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.common.mylzw; 018 019import java.io.IOException; 020import java.io.InputStream; 021 022public class BitsToByteInputStream extends InputStream { 023 private final MyBitInputStream is; 024 private final int desiredDepth; 025 026 public BitsToByteInputStream(final MyBitInputStream is, final int desiredDepth) { 027 this.is = is; 028 this.desiredDepth = desiredDepth; 029 } 030 031 @Override 032 public int read() throws IOException { 033 return readBits(8); 034 } 035 036 public int readBits(final int bitCount) throws IOException { 037 int i = is.readBits(bitCount); 038 if (bitCount < desiredDepth) { 039 i <<= (desiredDepth - bitCount); 040 } else if (bitCount > desiredDepth) { 041 i >>= (bitCount - desiredDepth); 042 } 043 044 return i; 045 } 046 047 public int[] readBitsArray(final int sampleBits, final int length) throws IOException { 048 final int[] result = new int[length]; 049 050 for (int i = 0; i < length; i++) { 051 result[i] = readBits(sampleBits); 052 } 053 054 return result; 055 } 056}