Feedback In the S_Feedback Plugin. The previous frames of the input clip are transformed and combined with the current frame to give a variety of effects inspired by video feedback. The output of each processed frame is stored and then combined with the next frame. The feedback is reinitialized whenever any non-consecutive frame is processed: either the first frame, reprocessing a given frame, or jumping to another frame. You must process multiple frames of a clip in a row to observe the effect. Inputs: Source:  The clip to be processed.

Parameters:

Fade:   Default: 0.8,  Range: 0 or greater,  Shared.
For each frame, the previous output is scaled by this amount before it is combined with the new input frame. Normally this value should be less than 1.0 which causes previous frames to fade out over time. A value of 1.0 causes no fading, and values greater than 1.0 cause previous frames to become brighter over time.

Brightness:   Default: 1,  Range: 0 or greater,  Shared.
Scales the brightness of all frames.

Blur Amount:   Default: 0,  Range: 0 or greater.
The previous frames are blurred by this amount for each new frame. This has no effect unless it is positive.

Diffuse Amount:   Default: 0,  Range: 0 or greater.
The previous frames are passed through a pixel-diffusion process of this magnitude, for each new frame. This has no effect unless it is positive.

Amount Rel:   X & Y,   Default: [1 1],  Range: 0 or greater.
The relative amounts of horizontal and vertical blurring and/or diffusing. This has no effect unless Blur Amount or Diffuse Amount are positive.

Combine:   Popup menu,  Default: Ave.
Selects the method for combining previous frames with the current frame.

Ave:  The current frame is averaged with the previous output, smearing moving objects out over time. The output is scaled by Fade and the input is scaled by 1.0-Fade for a weighted average, so Fade must be less than 1.0 for this to work properly. Unlike the other combine options, Ave should never affect the brightness of stationary objects in the clip.

Max:  The colors of the current frame and previous frames are combined with a maximum function. This makes the output frame at least as bright as the current frame, and will make brighter 'trails' for example if you have bright objects moving on a dark background.

Screen:  The colors of the current frame and previous frames are combined with a blend function. This can be used to accumulate the colors of a moving clip. However, non-black regions will become brighter with each frame.

Add:  The colors of the current frame and previous frames are added. This can also be used to accumulate the colors of a moving clip, with the non-black regions becoming brighter at each frame.

Min:  The colors of the current frame and previous frames are combined with a minimum function. This makes the output frame no brighter than the current frame, and will often fade quickly to a black frame.

Fade Color:   Default rgb: [1 1 1],  Shared.
For each frame, the previous output is scaled by this color before it is combined with the new input frame. This is similar to Fade but affects the colors of the previous frames instead of just the brightness.

Color:   Default rgb: [1 1 1],  Shared.
Scales the color of all frames. Set this color to the complement of Fade Color to offset overly colored trails.

Center:   X & Y,   Default: [0 0],  Range: any.
The center position for rotation and scaling, in screen coordinates relative to the center of the frame. This parameter can be adjusted using the Center Widget.

Z Dist:   Default: 0.95,  Range: 0.001 or greater.
For each new frame, the 'distance' of the previous frames is scaled by this amount. This causes zooming during the feedback process. Values greater than 1.0 zoom out and make the previous frames smaller, and values less then 1.0 zoom in and enlarge them. This parameter can be adjusted using the Transform Widget.

Rotate:   Default: 3,  Range: any.
For each new frame, the amount of rotation in degrees to apply to the previous frames. This parameter can be adjusted using the Transform Widget.

Hue Shift:   Default: 0,  Range: any,  Shared.
Shifts the hue of the previous frames' colors, for each new frame.

Shift:   X & Y,   Default: [0 0],  Range: any.
Shifts the previous frames by this amount for each new frame. If this is non-zero the Center location is less meaningful. This parameter can be adjusted using the Shift Widget.

Wrap:   X & Y,  Popup menu,  Default: [NO NO].
Determines the method for accessing outside the borders of the source image.

NO:  gives black beyond the borders.

TILE:  repeats a copy of the image.

REFLECT:  repeats a mirrored copy. Edges are often less visible with this method.

See Also:

Trails TrailsDiffuse FeedbackDistort TimeAverage NearestColor FeedbackBubble

FeedbackMatte

WarpRepeat WarpChroma

Sapphire Plug-ins Introduction

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