Timewarp

Use the Timewarp node to slow down, speed up, freeze, or reverse frames in a clip. Timewarps can have a constant or variable speed. In some cases, such as when creating a fit to fill edit on the timeline, a Timewarp is added automatically to a segment.

Settings

Settings for the Timewarp tool differ between Batch and the Timeline. The following documentation presents the controls for the Batch node and for the Timeline FX, as presented in the Effects environment. It is also possible to modify the Timewarp controls from the Timeline ribbon, in the Timeline tab.

The Timewarp settings in Batch

The Timewarp settings in the Effects environment

Timing Info

These settings are only available when you access the Timewarp Timeline FX editor, in the Effects environment. They are informational settings only, to give you information about the segment on the Timeline.

Source In

Displays the frame or timecode of the In point of the source segment.

Source Out

Displays the frame or timecode of the Out point of the source segment.

Timewarp In

Displays the frame or timecode of the In point of the Timewarp result.

Timewarp Out

Displays the frame or timecode of the Out point of the Timewarp result.

Record In

Displays the frame number or record timecode of the In point of the segment in the sequence.

Record Out

Displays the frame number or Record timecode of the Out point of the segment in the sequence.

Length

Displays the length of the segment.

Mode

The Mode controls in Batch

The Mode controls in the Effects environment

Timewarp Mode option

Select a Timewarp mode: Speed, Timing, or Duration (Duration is only available from timeline timewarp). Different settings appear depending on the mode selected. Timewarp modes are mutually exclusive, that is, animation settings are remembered for each mode.

Speed field

Sets the Timewarp speed.

Speed option

Select whether to display the speed as a percentage, or as frames per second.

Speed Timing field

Sets which frame from the source media is shown for the current frame, after the Timewarp is applied.

Reverse button

Click to create reverse timewarp effect; that is, change the speed field value to negative or positive. In Batch, use in conjunction with the Offset field to manually set the desired end of clip.

Timing field

Sets the source frame or timecode value for the current time. You can slip the source Media underneath a Timeline FX Timewarp, without affecting your keyframes, using the Timing field.

Duration field

Sets the duration of the segment in frames or timecode.

Duration Speed field

Sets the speed value corresponding to the duration set in the Duration field.

Strobe

Repeat field

Sets the number of frames or fields to be repeated to create a strobe effect. The strobe effect is applied after the Timewarp effect, so any speed or timing animations are respected when applying the strobe effect.

Anchoring

The Anchoring controls in Batch

Source field

Sets the anchor frame or timecode value of the Timewarp.

Offset field

Sets the amount of offset to apply to the anchor point.

The Anchoring controls in the Effects environment

Anchoring option

Select where to set the anchor frame so that its timing is not affected when modifying a timewarp.

Repeat Mode

This setting is only available for a Timewarp Timeline FX.

Repeat Mode box

Select how out of range timing values are handled.

Frame Interpolation

Frame Interpolation option

Select the frame interpolation used to blend timewarped frames. Different settings appear below depending on the mode selected.

Mode:	Description:
Mix	When mixing frames, you are combining multiple frames together to create one blended frame using an additive mix. Each result frame is a blend of an equal number of frames from both sides of the given frame.
Trails	With Trails blending, you have more control than in a simple mix. You can blend the frames before and after a given frame by different amounts. Do this to create a trail that comes before or after any motion in the clip. You can also set the amount of fall-off for the blend so that the trail fades away completely, partially, or not at all.
Motion	Motion estimation blends frames with subpixel accuracy, and is well-suited for particularly challenging timewarps. Motion estimation is good for processing slow-motion, constant, or variable speed timewarps of interlaced and progressive material. It is particularly good for material that introduces artefacts or for which you cannot get satisfactory results using Trail or Mix values.
Machine Learning	The inference uses two frames to generate an intermediate frame in-between them. Although any speed value can be set, some values require the creation of more intermediate frames to output the desired result, making the process slower. For example, a Timewarp set to 50% only requires the creation of one frame that is used as the result frame. A Timewarp set to 25% requires the creation of two frames: one used as an intermediate (50%) and a second one used as the result frame (25%). In some cases, up to 10 intermediates may be required to obtain the frame for the desired speed.

Note: For Machine Learning Frame interpolation, the playback and scrubbing of unrendered frames is now more interactive in the Timeline environment due to the Player option available in the Timeline FX Timewarp Preferences. By default, the option is set for scrubbing and playback to use the Mix frame interpolation at 0.0 instead of the Machine Learning Frame interpolation.

Sample option

Select whether the Timewarp samples the speed or timing curve at the start, in the middle, or at the end of a frame, like for a variable speed Timewarp.

Amount field

Sets the mix value for the Timewarp. Each result frame is a blend of an equal number of frames from both sides of the given frame.

Pre Amount field

Sets the value to mix the frames that precede the current frame with the current frame.

Pre Weight field

Sets the fall-off value for the pretrail. When the value is 0%, the image in the current frame is at 100% intensity and the first image in the trail is at 0% intensity. When the value is at 100%, there is no fall-off.

Post Amount field

Sets the value to mix the frames that follow the current frame with the current frame.

Post Weight field

Sets the fall-off value for the posttrail. When the value is 0%, the image in the current frame is at 100% intensity and the first image in the trail is at 0% intensity. When the value is at 100%, there is no fall-off. Editable.

Motion Analysis Quality option

Select the level of motion analysis accuracy and rendering speed. Select Use Full Resolution to render the images at the current resolution. In Batch or Batch FX, this setting is unavailable if an external input is attached to the node's forward vector or backward vector tabs.

Using the Full Resolution augments the analysis time, but provides higher quality results.

Motion Blur Active

Enable to apply a motion blur to the selected clip.

Samples field

Sets the number of frames to sample when creating the Timewarp. The samples include the current frame, and an equal distribution of past and future frames.

Shutter field

Sets the number of frames for which the shutter stays open. For example, when the shutter value is set to 3, every third frame is as a sample.

Reference Active

Enable to apply the Timewarp only to objects that do not have the same relative motion as the selected pixel. When enabled, you can edit values in the X and Y fields.

Reference Colour

Sets the colour of the crosshair that marks the reference point inside the Player / Viewport.

Reference X field

Sets the horizontal position of the pixel to use as a reference point at the selected frame.

Reference Y field

Sets the vertical position of the pixel to use as a reference point at the selected frame.

Rendering Platform option

Select whether the Machine Learning inference runs on the CPU or GPU.

On Rocky Linux, an inference can be run using either the CPU or GPU. On macOS, the inference is always run on the CPU. Running the inference is faster on the GPU, but larger frames that cannot be rendered using it can be rendered using the CPU.

ML Engine Cache

Enable to use NVIDIA's TensorRT cache.

This option is disabled by default as the generation of the tensorRT engine can take several minutes. Because the cache requires a new tensorRT engine for each combination of ML inference model, GPU, and image size, a new engine is generated each time a new model is applied on a new combination. Each engine is stored in a cache in /opt/Autodesk/cache/tensorgraph/models and is used the next time the same ML inference model, GPU, and image size combination is required, making it much faster to use the node.

Bit Depth option

Select whether the model is run in 16-bit fp or 32-bit fp on the GPU platform.

This option is only available on Rocky Linux.

Selecting 16-bit fp offers the following advantages:

1. It allows running a model on higher resolution images, since running in 16-bit fp requires less memory.
2. It provides better performance.
   
   
   
   

Rendering Mode

Rendering Mode option

Select the render mode between Progressive, Interlaced, or Automatic (using the scan format of the source).

Field Interpolation option

Select an interpolation mode (available if Interlaced or Automatic is selected as the rendering mode box). Interpolation helps remove field jitter artefacts that are produced when a reversal of fields occurs during the timewarp.

Start Frame

These settings are only available for a Timewarp Timeline FX.

Start Frame option

Select how to set the start frame of the timeline segment.

Custom Start Frame field

Sets the custom Start Frame value.

Use Segment Connections

Enable to apply the changes made to the Start Frame to all connected segments.