1 /* 2 * Copyright 2013 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 package androidx.media.filterfw; 17 18 import java.nio.ByteBuffer; 19 20 /** 21 * A collection of utilities to deal with pixel operations on ByteBuffers. 22 */ 23 public class PixelUtils { 24 25 /** 26 * Copy pixels from one buffer to another, applying a transformation. 27 * 28 * <p>The transformation is specified by specifying the initial offset in the output buffer, the 29 * stride (in pixels) between each pixel, and the stride (in pixels) between each row. The row 30 * stride is measured as the number of pixels between the start of each row.</p> 31 * 32 * <p>Note that this method is native for efficiency reasons. It does NOT do any bounds checking 33 * other than making sure the buffers are of sufficient size. This means that you can corrupt 34 * memory if specifying incorrect stride values!</p> 35 * 36 * @param input The input buffer containing pixel data. 37 * @param output The output buffer to hold the transformed pixel data. 38 * @param width The width of the input image. 39 * @param height The height of the input image. 40 * @param offset The start offset in the output (in pixels) 41 * @param pixStride The stride between each pixel (in pixels) 42 * @param rowStride The stride between the start of each row (in pixels) 43 */ 44 public static void copyPixels(ByteBuffer input, 45 ByteBuffer output, 46 int width, 47 int height, 48 int offset, 49 int pixStride, 50 int rowStride) { 51 if (input.remaining() != output.remaining()) { 52 throw new IllegalArgumentException("Input and output buffers must have the same size!"); 53 } else if (input.remaining() % 4 != 0) { 54 throw new IllegalArgumentException("Input buffer size must be a multiple of 4!"); 55 } else if (output.remaining() % 4 != 0) { 56 throw new IllegalArgumentException("Output buffer size must be a multiple of 4!"); 57 } else if ((width * height * 4) != input.remaining()) { 58 throw new IllegalArgumentException( 59 "Input buffer size does not match given dimensions!"); 60 } else if ((width * height * 4) != output.remaining()) { 61 throw new IllegalArgumentException( 62 "Output buffer size does not match given dimensions!"); 63 } 64 nativeCopyPixels(input, output, width, height, offset, pixStride, rowStride); 65 } 66 67 private static native void nativeCopyPixels(ByteBuffer input, 68 ByteBuffer output, 69 int width, 70 int height, 71 int offset, 72 int pixStride, 73 int rowStride); 74 75 static { 76 System.loadLibrary("smartcamera_jni"); 77 } 78 79 } 80
