1/* 2 * Copyright 2012 Sebastian Annies, Hamburg 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 */ 16package com.googlecode.mp4parser.authoring.builder; 17 18import java.nio.ByteBuffer; 19import java.nio.MappedByteBuffer; 20import java.util.ArrayList; 21import java.util.List; 22 23/** 24 * Used to merge adjacent byte buffers. 25 */ 26public class ByteBufferHelper { 27 public static List<ByteBuffer> mergeAdjacentBuffers(List<ByteBuffer> samples) { 28 ArrayList<ByteBuffer> nuSamples = new ArrayList<ByteBuffer>(samples.size()); 29 for (ByteBuffer buffer : samples) { 30 int lastIndex = nuSamples.size() - 1; 31 if (lastIndex >= 0 && buffer.hasArray() && nuSamples.get(lastIndex).hasArray() && buffer.array() == nuSamples.get(lastIndex).array() && 32 nuSamples.get(lastIndex).arrayOffset() + nuSamples.get(lastIndex).limit() == buffer.arrayOffset()) { 33 ByteBuffer oldBuffer = nuSamples.remove(lastIndex); 34 ByteBuffer nu = ByteBuffer.wrap(buffer.array(), oldBuffer.arrayOffset(), oldBuffer.limit() + buffer.limit()).slice(); 35 // We need to slice here since wrap([], offset, length) just sets position and not the arrayOffset. 36 nuSamples.add(nu); 37 } else if (lastIndex >= 0 && 38 buffer instanceof MappedByteBuffer && nuSamples.get(lastIndex) instanceof MappedByteBuffer && 39 nuSamples.get(lastIndex).limit() == nuSamples.get(lastIndex).capacity() - buffer.capacity()) { 40 // This can go wrong - but will it? 41 ByteBuffer oldBuffer = nuSamples.get(lastIndex); 42 oldBuffer.limit(buffer.limit() + oldBuffer.limit()); 43 } else { 44 buffer.rewind(); 45 nuSamples.add(buffer); 46 } 47 } 48 return nuSamples; 49 } 50} 51