SurfaceOutput.java
/*
* Copyright 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.camera.core;
import android.graphics.SurfaceTexture;
import android.util.Size;
import android.view.Surface;
import androidx.annotation.NonNull;
import androidx.annotation.RestrictTo;
import com.google.common.util.concurrent.ListenableFuture;
import java.util.concurrent.Executor;
/**
* A completable, single-use {@link Surface} for outputting processed camera frames.
*
* <p>Contains a {@link ListenableFuture<Surface>} and its characteristics along with methods
* for notifying the end of life of the {@link Surface} and marking the {@link Surface} as no
* longer in use.
*
* @hide
* @see SurfaceEffect#onOutputSurface(SurfaceOutput)
*/
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
public interface SurfaceOutput {
/**
* Gets the output {@link Surface} for writing processed frames.
*
* <p> If there are multiple calls to the method, only the {@link OnCloseRequestedListener}
* from the last call will be triggered.
*
* @param executor on which the listener should be invoked.
* @param listener a listener to notify the implementation about the end-of-life of the
* {@link SurfaceOutput}. The implementation should then invoke
* {@link #close()} to mark the {@link Surface} as no longer in use.
* @see OnCloseRequestedListener
*/
@NonNull
Surface getSurface(
@NonNull Executor executor,
@NonNull OnCloseRequestedListener listener);
/**
* This field indicates that what purpose the {@link Surface} will be used for.
*
* <ul>
* <li>{@link SurfaceEffect#PREVIEW} if the {@link Surface} will be used for {@link Preview}.
* <li>{@link SurfaceEffect#VIDEO_CAPTURE} if the {@link Surface} will be used for video
* capture.
* <li>{@link SurfaceEffect#PREVIEW} | {@link SurfaceEffect#VIDEO_CAPTURE} if the output
* {@link Surface} will be used for sharing a single stream for both preview and video capture.
* </ul>
*/
@CameraEffect.Targets
int getTargets();
/**
* Gets the size of the {@link Surface}.
*/
@NonNull
Size getSize();
/**
* Gets the format of the {@link Surface}.
*/
int getFormat();
/**
* Call this method to mark the {@link Surface} provided via {@link #getSurface} as no longer in
* use.
*
* <p>After this is called, the implementation should stop writing to the {@link Surface}.
*/
void close();
/**
* Updates the 4 x 4 transformation matrix retrieved from {@link SurfaceTexture
* #getTransformMatrix}.
*
* <p>This method applies an additional transformation on top of the value of
* {@link SurfaceTexture#getTransformMatrix}. The result is matrix of the same format, which
* is a transform matrix maps 2D homogeneous texture coordinates of the form (s, t, 0, 1)
* with s and t in the inclusive range [0, 1] to the texture coordinate that should be used
* to sample that location from the texture. The result should be used in the same way as
* the original matrix. Please see the Javadoc of {@link SurfaceTexture#getTransformMatrix}.
*
* <p>The additional transformation is calculated based on the target rotation, target
* resolution and the {@link ViewPort} configured by the app. The value could also include
* workaround for device specific quirks.
*
* @param updated the array into which the 4x4 matrix will be stored. The array must
* have exactly 16 elements.
* @param original the original value retrieved from
* {@link SurfaceTexture#getTransformMatrix}. The array must have exactly 16
* elements.
* @see SurfaceTexture#getTransformMatrix(float[])
*/
void updateTransformMatrix(@NonNull float[] updated, @NonNull float[] original);
/**
* A listener to notify the implementation about the end-of-life of the {@link Surface}.
*/
interface OnCloseRequestedListener {
/**
* After this is invoked, the implementation should finish the current access to the
* {@link Surface}, stop writing to the {@link Surface} and mark the
* {@link SurfaceOutput} as closed by calling {@link SurfaceOutput#close()}.
*/
void onCloseRequested();
}
}