ImageProcessor.java

/*
 * Copyright 2021 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.extensions.internal.sessionprocessor;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;

/**
 * An interface to receive and process the upcoming next available Image.
 */
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
public interface ImageProcessor {
    /**
     * The reference count will be decremented when this method returns. If an extension wants
     * to hold onto the image, it should increment the reference count in this method and
     * decrement it when the image is no longer needed.
     *
     * <p>If OEM is not closing(decrement) the image fast enough, the imageReference passed
     * in this method might contain null image meaning that the Image was closed to prevent
     * preview from stalling.
     */
    void onNextImageAvailable(
            int outputStreamId,
            long timestampNs,
            @NonNull ImageReference imageReference,
            @Nullable String physicalCameraId);
}