001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.imaging.formats.webp.chunks; 018 019import java.io.IOException; 020import java.io.PrintWriter; 021import java.nio.ByteOrder; 022import java.nio.charset.StandardCharsets; 023 024import org.apache.commons.imaging.ImagingException; 025import org.apache.commons.imaging.common.BinaryFileParser; 026import org.apache.commons.imaging.internal.SafeOperations; 027 028/** 029 * A WebP image is composed of several chunks. This is the base class for the chunks, used by the parser. 030 * 031 * @see <a href="https://developers.google.com/speed/webp/docs/riff_container">WebP Container Specification</a> 032 * @since 1.0-alpha4 033 */ 034public abstract class WebPChunk extends BinaryFileParser { 035 private final int type; 036 private final int size; 037 protected final byte[] bytes; 038 private final int chunkSize; 039 040 /** 041 * Create a new WebP chunk. 042 * 043 * @param type chunk type. 044 * @param size chunk size. 045 * @param bytes chunk data. 046 * @throws ImagingException if the chunk data and the size provided do not match. 047 */ 048 WebPChunk(final int type, final int size, final byte[] bytes) throws ImagingException { 049 super(ByteOrder.LITTLE_ENDIAN); 050 051 if (size != bytes.length) { 052 throw new ImagingException("Chunk size must match bytes length"); 053 } 054 055 this.type = type; 056 this.size = size; 057 this.bytes = bytes; 058 059 // if chunk size is odd, a single padding byte is added 060 final int padding = size % 2 != 0 ? 1 : 0; 061 062 // Chunk FourCC (4 bytes) + Chunk Size (4 bytes) + Chunk Payload (n bytes) + Padding 063 this.chunkSize = SafeOperations.add(4, 4, size, padding); 064 } 065 066 /** 067 * Print the chunk to the given stream. 068 * 069 * @param pw a stream to write to. 070 * @param offset chunk offset. 071 * @throws ImagingException if the image is invalid. 072 * @throws IOException if it fails to write to the given stream. 073 */ 074 public void dump(final PrintWriter pw, final int offset) throws ImagingException, IOException { 075 pw.printf("Chunk %s at offset %s, length %d%n, payload size %d%n", getTypeDescription(), offset >= 0 ? String.valueOf(offset) : "unknown", 076 getChunkSize(), getPayloadSize()); 077 } 078 079 /** 080 * @return a copy of the chunk data as bytes. 081 */ 082 public byte[] getBytes() { 083 return bytes.clone(); 084 } 085 086 /** 087 * @return the chunk size. 088 */ 089 public int getChunkSize() { 090 return chunkSize; 091 } 092 093 /** 094 * @return the payload size. 095 */ 096 public int getPayloadSize() { 097 return size; 098 } 099 100 /** 101 * @return the chunk type. 102 */ 103 public int getType() { 104 return type; 105 } 106 107 /** 108 * @return the description of the chunk type. 109 */ 110 public String getTypeDescription() { 111 return new String(new byte[] { (byte) (type & 0xff), (byte) (type >> 8 & 0xff), (byte) (type >> 16 & 0xff), (byte) (type >> 24 & 0xff) }, 112 StandardCharsets.UTF_8); 113 } 114}