1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.camera.burst; 18 19 import android.hardware.camera2.TotalCaptureResult; 20 21 /** 22 * The eviction strategy of the internal Camera image buffer. 23 * <p/> 24 * For a burst the Camera maintains an internal image buffer. This image buffer 25 * has limited memory and old images need to be evicted for storing new images. 26 * The eviction handler encapsulates the eviction strategy that the Camera uses 27 * to evict frames. 28 */ 29 public interface EvictionHandler { 30 /** 31 * Return the timestamp of the image that should be dropped. 32 * <p/> 33 * This method is called when the internal image buffer is out of capacity 34 * and needs to drop an image from the buffer. 35 * <p/> 36 * This should return one of the timestamps passed into 37 * {@link #onFrameInserted(long)}, and which has not yet 38 * been dropped. 39 * 40 * @return the timestamp of the frame to drop. 41 */ 42 long selectFrameToDrop(); 43 44 /** 45 * Called when the capture result for a frame is available. 46 * 47 * @param timestamp the timestamp of the frame, this frame may or may not be 48 * present in the image buffer. 49 * @param captureResult the capture result of the image. 50 */ 51 void onFrameCaptureResultAvailable(long timestamp, 52 TotalCaptureResult captureResult); 53 54 /** 55 * Called when an image is inserted in the image buffer. 56 * 57 * @param timestamp the timestamp of the inserted frame in the image buffer. 58 */ 59 void onFrameInserted(long timestamp); 60 61 /** 62 * Called when a frame is dropped from the image buffer. 63 * 64 * @param timestamp the timestamp of the dropped frame. 65 */ 66 void onFrameDropped(long timestamp); 67 } 68