/*
* Copyright 2013 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.media.filterfw;
import java.nio.ByteBuffer;
/**
* A collection of utilities to deal with pixel operations on ByteBuffers.
*/
public class PixelUtils {
/**
* Copy pixels from one buffer to another, applying a transformation.
*
* <p>The transformation is specified by specifying the initial offset in the output buffer, the
* stride (in pixels) between each pixel, and the stride (in pixels) between each row. The row
* stride is measured as the number of pixels between the start of each row.</p>
*
* <p>Note that this method is native for efficiency reasons. It does NOT do any bounds checking
* other than making sure the buffers are of sufficient size. This means that you can corrupt
* memory if specifying incorrect stride values!</p>
*
* @param input The input buffer containing pixel data.
* @param output The output buffer to hold the transformed pixel data.
* @param width The width of the input image.
* @param height The height of the input image.
* @param offset The start offset in the output (in pixels)
* @param pixStride The stride between each pixel (in pixels)
* @param rowStride The stride between the start of each row (in pixels)
*/
public static void copyPixels(ByteBuffer input,
ByteBuffer output,
int width,
int height,
int offset,
int pixStride,
int rowStride) {
if (input.remaining() != output.remaining()) {
throw new IllegalArgumentException("Input and output buffers must have the same size!");
} else if (input.remaining() % 4 != 0) {
throw new IllegalArgumentException("Input buffer size must be a multiple of 4!");
} else if (output.remaining() % 4 != 0) {
throw new IllegalArgumentException("Output buffer size must be a multiple of 4!");
} else if ((width * height * 4) != input.remaining()) {
throw new IllegalArgumentException(
"Input buffer size does not match given dimensions!");
} else if ((width * height * 4) != output.remaining()) {
throw new IllegalArgumentException(
"Output buffer size does not match given dimensions!");
}
nativeCopyPixels(input, output, width, height, offset, pixStride, rowStride);
}
private static native void nativeCopyPixels(ByteBuffer input,
ByteBuffer output,
int width,
int height,
int offset,
int pixStride,
int rowStride);
static {
System.loadLibrary("smartcamera_jni");
}
}