Effect


public abstract class Effect
extends Object

java.lang.Object
   ↳ android.media.effect.Effect


Effects are high-performance transformations that can be applied to image frames. These are passed in the form of OpenGL ES 2.0 texture names. Typical frames could be images loaded from disk, or frames from the camera or other video streams.

To create an Effect you must first create an EffectContext. You can obtain an instance of the context's EffectFactory by calling getFactory(). The EffectFactory allows you to instantiate specific Effects.

The application is responsible for creating an EGL context, and making it current before applying an effect. An effect is bound to a single EffectContext, which in turn is bound to a single EGL context. If your EGL context is destroyed, the EffectContext becomes invalid and any effects bound to this context can no longer be used.

Summary

Public constructors

Effect()

Public methods

abstract void apply(int inputTexId, int width, int height, int outputTexId)

Apply an effect to GL textures.

abstract String getName()

Get the effect name.

abstract void release()

Release an effect.

abstract void setParameter(String parameterKey, Object value)

Set a filter parameter.

void setUpdateListener(EffectUpdateListener listener)

Set an effect listener.

Inherited methods

Public constructors

Effect

public Effect ()

Public methods

apply

Added in API level 14
public abstract void apply (int inputTexId, 
                int width, 
                int height, 
                int outputTexId)

Apply an effect to GL textures.

Apply the Effect on the specified input GL texture, and write the result into the output GL texture. The texture names passed must be valid in the current GL context.

The input texture must be a valid texture name with the given width and height and must be bound to a GL_TEXTURE_2D texture image (usually done by calling the glTexImage2D() function). Multiple mipmap levels may be provided.

If the output texture has not been bound to a texture image, it will be automatically bound by the effect as a GL_TEXTURE_2D. It will contain one mipmap level (0), which will have the same size as the input. No other mipmap levels are defined. If the output texture was bound already, and its size does not match the input texture size, the result may be clipped or only partially fill the texture.

Note, that regardless of whether a texture image was originally provided or not, both the input and output textures are owned by the caller. That is, the caller is responsible for calling glDeleteTextures() to deallocate the input and output textures.

Parameters
inputTexId int: The GL texture name of a valid and bound input texture.

width int: The width of the input texture in pixels.

height int: The height of the input texture in pixels.

outputTexId int: The GL texture name of the output texture.

getName

Added in API level 14
public abstract String getName ()

Get the effect name. Returns the unique name of the effect, which matches the name used for instantiating this effect by the EffectFactory.

Returns
String The name of the effect.

release

Added in API level 14
public abstract void release ()

Release an effect.

Releases the effect and any resources associated with it. You may call this if you need to make sure acquired resources are no longer held by the effect. Releasing an effect makes it invalid for reuse.

Note that this method must be called with the EffectContext and EGL context current, as the effect may release internal GL resources.

setParameter

Added in API level 14
public abstract void setParameter (String parameterKey, 
                Object value)

Set a filter parameter. Consult the effect documentation for a list of supported parameter keys for each effect.

Parameters
parameterKey String: The name of the parameter to adjust.

value Object: The new value to set the parameter to.

Throws
if parameterName is not a recognized name, or the value is not a valid value for this parameter.

setUpdateListener

Added in API level 14
public void setUpdateListener (EffectUpdateListener listener)

Set an effect listener. Some effects may report state changes back to the host, if a listener is set. Consult the individual effect documentation for more details.

Parameters
listener EffectUpdateListener: The listener to receive update callbacks on.