Hello, this is Eric D. Kirk for mamoworld.com and welcome to this tutorial where we create
the following time remapping effect with Premiere Pro and After Effects
The key idea is to time remap the clip in sync with the beats of the music so that
the video is moving at the beats and stopping in-between them.
In Premiere Pro we first do a beat detection using our extension BeatEdit.
All you need to do for this is open an audio file in BeatEdit and the beat detection
starts automatically.
Now we make sure that “clip markers” is selected here and then
click the “create markers” button to generate markers for all detected beats.
A great thing about clip markers is that they are saved as meta data
directly inside the audio file.
So if we import the same audio file in After Effects and drag it into a composition,
you can see that the markers are in After Effects now, too.
I already have my time lapse clip here in the composition, but currently is is playing
at normal speed.
Now we make sure that we are at the first frame, right-click on the clip and choose
“time->freeze frame”.
This creates this “Time Remap” property here with a single hold keyframe to freeze
at the first frame.
Now you could start keyframing this time remap property to move a bit forward in time
at each beat marker.
But since this would be very tedious, we use an expression instead.
The Movement Modifier Bundle of our extension iExpressions contains some ready to use expressions
that are perfect for this purpose.
So I start iExpressions which you find in the Window menu once it is installed and open
the iExpressions library.
This library contains more than 120 expressions in various categories.
In the “Movement Modifier” category we have the section “Marker” which contains
several expressions that can change properties based on markers.
You might think that the “Time Remap at Marker” iExpression is what we need, but
this expression will play the same segment of the clip at each marker.
Hence, it is only useful if you want to loop exactly the same frames at each beat.
But what we want is to move forward in time at each beat, or in other words we want to
increment the time at each marker.
We choose the “Increment at Marker 1D” expression, the 2D and 3D variants are useful
if you want to change the position or scale of a layer at each beat, for example.
The big difference between iExpressions and normal expressions is that iExpressions come
with such a nice interface where you can customize them without writing any expressions code.
The “Increment at Marker” value, for example, controls how much the value should change
at each beat.
We set it to 0.2 which means that the time will move forward 0.2 seconds on each beat.
Also, since the markers are not on our footage but on the music layer, we choose
“use markers from: other layer”
and enter the name of the layer with our markers here.
Now we select the time remap property and apply the expression.
Let’s take a look at what we created so far.
The video plays nicely in sync with the beat but the movements at the beat are very abrupt.
To change this, we add some fade in.
Let’s set the fade in to 5 frames and apply the expression again.
Now it is less abrupt.
You can make it even more smooth by choosing an exponential fade type.
And this is our final result:
Again, this is Eric D. Kirk for mamoworld.com - see you next time!