LiVES Multitrack Window - mini tutorial
The LiVES user interface consists of two parts: the clip editor which
allows preparation of multiple clips, and is useful for VJ's; and
the multitrack editor which brings those clips together, and is more
useful for video artists.
The clip editor is well described in the
excellent tutorial by Marco de la Cruz.
This guide is about the multitrack window.
There are currently two ways to enter multitrack mode in LiVES. The
first is to record some events by pressing 'r' before playback, and
then after playback, those events can be shown in the multitrack window.
The second way is to have some clips loaded and then press ctrl-m or
Here we will deal with the latter method.
[Note: If you see Tip: - this is for more advanced
users, e.g. on second reading of this document.]
Once you enter multitrack mode, you will see the screen is split
vertically into 3 areas. At the top is the "manipulation area", below
this is the "timeline area", and at the bottom is the "message area".
The manipulation area is split
horizontally into three regions:
- the preview window
- the "polymorph" window
- the context window
as shown here:
Fig. 1: The manipulation area.
The preview window shows
playback and effect previews.
The polymorph window, as its
name suggests, changes
depending on what you are doing. Its modes include:
- clip mode (as seen above) : shows all clips loaded in LiVES, and
allows them to be dragged onto the timeline. You can enter this mode
any time by pressing 'c' (or from the View menu)
- in/out mode : if you double click on a block, the polymorph window
will go into in/out mode. You can adjust the start and end points of a
block using the in/out spinbuttons. If a block is selected (by double
clicking on it) then you can enter this mode by pressing 'i' (or from
the View menu)
- effect mode : if the last action was to apply an effect, and that
effect has parameters, then the polymorph window will go into effect
mode. In this mode, you can set effect parameters and preview frames.
Frame previews are shown in the preview window. You can return to this
mode by editing an effect (TODO).
The context window shows
information relevant to the current action. Look at this window if you
are confused. It might help...maybe...
The timeline area contains the
timeline header, which is a horizontal ruler marked in seconds. It has
a cursor which scrolls during playback, or can be set by clicking in
the timeline header. If you click and drag here, you can set a time region (see below).
It also contains the track area. Here you can see your video tracks and
(TODO !) audio tracks.
Each track has a checkbox for "selected/unselected", then a name and a
layer number, then a blank area which can be filled with video or (TODO
Selected/unselected is used for setting the track part of a region (see
Layers go from layer 0 at the top, (the "front") downwards - towards
the "back". Layer 0 is always the "front" layer, layer 1 is "behind"
this, layer 2 "behind" that, etc. You can add layers at the front or
back, literally as many as you like. Normally you will only see the
front layer, unless you apply a transition or a compositor (see below).
Fig. 2: The timeline area.
At the top of the timeline area are two spinbuttons. These show the
region start and end points (see below for more explanation of regions).
The message area is the same
as in clip editing mode, and shows information about your actions. You
can call up the entire message log from the View menu.
Fig. 3: the message area.
Inserting clips and applying an effect
You can insert a clip by dragging a clip from the polymorph window onto
a timeline track. If the polymorph window is not in clip mode, you can
press 'c' to get there. Drag a clip from the top and release it onto
Tip: Alternately, you can use
the keyboard. ctrl-page-up and ctrl-page-down will cycle through clips.
ctrl-left and ctrl-right will move the timeline cursor. ctrl-up and
ctrl-down can be used to change the current track. ctrl-i will insert
the current clip at the current cursor position in the current track.
In standard insert mode, the insert point must be blank (i.e. free of
other video). If the clip is too long, as many frames as possible will
be inserted. In future there will be more types of insert mode (TODO).
If you have "snap" mode on, any inserted or moved clips will be moved
as far left as possible. You can switch on "snap" mode from the menu
bar. In future there may be different types of "snap" modes.
If you inserted a clip, you can always "undo" it from the Edit menu.
Then switch on snap mode, and insert again.
You can also set the "mouse mode". We will come on to that later, for
now, leave it as "move".
Fig. 4 mouse mode and snap mode.
Fig. 5 Selecting a clip.
Fig. 6 dragging to the timeline
Fig. 7 dropped on the timeline with "snap" on
When you have inserted a clip, it becomes a "block". Blocks are the
smallest unit in the LiVES multitrack editor.
A block can vary from 1 frame to any number of frames. Currently, all
frames in a block must come from the same clip.
Tip: There are two types of
blocks in LiVES - ordered blocks and unordered blocks. Ordered blocks
have incrementing frame numbers, and these are what you get if you
insert a clip from the clip area. Unordered blocks have frame numbers
which jump around. Unordered blocks can be produced by the event
recorder. There is not yet much support for unordered blocks in LiVES,
but there may be in the future.
Now we have inserted a block, we can apply an effect to it. First we
must select the block by double clicking on it. If you do this, you
will see the block gets marked with an "X" and the polymorph window
will enter in/out mode.
Fig. 8 double clicking on a block selects it
Fig. 9 the polymorph window in in/out mode
With the polymorph window in in/out mode, the start and end points can
be adjusted using the spinbuttons. The start and end points can be
anchored in time using the anchor start/end buttons.
Tip: blocks can be split and
deleted by right clicking on them.
With the block still selected we will apply an effect to it. Go to the
effects menu, and select "apply effect to block". We will choose the
"colour correction" effect because it has parameters.
When you click on an effect with parameters, the polymorph window will
go into effect mode. You will also see a frame preview in the preview
Fig. 10 after applying an effect with parameters (colour correction)
We will first set the parameters at the start of the effect. We can do
this by sliding the small slider under the parameters all the way to
Fig. 11 slide the time slider to the left
Tip: notice the timeline cursor
moves with the effect time slider. You can also move the timeline
cursor which will set the effect time slider.
You can then adjust the parameters, and preview them by pressing the
"preview frame" button.
Fig. 12 setting the parameter values
Fig. 13 the "show frame preview" button.
When you are happy with the values, you can press the "Set values at
Fig 14. set values at time
We will now set the values at the end of the effect. Slide the effect
time slider all the way to the right. Then adjust and preview the
values, and when you are happy click on "set values at time" again.
Tip: you can move between
parameter values, and delete parameter settings using the buttons to
the right of the effect time slider. You can also set values at any
time between start and end of the effect.
If you now move the slider back and forth, you should see the values
changing smoothly. This is known as "parameter interpolation". You can
preview at any point by pressing "show frame preview".
If you now play back the layout (by pressing 'p'), you should see the
colours in the clip changing !
You can add more effects on top of the colour correction, and undo
effects using the Edit/Undo menu.
In future there will be ways of deleting, reordering, and editing
Creating a transition
We will now create a transition. First we will move our block down to
layer 1. You can do this simply by dragging and dropping the block onto
the track below. If you still have "snap" on, it will snap to the left
of that track. Also, if you have the menu option "Effects/move effects
with blocks" checked, any block effects will be moved with the block.
Fig. 15: the block is moved to layer 1
Now we will add a second block to layer 0. Make sure the blocks overlap
(this is easier if you have "snap" on). Drag a second clip into layer 0.
Fig. 16: adding a second block
We will now create a region.
In LiVES, a region is a combination of a time region with 1 or more
selected tracks. First we will select our two tracks. You can either
click on the checkbuttons on the left of the tracks, or use the menu
option Selection/Select all video tracks.
Tip: you can also select
tracks using the keyboard. ctrl-space will select/deselect the current track,
and ctrl-up-arrow, ctrl-down-arrow will move the current track up and down.
Fig. 17: two tracks are selected
We will now complete the region by selecting a time region. First we
will choose to select the overlap. We can do this by switching on the
menu option: Selection/Snap to overlap. This will cause selection of
the overlap area between the selected tracks.
Now click on the timeline header inside the overlap, and the region
will expand to cover all of the overlap.
Fig. 18: completed selection of a region.
We can now apply a transition to our region. Go to the menu option
Effects/Apply effect to region, and choose "transitions". For this
tutorial, we will use the "chroma blend" transition. This will give us
a cross-fade between the two tracks.
We will first cross-fade from layer 0 into layer 1.
When you select "chroma blend", the polymorph window will go into
effect mode. As above with an effect, slide the time slider all the way
to the left. Then select "transition in". Transition in means that all of the
front layer (in this case, layer 0) is visible.
Fig. 19: setting the transition in at the start
Don't forget to press "set values at time" !
Now, slide the effect time slider to the right, and click on Transition
Out. Transition Out means that all of the rear layer (in this case,
layer 1) is visible. Then click on "set values at time" again.
Fig. 20: setting the transition at the end
Now when you play back, you will see frames transition from layer 0 to
OK, but what if we want to transition the other way, from layer 1 to
layer 0 ? Simple. Slide the time slider to the left, select Transition
Out, and then "set values at time". Then slide the time slider to the
right, click on Transition In, and "set values at time". That's it !
Applying a compositor
Now we are going to apply a compositor. A compositor takes 2 or more
tracks and mixes them down to a single track. The output is always on
the frontmost layer of the compositor (in future, this will be
adjustable - TODO).
We will start by laying out three clips on three tracks in the
timeline. [You can first clear the timeline by pressing ctrl-e, ctrl-m.]
Now we need to add a third track. You can do this by pressing ctrl-t
(add frame behind) or ctrl-shift-t (add frame in front), or from the
tracks menu. You can drag a clip onto each track.
Fig. 21: LiVES with 3 video tracks
Now we need to create a region to apply our compositor to. First select
all three tracks, either by checking the boxes on the left, or from the
menu option Selection/Select all video tracks.
Fig. 22: three video tracks selected.
Now select a time region by dragging on the timeline header. If
Selection/snap to overlap is on, only the overlap region will be
For this demo, we will have Selection/snap to overlap off.
Fig. 23: three tracks selected and a time region
Now click on Effect/Apply effect to region, and pick "compositors". At
the time of writing there is only one compositor, called "compositor".
Select this. The polymorph window will go into effect mode.
Now, this is where it becomes a little tricky. You need to know where
the timeline cursor is, and also which track is the "current track".
If you look in fig. 23, the current track is layer 2 (because it is a
different colour to the rest). You can change the current track by
clicking on its label, or by using ctrl-up and ctrl-down.
You can also move the timeline cursor by using key combinations ctrl-left-arrow and
ctrl-right-arrow, or by clicking on the timeline header. You can use ctrl-j
(jump) or menu option "Edit/Jump to next block boundary" to jump to the
edge of a block.
Depending on whether there is a frame present or not at the current
time/track coordinate you will see one of two things. If a frame is
present, you will see frame settings (x start, y start, x scale,
yscale, alpha) and the background colour control. If no frame is
present, you will see only the background colour control. Try moving
the timeline cursor and current track so you can see both things.
Fig. 24: compositor parameters when no frame is present
Fig. 25: compositor parameters when a frame is present.
If a frame is present, you can also click and drag on the preview
window to set the xstart, ystart, xscale, yscale and alpha values.
Fig. 26: preview window can be used to "draw on" for the compositor.
Don't forget to click on "set values at time" when you want to set some
Tip: parameters xstart, ystart,
xend, and yend and alpha, are set independently for each track in the
compositor. Clicking on "set values at time" only sets these parameters
for the current track.
These parameters are also interpolated, so for example, you can make a
clip move around, or fade in and out.
Saving and rendering
You can save your layout at any time from the file menu.
You can render your layout from the Render menu, or by pressing ctrl-r.
The rendering is added as a new clip. You can decide whether rendering
returns you to the clip editor, or leaves you in multitrack mode using
the Preferences/Rendering Multitrack settings.
This is just a brief introduction to the multitrack window in LiVES.
There are many other features, for example:
- mouse mode select : changing mouse mode to "select" allows you to
select a region simply by clicking and dragging with the mouse on the
- close gaps : with a region selected, you can close any gaps in it by
pressing ctrl-g or from the Selection menu
- close first gaps : you can also close only the first gaps by pressing
ctrl-f or from the Selection menu
Gap closing is done by moving blocks left
- split selected tracks : you can split all selected tracks at the
- select all : pressing ctrl-a selects the whole timeline (just like in
the clip editor) [but beware of Selection/select overlap]
Note also that the multitrack window is still in development.