| <HTML> |
| <BODY> |
| <p>Provides classes that allow you to apply a variety of visual effects to images and |
| videos. For example, you can easily fix red-eye, convert an image to grayscale, |
| adjust brightness, adjust saturation, rotate an image, apply a fisheye effect, and much more. The |
| system performs all effects processing on the GPU to obtain maximum performance.</p> |
| |
| <p>For maximum performance, effects are applied directly to OpenGL textures, so your application |
| must have a valid OpenGL context before it can use the effects APIs. The textures to which you apply |
| effects may be from bitmaps, videos or even the camera. However, there are certain restrictions that |
| textures must meet:</p> |
| <ol> |
| <li>They must be bound to a {@link android.opengl.GLES20#GL_TEXTURE_2D} texture image</li> |
| <li>They must contain at least one mipmap level</li> |
| </ol> |
| |
| <p>An {@link android.media.effect.Effect} object defines a single media effect that you can apply to |
| an image frame. The basic workflow to create an {@link android.media.effect.Effect} is:</p> |
| |
| <ol> |
| <li>Call {@link android.media.effect.EffectContext#createWithCurrentGlContext |
| EffectContext.createWithCurrentGlContext()} from your OpenGL ES 2.0 context.</li> |
| <li>Use the returned {@link android.media.effect.EffectContext} to call {@link |
| android.media.effect.EffectContext#getFactory EffectContext.getFactory()}, which returns an instance |
| of {@link android.media.effect.EffectFactory}.</li> |
| <li>Call {@link android.media.effect.EffectFactory#createEffect createEffect()}, passing it an |
| effect name from {@link android.media.effect.EffectFactory}, such as {@link |
| android.media.effect.EffectFactory#EFFECT_FISHEYE} or {@link |
| android.media.effect.EffectFactory#EFFECT_VIGNETTE}.</li> |
| </ol> |
| |
| <p>You can adjust an effect’s parameters by calling {@link android.media.effect.Effect#setParameter |
| setParameter()} and passing a parameter name and parameter value. Each type of effect accepts |
| different parameters, which are documented with the effect name. For example, {@link |
| android.media.effect.EffectFactory#EFFECT_FISHEYE} has one parameter for the {@code scale} of the |
| distortion.</p> |
| |
| <p>To apply an effect on a texture, call {@link android.media.effect.Effect#apply apply()} on the |
| {@link |
| android.media.effect.Effect} and pass in the input texture, its width and height, and the output |
| texture. The input texture must be bound to a {@link android.opengl.GLES20#GL_TEXTURE_2D} texture |
| image (usually done by calling the {@link android.opengl.GLES20#glTexImage2D glTexImage2D()} |
| function). You may provide multiple mipmap levels. If the output texture has not been bound to a |
| texture image, it will be automatically bound by the effect as a {@link |
| android.opengl.GLES20#GL_TEXTURE_2D} and with one mipmap level (0), which will have the same |
| size as the input.</p> |
| |
| <p class="note"><strong>Note:</strong> All effects listed in {@link |
| android.media.effect.EffectFactory} are guaranteed to be supported. However, some additional effects |
| available from external libraries are not supported by all devices, so you must first check if the |
| desired effect from the external library is supported by calling {@link |
| android.media.effect.EffectFactory#isEffectSupported isEffectSupported()}.</p> |
| </BODY> |
| </HTML> |
