_frame_ptr frame, int index)
	Get a frame from this filter.

Detailed Description

Filter abstract service class.

A filter is a service that may modify the output of a single producer.

Property:

track the index of the track of a multitrack on which the filter is applied

service a reference to the service to which this filter is attached. Currently this is not cleared when the filter is detached.

Member Function Documentation

static int filter_get_frame	(	mlt_service	service,
		mlt_frame_ptr	frame,
		int	index
	)		`[private]`

Get a frame from this filter.

Parameters:

	service	a service
[out]	frame	a frame by reference
	index	as determined by the producer

Returns:: true on error

void mlt_filter_close ( mlt_filter self )

Close and destroy the filter.

Parameters:

self a filter

int mlt_filter_connect	(	mlt_filter	self,
		mlt_service	producer,
		int	index
	)

Connect this filter to a producers track.

Note that a filter only operates on a single track, and by default it operates on the entirety of that track.

Parameters:

self	a filter
producer	the producer to which to connect this filter
index	which of potentially multiple producers to this service (0 based)

mlt_position mlt_filter_get_in ( mlt_filter self )

Get the in point.

Parameters:

self a filter

Returns:: the start time for the filter relative to the producer

mlt_position mlt_filter_get_length ( mlt_filter self )

Get the duration.

Parameters:

self a filter

Returns:: the duration or zero if unlimited

mlt_position mlt_filter_get_length2	(	mlt_filter	self,
		mlt_frame	frame
	)

Get the duration.

This version works with filters with no explicit in and out by getting the length of the frame's producer.

Parameters:

self	a filter
frame	a frame from which to get its producer

Returns:: the duration or zero if unlimited

mlt_position mlt_filter_get_out ( mlt_filter self )

Get the out point.

Parameters:

self a filter

Returns:: the ending time for the filter relative to the producer

mlt_position mlt_filter_get_position	(	mlt_filter	self,
		mlt_frame	frame
	)

Get the position within the filter.

The position is relative to the in point. This will only be valid once mlt_filter_process is called.

Parameters:

self	a filter
frame	a frame

Returns:: the position

double mlt_filter_get_progress	(	mlt_filter	self,
		mlt_frame	frame
	)

Get the percent complete.

This will only be valid once mlt_filter_process is called.

Parameters:

self	a filter
frame	a frame

Returns:: the progress in the range 0.0 to 1.0

int mlt_filter_get_track ( mlt_filter self )

Return the track that this filter is operating on.

Parameters:

self a filter

Returns:: true on error

int mlt_filter_init	(	mlt_filter	self,
		void *	child
	)

Initialize a new filter.

Parameters:

self	a filter
child	the object of a subclass

Returns:: true if there was an error

mlt_filter mlt_filter_new ( )

Create a new filter and initialize it.

Returns:: a new filter

mlt_frame mlt_filter_process	(	mlt_filter	self,
		mlt_frame	frame
	)

Process the frame.

When fetching the frame position in a subclass process method, the frame's position is relative to the filter's producer - not the filter's in point or timeline.

Parameters:

self	a filter
frame	a frame

Returns:: a frame

mlt_properties mlt_filter_properties ( mlt_filter self )

Get the filter properties.

Parameters:

self a filter

Returns:: the properties list for the filter

See also:: MLT_FILTER_PROPERTIES

mlt_service mlt_filter_service ( mlt_filter self )

Get the service class interface.

Parameters:

self a filter

Returns:: the service parent class

See also:: MLT_FILTER_SERVICE

void mlt_filter_set_in_and_out	(	mlt_filter	self,
		mlt_position	in,
		mlt_position	out
	)

Set the starting and ending time.

Parameters:

self	a filter
in	the time relative to the producer at which start applying the filter
out	the time relative to the producer at which to stop applying the filter