Retiming Behaviors

Retiming behaviors are applied to image sequences, QuickTime movies, and clone layers in order to change their timing. Retiming effects include creating hold frames, changing playback rate, reversing a clip, creating stutter or strobe effects, and so on.

Important: Retiming behaviors can only be applied to QuickTime movies, image sequences, or clone layers. In other words, a Retiming behavior cannot be applied to a particle emitter, but it can be applied to an instance of the particle emitter. For more information on cloning layers, see Making Clone Layers.

Retiming Behaviors Versus Timing Controls in the Inspector

When a clip is selected, a group of Timing parameters appears in the Properties tab of the Inspector. These controls allow you to do some of the same effects as the Retiming behaviors, such as slowing down or speeding up, looping, or reversing a clip; however, the Timing controls affect the entire clip. The beauty of the Retiming behaviors is that you can define which portion of the clip is affected by the behavior. Any timing changes made to a clip using the Inspector’s Timing controls are respected by the Retiming behaviors. For example, if you changed the speed of the clip to 50% in the Timing parameters, a Retiming behavior uses that half-speed clip as its source. For more information on Timing controls in the Inspector, see Retiming.

The following sections cover the Retiming behaviors:

Flash Frame

This behavior randomly inserts a user-defined range of random frames (adjacent to the current frame) into the playback of a clip.

Parameters in the Inspector
  • Random Frames: A slider that sets the probability that a frame within the duration of the behavior is replaced with a random frame. When this value is set to 0, no random frames are inserted. When set to 100, every frame is random. The default value is 10%.
  • Frame Range: A slider that defines the range from which the random frames are chosen, based around the current frame. The default value is 10 frames.
  • Duration: A slider that sets the duration of the sequence of random frames. The default value is 1, which means 1 random frame is inserted at a time. When Duration is set to 30, for example, 30-frame sequences (chosen from the Frame Range) are randomly inserted. The Duration value overrides the Random Frame count (so that a new random frame does not interrupt the sequence).
  • Random Seed: A button that lets you pick a new random seed number. This number is used to randomly generate new values, based on the other parameters of this behavior.
HUD Controls

The HUD contains the Random Frames, Frame Range, Duration, and Random Seed parameters.

Hold Frame

The Hold Frame behavior holds the frame at the behavior’s In point for the duration of the behavior. The clip continues playing normally after the behavior’s Out point. For example, if the Hold Frame behavior begins at frame 60 and ends at frame 300, the clip plays normally until frame 59, frame 60 is held for 240 frames, and then normal playback resumes—frame 61 of the clip—at frame 301.

The Hold behavior is always applied at the current frame, rather than at the start of the object.

Parameters in the Inspector
  • Offset: A slider that sets the offset for the hold frame. When set to 0 (the default), the frame at the start of the behavior is the hold frame. When set to 60, however, the frame at the start of the behavior (the hold frame) is the start frame plus 60 frames. This parameter is measured in frames.

    Tip: Flickering may occur if the Hold Frame behavior is applied to interlaced footage. To avoid this, ensure that Field Order is properly set in the Inspector. To change field order, select the footage in the Media tab of the Project pane, show the Media tab in the Inspector, then choose a field order option from the Field Order pop-up menu.

HUD Controls

The HUD contains the Offset parameter.

Loop

This behavior loops a segment of the clip within the duration of the behavior. The loop’s starting frame is derived from the start frame of the behavior. For example, if the behavior is applied at the start of a clip, and Loop Duration is set to 30, the first 30 frames of the clip loop repeatedly until the end of the behavior. At the end of the behavior, normal playback resumes from the frame at the end of the loop duration.

Parameters in the Inspector
  • Loop Duration: A slider that sets the duration of the looped frames. The default value is 30 frames.
HUD Controls

The HUD contains the Loop Duration parameter.

Ping Pong

This behavior “ping-pongs” a segment of the clip within the duration of the behavior. The ping-pong’s starting frame is derived from the start frame of the behavior. For example, if the behavior is applied at the start of a clip, and Duration is set to 30, the first 30 frames of the clip play forward, then play in reverse, then forward, and so on until the end of the behavior. At the end of the behavior, normal playback resumes.

Parameters in the Inspector
  • Duration: A slider that sets the duration of the ping-pong frames. The default value is 30 frames.
HUD Controls

The HUD contains the Loop Duration parameter.

Replay

The Replay behavior resets the playhead at the beginning of the behavior to a specific frame, and then plays the clip normally from that frame. The clip plays back normally after the end of the behavior. This allows you to trigger playback of the clip at different times, without requiring multiple copies of the movie object.

Parameters in the Inspector
  • Start Time: A slider that sets the start frame from which to replay the clip. The default is frame 1.
HUD Controls

The HUD contains the Start From and Start Time parameters.

Reverse

This behavior plays the clip or image sequence in reverse.

Parameters in the Inspector

There are no parameters for this behavior.

HUD Controls

There are no parameters for this behavior.

Reverse Loop

This behavior loops a segment of the clip in reverse within the duration of the behavior. If Loop Duration is set to 30 and the behavior begins at frame 1, frames 1–30 are played in reverse, then frames 31–60 are played in reverse, frames 61–90 are played in reverse, and so on.

Tip: To achieve a nice stutter effect, set Loop Duration to 2.

Parameters in the Inspector
  • Loop Duration: A slider that sets the duration of the looped frames to be played in reverse. The default value is 30 frames.
HUD Controls

The HUD contains the Loop Duration parameter.

Scrub

Like the Scrub filter, the Scrub behavior moves a virtual playhead around a clip, allowing you to change the timing of the clip without moving it in the Timeline. Additionally, the Scrub behavior allows you to animate the offset parameter using keyframes or parameter behaviors, often with interesting results. Try applying the Oscillate behavior to the Frame offset, with the Offset From parameter set to Current Frame.

Note: You can also apply parameter behaviors to the Retime Value parameter in the Timing controls for the image itself. The Timing controls are located in the Properties tab. Time Remap must be set to Variable Speed in order to access the Retime Value parameter.

Important: Scrub does not affect clip audio.

Parameters in the Inspector
  • Frame Offset: Sets the offset of the virtual playhead.
HUD Controls

The HUD contains the Frame Offset and Offset From parameters.

Set Speed

This behavior allows you to change the speed (playback rate) of a clip. The speed specified in the behavior begins at the behavior’s In point and exists for the duration of the behavior. The clip continues playing at its default speed after the behavior’s Out point. For example, if the Set Speed behavior begins at frame 60 and ends at frame 300, the clip plays normally until frame 59, plays back at the rate specified in the behavior from frame 60 to frame 300, and then resumes its default playback speed at frame 301. You can apply an “ease-in” or “ease-out” effect to the speed change.

Parameters in the Inspector
  • Speed: A slider that sets the speed of the clip as a percentage. The default is 100% (the clip’s normal speed). A Speed setting of 50% plays the clip at half speed.

    Note: The Speed parameter can be keyframed to create variable playback rate changes.

  • Ease In Time: A slider that sets the number of frames over which the ease in to the speed change occurs (from the start of the behavior). The default value is 20 frames.
  • Ease In Curve: A slider that defines the curvature of the ramp when easing into the speed change. A value of 0 creates a sharp transition to the new speed; a value of 100 creates the smoothest ease in to the new speed. The default is 50%.
  • Ease Out Time: A slider that sets the number of frames over which the ease out of the speed change occurs (from the end of the behavior). The default value is 20 frames.
  • Ease Out Curve: A slider that defines the curvature of the ramp when easing out of the speed change. A value of 0 creates a sharp transition from the new speed to the original speed; a value of 100 creates the smoothest ease out. The default is 50%.
HUD Controls

The HUD contains the Speed, Ease In Time, Ease In Curve, Ease Out Time, and Ease Out Curve parameters.

Strobe

The Strobe behavior simulates the look of a strobe light or lower frame rate video by holding a number of frames as defined by the Strobe Duration parameter over the playback of the clip. For example, when Strobe Duration is set to 10, frame 1 is held for 10 frames, frame 11 for 10 frames, frame 21 for 10 frames, and so on. The frames in between (2–10, 12–20, 22–30, and so on) do not appear.

Parameters in the Inspector
  • Strobe Duration: A slider that sets the number of frames to hold. A value of 1 plays the clip at normal speed. The default value is 5 frames.
HUD Controls

The HUD contains the Strobe Duration parameter.

Stutter

This behavior randomly inserts hold frames, of random durations, into the playback of a clip. The effect is similar to a tape that sticks during play in a videocassette recorder.

Parameters in the Inspector
  • Stutter Amount: A slider that sets the probability that a hold frame is generated at the given frame. When set to 0%, no hold frames are created; when set to 100%, every frame is a hold frame. Values in between 0 and 100 indicate the probability of frames (within the duration of the behavior) that are replaced by hold frames. The default value is 10%.
  • Duration Range: A slider that sets the maximum duration of hold frames. A value of 1 inserts single-frame hold frames at a frequency determined by the Stutter Amount parameter. Increasing the Duration Range increases the range of hold frames. For example, a value of 30 creates random hold frames with a minimum of 1 frame and a maximum of 30 frames. The default value is 3 frames.
  • Random Seed: A button that lets you pick a new random seed number. This number is used to randomly generate new values, based on the other parameters of this behavior.
HUD Controls

The HUD contains the Stutter Amount, Duration Range, and Random Seed parameters.