time remapping in final cut pro

7/31/2019 Time Remapping in Final Cut Pro

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Time Remap - Final Cut ProBy Ken Stone

Constant Speed

Since the beginning FCP has had the ability to change the speed of a clip. Thespeed change applied to a clip is a 'constant' speed change. You can speed upor slow down a clip by a fixed amount only. A 10 second clip can be set to run at50% speed, thus doubling the duration of the clip to 20 seconds. A 10 secondclip can be set to run at 200% thus giving the clip a duration of 5 seconds. FCPalso offers 'Frame Blending'. Frame Blending causes FCP to create or interpolateadditional frames that are needed to accomplish smoother looking motion. Inaddition, there is the ability to select 'reverse' which will run the clip backwards.

You apply Speed changes to a clip on the timeline, by selecting the clip, andfrom the Modify menu > Speed. When a speed change has been applied to a

clip, the length of the clip on the TL will lengthen or shorten to represent the newduration. When the clip changes length on the TL, all surrounding clips will rippleup or down the TL to accommodate the new length of the clip. In addition it ispossible to use 'Fit to Fill' to force a clip to become an exact length, in effect,changing the duration of the clip.

Selected clip on TL

Modify menu > Speed


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Speed dialog box

This feature does work well but is limited, limited to a constant speed for the

entire clip. If you want the clip to have a variable speed, say starting at 0% andfinishing at 200%, this is not possible. The work around has always been to cutthe clip into pieces using the razor blade and then applying a different speed toeach piece, ie; 25%, 75%, 150% then 200%. An inelegant solution. With FCP 4 anew feature has been added, 'Time Remap' and now we can now smoothly andcreatively ramp the speed of a clip.

Variable Speed - Time Remap

Variable speed orTime Remapping, as it is called, gives the us the ability to

produce variable speeds within a clip. We can run the motion faster, slower orboth, make the motion stop, run backwards or even produce a still frame. Forexample, a clip can start playing in 'slow mo', speed up, then run backwards,then run forwards, then backwards again, speeding up and slowing down all thewhile. Well, you follow my drift.

Time Remap is quite different than 'Duration'. Duration uses a dialog box toenter a speed change for the entire clip, Time Remap uses tools to change thespeed, either the Pen tool or the Time Remap tool. Time Remapping work can bedone in two different locations in the FCP interface; in the timeline using the'Remap' tool or in a new section in the Motions tab of the Viewer window called

'Time Remap', using the Pen tool.

There is an other difference between 'Duration' and 'Time Remap'. WhenDuration is used, the length of the clip changes on the timeline to reflect theduration change of that clip. With Time Remap the duration of the clip does notchange. This is important to understand. If a clip runs for 10 seconds, no matterhow many speed changes, starts, stops, freeze frames or reverse motion, thatare applied to the clip, the run time for the clip will always be 10 seconds. Time


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Remapping does not change the overall duration of a clip.

So how is this possible? Here's how. If you slow the clip down in one place,somewhere else in the clip the speed is increased to compensate for the slowdown. If the start of the clip runs slowly, then later the clip will run faster. It's an

equal trade off. The need for Time Remap to use this speed trade off schemedoes have it's limitations, discussed later in this article. While Time Remappingalters the speed of the video portion of the clip, it leaves the audio portionunaffected. You would not want to Time Remap a clip of a 'talking head'. (grin)

So how does Time Remap work?

Easy, we can now Keyframe speed. And keyframing speed is no different thankeyframing 'scale', 'rotation' or 'center'. No kidding folks that's it. Park yourplayhead on a frame in the Canvas where you want to have a speed changeoccur (or forward/reverse) and set a keyframe using the Pen tool. Drag the very

last keyframe of the clip (the anchor) up to increases the speed of the clip, drag itdown to decreases the speed. Drag down far enough and the clip stops, evenfurther and the clip starts to run in reverse. Move the keyframe left or right tochange its position in the timeline. This is how Time Remapping is done in theMotion tab. Time Remapping in the timeline Keyframe Editor is done in the sameway, as we will see later.

Time Remap in the Motion tab

New to FCP 4 is The Time Remap section, with it's 'keyframe graph', found inthe Motion tab in the Viewer window. Place a clip on the timeline and then double

click to load it into the Viewer, select the Motions tab and open the Time Remapsection. As shown below, this is what your clip will look like when you first openthe section. The default setting is 'Constant Speed' and if played as is, the clipwill play at normal speed all the way through. There are two keyframes, one atthe start of the clip and one at the end, these two keyframes act as anchorpoints, if your clip has handles there will be two keyframes at each end. You willnote that the green keyframe line does not run horizontally as it does with otherparameters in the Motion tab. The layout of this graph is different than otherMotions graphs. The vertical axis shows the frame count starting with the firstframe at the bottom and the last frame of the clip at the top of the graph. Thehorizontal axis represents the timeline.


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In addition, the Time Remap section in the Motion tab displays the velocity ofyour clip at the playhead location (below left). In the Keyframe graph, click andhold on a keyframe this will produce a yellow tip box that displays the framenumber that the keyframe is set on (below right).

*It is the angle of the green keyframe line that determines both the speed of themotion in a clip and the direction that the clip runs, either forwards or reverse.

Simple really. The first illustration below shows the green keyframe line runningat a 45 degree angle. 45 degrees represents Constant speed and as such is thedefault setting. Click on the last keyframe and drag up past 45 degrees (number2 below) and the clip will run faster. Drag the keyframe below the 45 degree line(number 3 below) and the clip runs slower . When the keyframe line is horizontal(number 4 below) there will be no motion, a freeze frame. When the greenkeyframe line is running down hill (number 5 below) the clip will run in reverse.


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Constant speed

Faster speed

Slower speed


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Stop motion freeze frame

Reverse motion

When you first open the Time Remap keyframe graph 'Setting' defaults toConstant Speed. After you set your first keyframe and change it's position this

'Setting' will change to Variable. The illustrations above have 'Setting' at ConstantSpeed. Control click on the keyframe that you set and select smooth. Thekeyframe line turns in to a curve (shown below), a gradualacceleration/deceleration. In addition, there is a Bezier handle on both keyframesfor addition manipulation of the curve.

Variable forward speed


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Variable reverse speed

Variable - Bezier handle

Okay, lets do some Time Remapping. I have a clip shot in New York. A lady,sitting on a bench outside a coffee shop reaches out her hand to a dog that iswalking by. The dog pays her no mind and keeps on walking.


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I want to have a little fun with this clip. At that point where the lady reaches out topet the dog I want the motion to stop and run in reverse till the dog is almost outof the frame. Then I want the motion to run forwards up to that same point wherethe lady reaches out to the dog. Again, I want the motion to stop and run inreverse. Then, finally, have the dog walk completely by the lady.

1. Drop the clip into the timeline and double click the clip to load in to the Viewer.Open the Motion tab > open the Time Remap section.

2. While viewing the clip in the Canvas, move the playhead to the position wherethe lady is reaching out to the dog. In the Time Remap section, in the keyframegraph, the playhead line will intersect the green keyframe line. Using the Pentool, set a keyframe at the intersection of the two lines in the graph. Click on thelast keyframe at the end of the clip and pull it down. When the keyframe line isrunning down hill the clip is running in reverse. Try to angle the keyframe line at45 degrees if you want normal reverse speed.


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Reaching out

Lines intersect

Keyframe set


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Pull keyframe line down

3. Now, using the right arrow key, advance the playhead. As the playhead isadvancing to the right and the green keyframe line is running down hill, the clip isreversing. Continue until the dog is almost out of the frame. Set a keyframe atthis intersection. Click on the keyframe at the bottom of the keyframe line and

drag back up. This will cause the clip to start playing forward .

Dog almost out of shot

Set new keyframe


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Pull the keyframe line back up

4. Using the right arrow, advance further down the timeline until you are onceagain at that frame where the lady is reaching down to the dog. Set a keyframeand drag the keyframe at the top of the keyframe line back down. We are nowrunning in reverse again.

Reaching out again

Set new keyframe


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Pull the keyframe line back down

5. Advance further down the timeline until the dog is once more almost out offrame. Set a keyframe and drag the keyframe at the bottom of the keyframe lineback up, returning motion to forward. You will notice that I try to keep the up anddown running sections of the keyframe line at a 45 degree angle. This is because

I want the motion to run at close to normal speed.

Dog almost out of shot

Set new keyframe


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Pull the keyframe line back up

6. Once you have set you basic keyframes you can further adjust them. Placingthe Pen tool cursor on top of any keyframe turns it into a + and you can click anddrag the keyframe to a new location. In addition, you can control click on akeyframe and select 'Smooth'. This will turn the straight keyframe line in to a

curve, a smoothing of the speed change at the keyframe. You will be providedwith Bezier handles.

Now lets do some speed ramps in the Time Remap section of the Motion tab. Itis the same process used above to run a clip forwards and backwards. While

viewing in the Canvas window move the playhead to find the frame that you wantyour speed change to start. Set a keyframe then drag the last keyframe up ordown to effect the speed change. Move your playhead to the next frame youwant to have a speed change and set another keyframe and adjust the greenkeyframe line. Continue til done.


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Open in Time Remap

section

Keyframe - drag upfor faster speed

Keyframe - drag downfor slower speed


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Keyframe - drag upfor normal speed

Control click Smoothset Bezier handles

Time Remap in the timeline

Time Remapping in the timeline is exactly the same as working in the Motiontab. The timeline has been rebuilt to accommodate the Time Remap feature.There is now a workspace beneath the clip called the 'Keyframe Editor'. Thisworkspace is where Time Remapping is done. Other Motion attributes can bekeyframed in the Keyframe Editor as well. At the bottom of the Keyframe Editor isthe Speed Indicator bar which graphically displays 'Tics', representing frames ofthe clip. And a new tool has been added, the Time Remap tool.

Lets set up the timeline 'Time Remap' features. Place a clip onto the Timeline(below left). Click on the 'Clip Keyframe Control' button lower left hand side of the

timeline (red arrow below center). The clip portion of the timeline will expandvertically revealing the 'Keyframe Editor' space (red arrow below right).


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Control click on the 'Clip Keyframe Control', select Video and select the MotionBars as well as Speed Indicators (below left). The Keyframe Editor will nowdisplay the 'Speed Indicator bar' with it's Tics (red arrow below center). Once youhave set your first keyframe the Blue Motion bar will appear with a blue keyframe(red arrow below right).

Control click anywhere in the Keyframe Editor, the space between the clip andthe Speed Indicator bar, Select Time Remap > Time Graph (red arrow belowleft). This will produce a blue keyframe line, the same as the keyframe line foundin the Motion tab. At default, the Keyframe Editor has limited vertical heightmaking work in the Keyframe Editor difficult, everything is just too small. Moveyour cursor just to the left of the Keyframe Editor space, it will turn into a up/downarrow and display 'Keyframe Editor Size' (red arrow below center). Click and dragup to resize the height of the Keyframe Editor. As you drag a thin gray verticalline will will appear showing you the amount of size increase (red arrow belowright). Drag up as far as you need to give yourself enough room to work properly.

As the Keyframe Editor now takes up a great deal more vertical space on thetimeline you may want to drag down the Video/Audio separator bar to better seethe Keyframe Editor.


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A fully expanded Keyframe Editor (shown below) looks exactly the same as thegraph found in the Motion tab > Time Remap section, that because it is thesame. Working in one space will automatically update the Keyframe graph in theother space and you can have both open at the same time. You will work in theKeyframe Editor using the Pen tool and using the same procedures as working inthe Motion tab > Time Remap section, Smooth and Bezier handles are availablehere as well.

As I said, working in either the Motion tab > Time Remap section or in theKeyframe Editor in the timeline uses the same workflow and the same tool, thePen tool. There is yet another way to Time Remap in the timeline. Thisproceedure uses the Time Remap tool. Select the 'Time Remap' tool from thetool palette (below left). As you can see I have been using another new feature inFCP 4 - Buttons and I have placed a Time Remap tool button on my timeline(below right).


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The Time Remap tool does not work in the Keyframe Editor space but rather isused on the clip itself in the timeline. This can be done for a quick speed changeor the fact that you do not wish to open the Keyframe Editor and lose the screenspace. The Remap tool does the same job as the Pen tool. In the Motion tab,click with the Pen tool to set a keyframe, in the timeline click on the clip with theRemap tool to set a keyframe. In the Motion tab when the Pen tool is placed overa keyframe it turns into a + and you are able to drag the keyframe. In thetimeline, place the Remap tool over a keyframe, hold down the Option key andyou are able to drag the keyframe.

With The Time Remap tool selected place the tool cursor over the clip (belowleft). Holding down the Shift key, scrub through the clip. The Canvas window willdisplay as you drag. Find the frame where you want your speed change to start.Click to set a keyframe, continue to hold and you will be presented with theyellow tip box showing information and speed. As you have not yet dragged withthe time Remap tool you will see that Speed Left and right are both showing100% speed (below right).

After you have set a keyframe drag it to the left, this will slow the motion on theleft hand side of the keyframe (and speed it up on the right). In the yellow tip boxbelow, you will see that the left speed is now 63% and that the right speed is144%. The speed tic indicators (below red arrows) on the left are now furtherapart demonstrating that the clip will run slower over that portion of the clip. Thespeed tic indicators on the right are now closer together showing that the clip willplay faster when on that portion of the clip. Remember that the duration of theclip does not change, slowing down one part of the clip will necessitate a speed


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up somewhere else. This speed indicator tics are a graphic representation of thatfact.

Dragging to the right has the opposite effect, speeding up the frames on the lefthand side of the selection point and slowing down the frames on the right side.

You can set any number of keyframes and speed up and slow down any numberof times. Just click to set a keyframe and drag. When both the left and rightspeeds are running at a minus percentage (-%) the clip will play in reverse .Reverse direction is demonstrated by red Tics in the speed indicator bar (below).


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Limitations

Time Remap is not the end all, be all, of time mapping tools. It has its limitations.The fact that Time Remap works by trading off speed changes (every speedchange must have an opposite speed change) limits the effects that you might

want to achieve. It means that if you want to make a speed change at one placein the clip, FCP is going to make an opposite speed change somewhere else inthe clip. Not exactly what you had in mind. If you want to start a clip at normalspeed and then accelerate it to 300% by the end of the clip, you can't.Somewhere in that clip the speed will have to slow down to compensate for the300% increase.

I have a workaround for this limitation so that you can achieve the effects youwant. You'll need to have extra media surrounding the portion of the clip youwant to effect, not talking handles here, I'm talking about lots of extra footageinside the In and Out points. Place the clip with extra footage on the timeline and

set Markers where you want your finished clip to begin and end (red arrowsbelow).

With the Time Remap section of the Motion tab open you will see the twoMarkers at the top. Move your playhead to the first Marker and set a keyframe(green arrow below). You will see in the Speed box that the speed at this point is100% (red arrow below).


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Now move your playhead to the second Marker, set a keyframe (green arrowbelow) and pull the keyframe up until you have a speed of 300% as shown in thespeed box (red arrow below).


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Now render your Time Remap effect, you may want to 'Smooth' your keyframesfirst. Back on the timeline get out the trusty Razor Blade tool and cut at the twomarkers (below left). Delete the unwanted head and tail of the clip (below right).

You might expect that changing the speed inside a clip would also change theduration of the clip to reflect the speed change. Unlike 'Duration' which doeschange the length of the clip, with Time Remap, this is not the case. The fact thatTime Remap can not reflect speed changes by altering the length of the clip onthe timeline is the cause of this limitation.

Conclusion

Up until this time we have had to rely on third party plugins to do TimeRemapping. FCP 4 now has its own Time Remap feature. When you havefinished with your Remap effect you can save it as a Favorite just like any othermotion effect. I personally prefer doing my Time Remap work in the Motion tab.There are a number of steps that you must go through to prepare the timeline forTime Remapping work. There is a new feature in FCP 4, 'Save Track Layout' butunfortunately, at least for me, it does not save my custom timeline Time Remap

Layout completely. The size and position of the Keyframe Editor and 'TimeGraph' are not saved. Of the three ways to do Time Remap work I find using theTime Remap tool directly on a clip in the timeline to be rather cumbersome. TimeRemap works well despite it's limitations and gives us the ability to do someexciting motion effects and right from inside the FCP interface.

Some good news (well for me). Running a dual 800 set to RT Safe and playbackquality at Medium I get real time out firewire. It is so great to be able to view


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these effects on NTSC or PAL as you build them.

Enjoy,

--ken

copyright www.kenstone.net 2003

All screen captures, images, and textual references are the property and trademark of theircreators/owners/publishers.

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