Contrast

Kotlin |Java

@UnstableApi
public final class Contrast implements RgbMatrix

A RgbMatrix to control the contrast of video frames.

Summary

Public constructors
`Contrast(@FloatRange(from = "-1", to = 1) float contrast)` Creates a new instance for the given contrast value.

Public methods
`float[]`	`getMatrix(long presentationTimeUs, boolean useHdr)` Returns the 4x4 RGB transformation `matrix` to apply to the color values of each pixel in the frame with the given timestamp.
`boolean`	`isNoOp(int inputWidth, int inputHeight)` Returns whether a `GlEffect` applies no change at every timestamp.

long

getDurationAfterEffectApplied(long durationUs)

Returns the expected duration of the output stream when the effect is applied given a input durationUs.

abstract GlShaderProgram

toGlShaderProgram(Context context, boolean useHdr)

Returns a GlShaderProgram that applies the effect.

BaseGlShaderProgram

toGlShaderProgram(Context context, boolean useHdr)

Returns a GlShaderProgram that applies the effect.

public Contrast(@FloatRange(from = "-1", to = 1) float contrast)

Creates a new instance for the given contrast value.

Contrast values range from -1 (all gray pixels) to 1 (maximum difference of colors). 0 means to add no contrast and leaves the frames unchanged.

public float[] getMatrix(long presentationTimeUs, boolean useHdr)

Returns the 4x4 RGB transformation matrix to apply to the color values of each pixel in the frame with the given timestamp.

Parameters
`long presentationTimeUs`	The timestamp of the frame to apply the matrix on.
`boolean useHdr`	If `true`, colors will be in linear RGB BT.2020. If `false`, colors will be in linear RGB BT.709. Must be consistent with `useHdr` in `toGlShaderProgram`.

Returns
`float[]`	The `RgbMatrix` to apply to the frame.

public boolean isNoOp(int inputWidth, int inputHeight)

Returns whether a GlEffect applies no change at every timestamp.

This can be used as a hint to skip this instance.

Parameters
`int inputWidth`	The input frame width, in pixels.
`int inputHeight`	The input frame height, in pixels.