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1 /** |
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2 * Java RTP Library (jlibrtp) |
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3 * Copyright (C) 2006 Arne Kepp |
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4 * |
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5 * This library is free software; you can redistribute it and/or |
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6 * modify it under the terms of the GNU Lesser General Public |
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7 * License as published by the Free Software Foundation; either |
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8 * version 2.1 of the License, or (at your option) any later version. |
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9 * |
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10 * This library is distributed in the hope that it will be useful, |
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11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 * Lesser General Public License for more details. |
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14 * |
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15 * You should have received a copy of the GNU Lesser General Public |
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16 * License along with this library; if not, write to the Free Software |
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17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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18 */ |
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19 package jlibrtp; |
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20 |
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21 /** |
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22 * Generic functions for converting between unsigned integers and byte[]s. |
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23 * |
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24 * @author Arne Kepp |
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25 */ |
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26 public class StaticProcs { |
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27 |
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28 /** |
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29 * Converts an integer into an array of bytes. |
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30 * Primarily used for 16 bit unsigned integers, ignore the first two octets. |
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31 * |
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32 * @param i a 16 bit unsigned integer in an int |
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33 * @return byte[2] representing the integer as unsigned, most significant bit first. |
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34 */ |
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35 public static byte[] uIntIntToByteWord(int i) { |
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36 byte[] byteWord = new byte[2]; |
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37 byteWord[0] = (byte) ((i >> 8) & 0x000000FF); |
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38 byteWord[1] = (byte) (i & 0x00FF); |
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39 return byteWord; |
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40 } |
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41 |
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42 /** |
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43 * Converts an unsigned 32 bit integer, stored in a long, into an array of bytes. |
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44 * |
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45 * @param j a long |
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46 * @return byte[4] representing the unsigned integer, most significant bit first. |
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47 */ |
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48 public static byte[] uIntLongToByteWord(long j) { |
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49 int i = (int) j; |
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50 byte[] byteWord = new byte[4]; |
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51 byteWord[0] = (byte) ((i >>> 24) & 0x000000FF); |
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52 byteWord[1] = (byte) ((i >> 16) & 0x000000FF); |
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53 byteWord[2] = (byte) ((i >> 8) & 0x000000FF); |
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54 byteWord[3] = (byte) (i & 0x00FF); |
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55 return byteWord; |
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56 } |
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57 |
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58 /** |
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59 * Combines two bytes (most significant bit first) into a 16 bit unsigned integer. |
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60 * |
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61 * @param index of most significant byte |
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62 * @return int with the 16 bit unsigned integer |
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63 */ |
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64 public static int bytesToUIntInt(byte[] bytes, int index) { |
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65 int accum = 0; |
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66 int i = 1; |
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67 for (int shiftBy = 0; shiftBy < 16; shiftBy += 8 ) { |
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68 accum |= ( (long)( bytes[index + i] & 0xff ) ) << shiftBy; |
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69 i--; |
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70 } |
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71 return accum; |
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72 } |
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73 |
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74 /** |
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75 * Combines four bytes (most significant bit first) into a 32 bit unsigned integer. |
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76 * |
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77 * @param bytes |
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78 * @param index of most significant byte |
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79 * @return long with the 32 bit unsigned integer |
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80 */ |
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81 public static long bytesToUIntLong(byte[] bytes, int index) { |
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82 long accum = 0; |
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83 int i = 3; |
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84 for (int shiftBy = 0; shiftBy < 32; shiftBy += 8 ) { |
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85 accum |= ( (long)( bytes[index + i] & 0xff ) ) << shiftBy; |
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86 i--; |
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87 } |
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88 return accum; |
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89 } |
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90 |
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91 /** |
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92 * Converts an arbitrary number of bytes, assumed to represent an unsigned integer, |
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93 * to a Java long |
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94 */ |
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95 /*public static long bytesToUintLong(byte[] bytes, int firstByte, int lastByte) { |
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96 long accum = 0; |
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97 int i = lastByte - firstByte; |
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98 if(i > 7) { |
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99 System.out.println("!!!! StaticProcs.bytesToUintLong() Can't convert more than 63 bits!"); |
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100 return -1; |
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101 } |
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102 int stop = (i+1)*8; |
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103 |
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104 for (int shiftBy = 0; shiftBy < stop; shiftBy += 8 ) { |
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105 accum |= ( (long)( bytes[firstByte + i] & 0xff ) ) << shiftBy; |
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106 i--; |
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107 } |
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108 return accum; |
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109 }*/ |
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110 |
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111 /** |
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112 * Converts an arbitrary number of bytes, assumed to represent an unsigned integer, |
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113 * to a Java int |
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114 */ |
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115 /* public static int bytesToUintInt(byte[] bytes, int firstByte, int lastByte) { |
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116 int accum = 0; |
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117 int i = lastByte - firstByte; |
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118 if(i > 3) { |
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119 System.out.println("!!!! StaticProcs.bytesToUintLong() Can't convert more than 31 bits!"); |
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120 return -1; |
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121 } |
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122 int stop = (i+1)*8; |
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123 |
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124 for (int shiftBy = 0; shiftBy < stop; shiftBy += 8 ) { |
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125 accum |= ( (long)( bytes[firstByte + i] & 0xff ) ) << shiftBy; |
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126 i--; |
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127 } |
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128 return accum; |
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129 }*/ |
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130 |
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131 /** |
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132 * Recreates a UNIX timestamp based on the NTP representation used |
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133 * in RTCP SR packets |
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134 * |
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135 * @param ntpTs1 from RTCP SR packet |
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136 * @param ntpTs2 from RTCP SR packet |
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137 * @return the UNIX timestamp |
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138 */ |
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139 public static long undoNtpMess(long ntpTs1, long ntpTs2) { |
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140 long timeVal = (ntpTs1 - 2208988800L)*1000; |
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141 |
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142 double tmp = (1000.0*(double)ntpTs2)/((double)4294967295L); |
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143 long ms = (long) tmp; |
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144 //System.out.println(" timeVal: " +Long.toString(timeVal)+ " ms " + Long.toString(ms)); |
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145 timeVal += ms; |
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146 |
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147 return timeVal; |
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148 } |
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149 |
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150 |
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151 |
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152 /** |
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153 * Get the bits of a byte |
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154 * |
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155 * @param aByte the byte you wish to convert |
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156 * @return a String of 1's and 0's |
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157 */ |
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158 public static String bitsOfByte(byte aByte) { |
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159 int temp; |
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160 String out = ""; |
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161 for(int i=7; i>=0; i--) { |
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162 temp = (aByte >>> i); |
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163 temp &= 0x0001; |
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164 out += (""+temp); |
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165 } |
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166 return out; |
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167 } |
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168 |
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169 /** |
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170 * Get the hex representation of a byte |
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171 * |
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172 * @param aByte the byte you wish to convert |
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173 * @return a String of two chars 0-1,A-F |
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174 */ |
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175 public static String hexOfByte(byte aByte) { |
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176 String out = ""; |
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177 |
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178 for(int i=0; i<2; i++) { |
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179 int temp = (int) aByte; |
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180 if(temp < 0) { |
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181 temp +=256; |
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182 } |
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183 if(i == 0) { |
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184 temp = temp/16; |
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185 } else { |
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186 temp = temp%16; |
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187 } |
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188 |
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189 if( temp > 9) { |
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190 switch(temp) { |
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191 case 10: out += "A"; break; |
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192 case 11: out += "B"; break; |
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193 case 12: out += "C"; break; |
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194 case 13: out += "D"; break; |
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195 case 14: out += "E"; break; |
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196 case 15: out += "F"; break; |
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197 } |
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198 } else { |
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199 out += Integer.toString(temp); |
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200 } |
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201 } |
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202 return out; |
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203 } |
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204 |
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205 /** |
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206 * Get the hex representation of a byte |
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207 * |
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208 * @param hex 4 bytes the byte you wish to convert |
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209 * @return a String of two chars 0-1,A-F |
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210 */ |
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211 public static byte byteOfHex(byte[] hex) { |
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212 byte retByte = 0; |
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213 Byte tmp; |
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214 int val = 0; |
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215 |
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216 // First 4 bits |
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217 tmp = hex[0]; |
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218 val = tmp.intValue(); |
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219 if(val > 64) { |
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220 // Letter |
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221 val -= 55; |
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222 } else { |
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223 // Number |
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224 val -= 48; |
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225 } |
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226 retByte = ((byte) (val << 4)); |
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227 |
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228 // Last 4 bits |
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229 tmp = hex[1]; |
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230 val = tmp.intValue(); |
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231 if(val > 64) { |
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232 // Letter |
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233 val -= 55; |
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234 } else { |
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235 // Number |
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236 val -= 48; |
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237 } |
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238 retByte |= ((byte) val); |
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239 |
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240 return retByte; |
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241 } |
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242 |
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243 |
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244 /** |
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245 * Print the bits of a byte to standard out. For debugging. |
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246 * |
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247 * @param aByte the byte you wish to print out. |
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248 */ |
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249 public static void printBits(byte aByte) { |
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250 int temp; |
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251 for(int i=7; i>=0; i--) { |
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252 temp = (aByte >>> i); |
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253 temp &= 0x0001; |
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254 System.out.print(""+temp); |
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255 } |
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256 System.out.println(); |
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257 } |
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258 |
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259 public static String bitsOfBytes(byte[] bytes) { |
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260 String str = ""; |
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261 //Expensive, but who cares |
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262 for(int i=0; i<bytes.length; i++ ) { |
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263 str += bitsOfByte(bytes[i]) + " "; |
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264 if((i + 1) % 4 == 0) |
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265 str += "\n"; |
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266 } |
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267 |
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268 return str; |
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269 } |
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270 } |