Transition abstract service class. More...

#include <mlt_transition.h>

Inheritance diagram for mlt_transition_s:

Public Member Functions
void	mlt_transition_close (mlt_transition self)
	Close and destroy the transition. More...

int	mlt_transition_connect (mlt_transition self, mlt_service producer, int a_track, int b_track)
	Connect a transition with a producer's a and b tracks. More...

int	mlt_transition_get_a_track (mlt_transition self)
	Get the index of the a track. More...

int	mlt_transition_get_b_track (mlt_transition self)
	Get the index of the b track. More...

mlt_position	mlt_transition_get_in (mlt_transition self)
	Get the in point. More...

mlt_position	mlt_transition_get_length (mlt_transition self)
	Get the duration. More...

mlt_position	mlt_transition_get_out (mlt_transition self)
	Get the out point. More...

mlt_position	mlt_transition_get_position (mlt_transition self, mlt_frame frame)
	Get the position within the transition. More...

double	mlt_transition_get_progress (mlt_transition self, mlt_frame frame)
	Get the percent complete. More...

double	mlt_transition_get_progress_delta (mlt_transition self, mlt_frame frame)
	Get the second field incremental progress. More...

int	mlt_transition_init (mlt_transition self, void *child)
	Initialize a new transition. More...

mlt_transition	mlt_transition_new ()
	Create and initialize a new transition. More...

mlt_frame	mlt_transition_process (mlt_transition self, mlt_frame a_frame, mlt_frame b_frame)
	Process the frame. More...

mlt_properties	mlt_transition_properties (mlt_transition self)
	Get the properties interface. More...

mlt_service	mlt_transition_service (mlt_transition self)
	Get the service class interface. More...

void	mlt_transition_set_in_and_out (mlt_transition self, mlt_position in, mlt_position out)
	Set the starting and ending time for when the transition is active. More...

void	mlt_transition_set_tracks (mlt_transition self, int a_track, int b_track)
	Change the track indices of a transition. More...

Public Member Functions inherited from mlt_service_s
void	mlt_service_apply_filters (mlt_service self, mlt_frame frame, int index)
	Recursively apply attached filters. More...

int	mlt_service_attach (mlt_service self, mlt_filter filter)
	Attach a filter. More...

mlt_cache_item	mlt_service_cache_get (mlt_service self, const char *name)
	Get an object from a service's cache. More...

int	mlt_service_cache_get_size (mlt_service self, const char *name)
	Get the current maximum size of the named cache. More...

void	mlt_service_cache_put (mlt_service self, const char name, void data, int size, mlt_destructor destructor)
	Put an object into a service's cache. More...

void	mlt_service_cache_set_size (mlt_service self, const char *name, int size)
	Set the number of items to cache for the named cache. More...

void	mlt_service_close (mlt_service self)
	Destroy a service. More...

int	mlt_service_connect_producer (mlt_service self, mlt_service producer, int index)
	Connect a producer to the service. More...

mlt_service	mlt_service_consumer (mlt_service self)
	Obtain the consumer a service is connected to. More...

int	mlt_service_detach (mlt_service self, mlt_filter filter)
	Detach a filter. More...

int	mlt_service_disconnect_all_producers (mlt_service self)
	Remove the all the attached producers. More...

int	mlt_service_disconnect_producer (mlt_service self, int index)
	Remove the N-th producer. More...

mlt_filter	mlt_service_filter (mlt_service self, int index)
	Retrieve an attached filter. More...

int	mlt_service_filter_count (mlt_service self)
	Get the number of filters attached. More...

int	mlt_service_get_frame (mlt_service self, mlt_frame_ptr frame, int index)
	Obtain a frame. More...

mlt_service	mlt_service_get_producer (mlt_service self)
	Get the first connected producer. More...

mlt_service_type	mlt_service_identify (mlt_service self)
	Identify the subclass of the service. More...

int	mlt_service_init (mlt_service self, void *child)
	Initialize a service. More...

int	mlt_service_insert_producer (mlt_service self, mlt_service producer, int index)
	Insert a producer connected to the service. More...

void	mlt_service_lock (mlt_service self)
	Acquire a mutual exclusion lock on this service. More...

int	mlt_service_move_filter (mlt_service self, int from, int to)
	Reorder the attached filters. More...

mlt_service	mlt_service_producer (mlt_service self)
	Obtain the producer a service is connected to. More...

mlt_profile	mlt_service_profile (mlt_service self)
	Retrieve the profile. More...

mlt_properties	mlt_service_properties (mlt_service self)
	Return the properties object. More...

void	mlt_service_set_profile (mlt_service self, mlt_profile profile)
	Set the profile for a service. More...

void	mlt_service_unlock (mlt_service self)
	Release a mutual exclusion lock on this service. More...

Public Member Functions inherited from mlt_properties_s
char *	mlt_properties_anim_get (mlt_properties self, const char *name, int position, int length)
	Get a string value by name at a frame position. More...

mlt_color	mlt_properties_anim_get_color (mlt_properties self, const char *name, int position, int length)
	Get a color associated to the name at a frame position. More...

double	mlt_properties_anim_get_double (mlt_properties self, const char *name, int position, int length)
	Get a real number associated to the name at a frame position. More...

int	mlt_properties_anim_get_int (mlt_properties self, const char *name, int position, int length)
	Get an integer associated to the name at a frame position. More...

mlt_rect	mlt_properties_anim_get_rect (mlt_properties self, const char *name, int position, int length)
	Get a rectangle associated to the name at a frame position. More...

int	mlt_properties_anim_set (mlt_properties self, const char name, const char value, int position, int length)
	Set a property to a string at a frame position. More...

int	mlt_properties_anim_set_color (mlt_properties self, const char *name, mlt_color value, int position, int length, mlt_keyframe_type keyframe_type)
	Set a property to an integer value by color at a frame position. More...

int	mlt_properties_anim_set_double (mlt_properties self, const char *name, double value, int position, int length, mlt_keyframe_type keyframe_type)
	Set a property to a real number at a frame position. More...

int	mlt_properties_anim_set_int (mlt_properties self, const char *name, int value, int position, int length, mlt_keyframe_type keyframe_type)
	Set a property to an integer value at a frame position. More...

int	mlt_properties_anim_set_rect (mlt_properties self, const char *name, mlt_rect value, int position, int length, mlt_keyframe_type keyframe_type)
	Set a property to a rectangle value at a frame position. More...

void	mlt_properties_clear (mlt_properties self, const char *name)
	Remove the value for a property. More...

void	mlt_properties_close (mlt_properties self)
	Close a properties object. More...

int	mlt_properties_copy (mlt_properties self, mlt_properties that, const char *prefix)
	Copy all serializable properties that match a prefix to another properties object. More...

int	mlt_properties_count (mlt_properties self)
	Return the number of items in the list. More...

void	mlt_properties_debug (mlt_properties self, const char title, FILE output)
	Output the properties to a file handle. More...

int	mlt_properties_dec_ref (mlt_properties self)
	Decrement the reference count. More...

int	mlt_properties_dir_list (mlt_properties self, const char dirname, const char pattern, int sort)
	Get the contents of a directory. More...

void	mlt_properties_dump (mlt_properties self, FILE *output)
	Dump the properties to a file handle. More...

int	mlt_properties_exists (mlt_properties self, const char *name)
	Check if a property exists. More...

char *	mlt_properties_frames_to_time (mlt_properties self, mlt_position frames, mlt_time_format format)
	Convert a frame count to a time string. More...

int	mlt_properties_from_utf8 (mlt_properties properties, const char name_from, const char name_to)
	Convert UTF-8 property to the locale-defined encoding. More...

char *	mlt_properties_get (mlt_properties self, const char *name)
	Get a string value by name. More...

mlt_animation	mlt_properties_get_animation (mlt_properties self, const char *name)
	Get the animation associated to the name. More...

mlt_color	mlt_properties_get_color (mlt_properties self, const char *name)
	Convert a numeric property to a tuple of color components. More...

void *	mlt_properties_get_data (mlt_properties self, const char name, int length)
	Get a binary data value associated to the name. More...

void *	mlt_properties_get_data_at (mlt_properties self, int index, int *size)
	Get a data value by index. More...

double	mlt_properties_get_double (mlt_properties self, const char *name)
	Get a floating point value associated to the name. More...

int	mlt_properties_get_int (mlt_properties self, const char *name)
	Get an integer associated to the name. More...

int64_t	mlt_properties_get_int64 (mlt_properties self, const char *name)
	Get a 64-bit integer associated to the name. More...

const char *	mlt_properties_get_lcnumeric (mlt_properties self)
	Get the numeric locale for this properties object. More...

char *	mlt_properties_get_name (mlt_properties self, int index)
	Get a property name by index. More...

mlt_position	mlt_properties_get_position (mlt_properties self, const char *name)
	Get a position value associated to the name. More...

mlt_properties	mlt_properties_get_properties (mlt_properties self, const char *name)
	Get a nested properties object by name. More...

mlt_properties	mlt_properties_get_properties_at (mlt_properties self, int index)
	Get a nested properties object by index. More...

mlt_rect	mlt_properties_get_rect (mlt_properties self, const char *name)
	Get a rectangle associated to the name. More...

char *	mlt_properties_get_time (mlt_properties self, const char *name, mlt_time_format format)
	Get a time string associated to the name. More...

char *	mlt_properties_get_value (mlt_properties self, int index)
	Get a property's string value by index. More...

char *	mlt_properties_get_value_tf (mlt_properties self, int index, mlt_time_format time_format)
	Get a property's string value by index (with time format). More...

int	mlt_properties_inc_ref (mlt_properties self)
	Increment the reference count. More...

int	mlt_properties_inherit (mlt_properties self, mlt_properties that)
	Copy all serializable properties to another properties list. More...

int	mlt_properties_init (mlt_properties self, void *child)
	Initialize a properties object that was already allocated. More...

int	mlt_properties_is_anim (mlt_properties self, const char *name)
	Check if a property is animated. More...

int	mlt_properties_is_sequence (mlt_properties properties)
	Determine if the properties list is really just a sequence or ordered list. More...

mlt_properties	mlt_properties_load (const char *filename)
	Create a properties object by reading a .properties text file. More...

void	mlt_properties_lock (mlt_properties self)
	Protect a properties list against concurrent access. More...

void	mlt_properties_mirror (mlt_properties self, mlt_properties that)
	Set a properties list to be a mirror copy of another. More...

mlt_properties	mlt_properties_new ()
	Create a properties object. More...

int	mlt_properties_parse (mlt_properties self, const char *namevalue)
	Set a value by parsing a name=value string. More...

mlt_properties	mlt_properties_parse_yaml (const char *filename)
	Parse a YAML Tiny file by name. More...

int	mlt_properties_pass (mlt_properties self, mlt_properties that, const char *prefix)
	Pass all serializable properties that match a prefix to another properties object. More...

int	mlt_properties_pass_list (mlt_properties self, mlt_properties that, const char *list)
	Copy all properties specified in a comma-separated list to another properties list. More...

void	mlt_properties_pass_property (mlt_properties self, mlt_properties that, const char *name)
	Copy a property to another properties list. More...

int	mlt_properties_preset (mlt_properties self, const char *name)
	Set properties from a preset. More...

int	mlt_properties_ref_count (mlt_properties self)
	Get the reference count. More...

int	mlt_properties_rename (mlt_properties self, const char source, const char dest)
	Rename a property. More...

int	mlt_properties_save (mlt_properties self, const char *filename)
	Save the properties to a file by name. More...

char *	mlt_properties_serialise_yaml (mlt_properties self)
	Serialize a properties list as a string of YAML Tiny. More...

int	mlt_properties_set (mlt_properties self, const char name, const char value)
	Set a property to a string. More...

int	mlt_properties_set_color (mlt_properties self, const char *name, mlt_color color)
	Set a property to an integer value by color. More...

int	mlt_properties_set_data (mlt_properties self, const char name, void value, int length, mlt_destructor destroy, mlt_serialiser serialise)
	Store binary data as a property. More...

int	mlt_properties_set_double (mlt_properties self, const char *name, double value)
	Set a property to a floating point value. More...

int	mlt_properties_set_int (mlt_properties self, const char *name, int value)
	Set a property to an integer value. More...

int	mlt_properties_set_int64 (mlt_properties self, const char *name, int64_t value)
	Set a property to a 64-bit integer value. More...

int	mlt_properties_set_lcnumeric (mlt_properties self, const char *locale)
	Set the numeric locale used for string/double conversions. More...

int	mlt_properties_set_or_default (mlt_properties self, const char name, const char value, const char *def)
	Set or default a property to a string. More...

int	mlt_properties_set_position (mlt_properties self, const char *name, mlt_position value)
	Set a property to a position value. More...

int	mlt_properties_set_properties (mlt_properties self, const char *name, mlt_properties properties)
	Set a property to a nested properties object. More...

int	mlt_properties_set_rect (mlt_properties self, const char *name, mlt_rect value)
	Set a property to a rectangle value. More...

int	mlt_properties_set_string (mlt_properties self, const char name, const char value)
	Set a property to a string. More...

mlt_position	mlt_properties_time_to_frames (mlt_properties self, const char *time)
	Convert a time string to a frame count. More...

void	mlt_properties_unlock (mlt_properties self)
	End protecting a properties list against concurrent access. More...

Data Fields
void *	child
	Protected. More...

void(*	close )(mlt_transition)
	public virtual More...

mlt_frame *	frames
	Private. More...

int	held

pthread_mutex_t	mutex

struct mlt_service_s	parent
	We're implementing service here. More...

mlt_frame(*	process )(mlt_transition, mlt_frame, mlt_frame)
	protected transition method More...

mlt_service	producer
	track and in/out points More...

Data Fields inherited from mlt_service_s
mlt_destructor	close
	the destructor virtual function More...

void *	close_object
	the object supplied to the close virtual function More...

int(*	get_frame )(mlt_service self, mlt_frame_ptr frame, int index)
	Get a frame of data (virtual function). More...

Data Fields inherited from mlt_properties_s
mlt_destructor	close
	the destructor virtual function More...

void *	close_object
	the object supplied to the close virtual function More...

Private Member Functions
static int	transition_get_frame (mlt_service service, mlt_frame_ptr frame, int index)
	Get a frame from a transition. More...

Detailed Description

Transition abstract service class.

A transition may modify the output of a producer based on the output of a second producer.

Property:

a_track the track index (0-based) of a multitrack of the first producer

b_track the track index (0-based) of a multitrack of the second producer

accepts_blanks a flag to indicate if the transition should accept blank frames

always_active a flag to indicate that the in and out points do not apply

_transition_type 1 for video, 2 for audio, 3 for both audio and video

disable Set this to disable the transition while keeping it in the object model.

Member Function Documentation

◆ mlt_transition_close()

void mlt_transition_close ( mlt_transition self )

Close and destroy the transition.

Parameters

self	a transition

◆ mlt_transition_connect()

int mlt_transition_connect	(	mlt_transition	self,
		mlt_service	producer,
		int	a_track,
		int	b_track
	)

Connect a transition with a producer's a and b tracks.

Parameters

self	a transition
producer	a producer
a_track	the track index of the first input
b_track	the track index of the second index

Returns: true on error

◆ mlt_transition_get_a_track()

int mlt_transition_get_a_track ( mlt_transition self )

Get the index of the a track.

Parameters

self	a transition

Returns: the 0-based index of the track of the first producer

◆ mlt_transition_get_b_track()

int mlt_transition_get_b_track ( mlt_transition self )

Get the index of the b track.

Parameters

self	a transition

Returns: the 0-based index of the track of the second producer

◆ mlt_transition_get_in()

mlt_position mlt_transition_get_in ( mlt_transition self )

Get the in point.

Parameters

self	a transition

Returns: the starting time

◆ mlt_transition_get_length()

mlt_position mlt_transition_get_length ( mlt_transition self )

Get the duration.

Parameters

self	a transition

Returns: the duration or zero if unlimited

◆ mlt_transition_get_out()

mlt_position mlt_transition_get_out ( mlt_transition self )

Get the out point.

Parameters

self	a transition

Returns: the ending time

◆ mlt_transition_get_position()

mlt_position mlt_transition_get_position	(	mlt_transition	self,
		mlt_frame	frame
	)

Get the position within the transition.

The position is relative to the in point.

Parameters

self	a transition
frame	a frame

Returns: the position

◆ mlt_transition_get_progress()

double mlt_transition_get_progress	(	mlt_transition	self,
		mlt_frame	frame
	)

Get the percent complete.

Parameters

self	a transition
frame	a frame

Returns: the progress in the range 0.0 to 1.0

◆ mlt_transition_get_progress_delta()

double mlt_transition_get_progress_delta	(	mlt_transition	self,
		mlt_frame	frame
	)

Get the second field incremental progress.

Parameters

self	a transition
frame	a frame

Returns: the progress increment in the range 0.0 to 1.0

◆ mlt_transition_init()

int mlt_transition_init	(	mlt_transition	self,
		void *	child
	)

Initialize a new transition.

Parameters

self	a transition
child	the object of a subclass

Returns: true on error

◆ mlt_transition_new()

mlt_transition mlt_transition_new ( )

Create and initialize a new transition.

Returns: a new transition

◆ mlt_transition_process()

mlt_frame mlt_transition_process	(	mlt_transition	self,
		mlt_frame	a_frame,
		mlt_frame	b_frame
	)

Process the frame.

If we have no process method (unlikely), we simply return the a_frame unmolested.

Parameters

self	a transition
a_frame	a frame from the first producer
b_frame	a frame from the second producer

Returns: a frame

◆ mlt_transition_properties()

mlt_properties mlt_transition_properties ( mlt_transition self )

Get the properties interface.

Parameters

self	a transition

Returns: the transition's properties

See also: MLT_TRANSITION_PROPERTIES

◆ mlt_transition_service()

mlt_service mlt_transition_service ( mlt_transition self )

Get the service class interface.

Parameters

self	a transition

Returns: the service class

See also: MLT_TRANSITION_SERVICE

◆ mlt_transition_set_in_and_out()

void mlt_transition_set_in_and_out	(	mlt_transition	self,
		mlt_position	in,
		mlt_position	out
	)

Set the starting and ending time for when the transition is active.

Parameters

self	a transition
in	the starting time
out	the ending time

◆ mlt_transition_set_tracks()

void mlt_transition_set_tracks	(	mlt_transition	self,
		int	a_track,
		int	b_track
	)

Change the track indices of a transition.

Parameters

a_track	the track index of the first input
b_track	the track index of the second index

◆ transition_get_frame()

static int transition_get_frame	(	mlt_service	service,
		mlt_frame_ptr	frame,
		int	index
	)

private

Get a frame from a transition.

The logic is complex here. A transition is typically applied to frames on the a and b tracks specified in the connect method above and only if both contain valid info for the transition type (this is either audio or image).

However, the fixed a_track may not always contain data of the correct type, eg:

    +---------+                               +-------+
    |c1       |                               |c5     | <-- A(0,1) <-- B(0,2) <-- get frame
    +---------+                     +---------+-+-----+        |          |
                                    |c4         |       <------+          |
             +----------+-----------+-+---------+                         |
             |c2        |c3           |                 <-----------------+
             +----------+-------------+

During the overlap of c1 and c2, there is nothing for the A transition to do, so this results in a no operation, but B is triggered. During the overlap of c2 and c3, again, the A transition is inactive and because the B transition is pointing at track 0, it too would be inactive. This isn't an ideal situation - it's better if the B transition simply treats the frames from c3 as though they're the a track.

For this to work, we cache all frames coming from all tracks between the a and b tracks. Before we process, we determine that the b frame contains something of the right type and then we determine which frame to use as the a frame (selecting a matching frame from a_track to b_track - 1). If both frames contain data of the correct type, we process the transition.

This method is invoked for each track and we return the cached frames as needed. We clear the cache only when the requested frame is flagged as a 'last_track' frame.

Parameters

	service	a service
[out]	frame	a frame by reference
	index	0-based track index

Returns: true on error

Field Documentation

◆ child

void* mlt_transition_s::child

Protected.

◆ close

void(* mlt_transition_s::close) (mlt_transition)

public virtual

◆ frames

mlt_frame* mlt_transition_s::frames

Private.

◆ held

int mlt_transition_s::held

◆ mutex

pthread_mutex_t mlt_transition_s::mutex

◆ parent

struct mlt_service_s mlt_transition_s::parent

We're implementing service here.

◆ process

mlt_frame(* mlt_transition_s::process) (mlt_transition, mlt_frame, mlt_frame)

protected transition method

◆ producer

mlt_service mlt_transition_s::producer

track and in/out points

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

Public Member Functions

Data Fields

Private Member Functions

Detailed Description

Member Function Documentation

◆ mlt_transition_close()

◆ mlt_transition_connect()

◆ mlt_transition_get_a_track()

◆ mlt_transition_get_b_track()

◆ mlt_transition_get_in()

◆ mlt_transition_get_length()

◆ mlt_transition_get_out()

◆ mlt_transition_get_position()

◆ mlt_transition_get_progress()

◆ mlt_transition_get_progress_delta()

◆ mlt_transition_init()

◆ mlt_transition_new()

◆ mlt_transition_process()

◆ mlt_transition_properties()

◆ mlt_transition_service()

◆ mlt_transition_set_in_and_out()

◆ mlt_transition_set_tracks()

◆ transition_get_frame()

Field Documentation

◆ child

◆ close

◆ frames

◆ held

◆ mutex

◆ parent

◆ process

◆ producer