Kdenlive/Manual/Transitions/Composite/en: Difference between revisions

Latest revision as of 14:28, 6 September 2020

Other languages:

Composite Transition

The Composite transition combines the video data from two video tracks into one. This transition is used in combination with Alpha Channel information supplied by one of the Alpha Manipulation Effects or by the use of a Wipe File. This Alpha Channel data describes how the data from the two video tracks should be combined. Until you define some alpha channel data using an Alpha Manipulation Effect or a Wipe File, changes in the Composite transition settings will have no visible effect.

Note: The disadvantages of the Composite transition are: luma bleed, and less precise position control. When compared to Affine, the Composite transition, it does not support rotation or skewing but it is much faster, albeit at the cost of luma bleed.

Alpha operations

Alpha operation options are Over, And, Or and Xor

Operation Over

The clip with alpha information is located on the top track: the selected color acquires transparency.
The clip with alpha information is located on the bottom track: we see only the top clip.

Operation And

The clip with the alpha information is located on the top track: the selected color becomes transparent.
The clip with alpha information is located on the bottom track: everything in the image becomes transparent, except for the selected color.

Operation Or clears any alpha information

Operation Xor

The clip with alpha information is located on the top track: everything in the image becomes transparent, except for the selected color.
The clip with alpha information is located on the bottom track: the selected color acquires transparency.

Tutorial 1

See this tutorial that describes how to use:

Alpha Manipulation -> Blue Screen

rotoscoping

Composite Transition.

Crop and Transform -> Pan and Zoom effect

Enhancement -> Sharpen Effect

Alpha Manipulation -> Alpha Operations

Tutorial 2 - composite transition and Blue Screen

Tutorial showing how to use the "Blue screen" function, composite transition and Keyframes to animate one image moving over another in the Kdenlive video editor.

Tutorial 3 - Video Masks

This tutorial uses the Composite transition and a custom video mask (a.k.a. a Wipe File or matte) to create an effect where you can make it appear that one video is playing on the screen of a still of a computer monitor.

The mask/matte is created with GIMP.

Save your mattes to /usr/share/kdenlive/lumas.

It would appear that you need to stop and restart Kdenlive in order for it to pick up new matte/wipe files saved in the above directory.

There appears to be a defect in this functionality which means that when the composite is on 100% Opacity, the wipe file does not work. You need to change it to 99% to make the effect kick in.

Screenshot of Composite transition using a custom wipe file to mask out a section of video - as described in Tutorial 3.

Aspirational goal - a compositing experiment made using detonation films free sample effects.

Warning: video below may be inappropriate for some users. {{#ev:youtube|vo-xntF1bns}}

@@ Line 5: / Line 5: @@
 The Composite transition combines the video data from two video tracks into one. This transition is used in combination with Alpha Channel information supplied by one of the [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha_manipulation#General_Information_about_Alpha_Manipulation|Alpha Manipulation Effects]] or by the use of a [[Special:myLanguage/Kdenlive/Manual/Transitions/Composite#Tutorial_3_-_Video_Masks| Wipe File]]. This Alpha Channel data describes how the data from the two video tracks should be combined. Until you define some alpha channel data using an [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha_manipulation#General_Information_about_Alpha_Manipulation|Alpha Manipulation Effect]] or a Wipe File, changes in the Composite transition settings will have no visible effect.
-Note: Some of the Composite transition functionality can also be supplied by the [[Special:MyLanguage/Kdenlive/Manual/Transitions/Affine|Affine]] transition. The Affine transition also does not suffer from the "green tinge" bug reported by some. (Mantis #[http://www.kdenlive.org/mantis/view.php?id=2759 2759])
+Note: The disadvantages of the '''Composite''' transition are: luma bleed, and less precise position control. When compared to '''Affine''', the '''Composite''' transition, it does not support rotation or skewing but it is much faster, albeit at the cost of luma bleed.
+==== Alpha operations ====
 [[File:Composite transition showing alpha channel operation options.png|400px|left]]
@@ Line 12: / Line 14: @@
 <br style="clear: both;"/>
-[[File:Over alpha operation.png|300px|left]]
+Operation '''Over'''
-''Over'' Operation produces this (after you deal with the messed up preview - see [[Special:myLanguage/Kdenlive/Manual/Transitions/Composite#Hint_for_previewing_the_alpha_manipulation_effects| hint]]   below).
+# The clip with alpha information is located on the top track: the selected color acquires transparency.
-<br style="clear: both;"/>
+# The clip with alpha information is located on the bottom track: we see only the top clip.
-[[File:Xor alpha operation.png|300px|left]]
-''Xor'' Operation produces this (after you deal with the messed up preview - see  [[Special:myLanguage/Kdenlive/Manual/Transitions/Composite#Hint_for_previewing_the_alpha_manipulation_effects| hint]] below).
-<br style="clear: both;"/><br />
-I am not sure I understand what the ''And'' and ''Or'' Alpha operations do.
-==== Hint for previewing the alpha manipulation effects ====
+[[File:alpha_operation_Over.png]]
-The preview in the Project Monitor goes all strange when you select the Composite transition in the timeline or the Video 1 track in the timeline. (This is fixed on mantis #[http://www.kdenlive.org/mantis/view.php?id=2990 2990]  [http://quickgit.kde.org/?p=kdenlive.git&a=commit&h=e692395e685251de32144abfdf85b6c57319c41b 24 Feb 2013])
+Operation '''And'''
+# The clip with the alpha information is located on the top track: the selected color becomes transparent.
+# The clip with alpha information is located on the bottom track: everything in the image becomes transparent, except for the selected color.
-[[File:Weird preview look.png|400px|left]]
+[[File:alpha_operation_And.png]]
-What the Project Monitor looks like when you have just selected the Composite transition in the timeline. This is not what the rendered video will look like.
+Operation '''Or''' clears any alpha information
-To get a look at what the video will render as, you need to click Video 1 and then Video 2 in the timeline.
+[[File:alpha_operation_Or.png]]
-<br style="clear: both;"/>
-[[File:Two tracks composite transition with alpha info.png|400px|left]]
+Operation '''Xor'''
+# The clip with alpha information is located on the top track: everything in the image becomes transparent, except for the selected color.
+# The clip with alpha information is located on the bottom track: the selected color acquires transparency.
-What the preview looks like once you select Video 2 in the timeline. This is what the rendered file will look like
+[[File:alpha_operation_Xor.png]]
-<br style="clear: both;"/>
-<br />
 ==== Tutorial 1 ====
@@ Line 44: / Line 40: @@
 See this [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha_manipulation/Blue_Screen#Tutorial_2|tutorial]] that describes how to use:
-* Alpha Manipution -> [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha_manipulation/Blue_Screen|Blue Screen]]
+* Alpha Manipulation -> [[Special:myLanguage/Kdenlive/Manual/Effects/Alpha_manipulation/Blue_Screen|Blue Screen]]
 * [[Special:MyLanguage/Kdenlive/Manual/Effects/Alpha_manipulation/Rotoscoping|rotoscoping]]
@@ Line 68: / Line 64: @@
 The mask/matte is created with '''GIMP'''.
-Save your mattes to <tt>/usr/share/kde4/apps/kdenlive/lumas</tt>.
+Save your mattes to <tt>/usr/share/kdenlive/lumas</tt>.
 It would appear that you need to stop and restart '''Kdenlive''' in order for it to pick up new matte/wipe files saved in the above directory.
@@ Line 85: / Line 81: @@
 Aspirational goal -  a compositing experiment made using detonation films free sample effects.
+'''Warning''': video below may be inappropriate for some users.
 {{#ev:youtube|vo-xntF1bns}}