/**
* Java RTP Library (jlibrtp)
* Copyright (C) 2006 Arne Kepp
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package jlibrtp;
/**
* Generic functions for converting between unsigned integers and byte[]s.
*
* @author Arne Kepp
*/
public class StaticProcs {
/**
* Converts an integer into an array of bytes.
* Primarily used for 16 bit unsigned integers, ignore the first two octets.
*
* @param i a 16 bit unsigned integer in an int
* @return byte[2] representing the integer as unsigned, most significant bit first.
*/
public static byte[] uIntIntToByteWord(int i) {
byte[] byteWord = new byte[2];
byteWord[0] = (byte) ((i >> 8) & 0x000000FF);
byteWord[1] = (byte) (i & 0x00FF);
return byteWord;
}
/**
* Converts an unsigned 32 bit integer, stored in a long, into an array of bytes.
*
* @param j a long
* @return byte[4] representing the unsigned integer, most significant bit first.
*/
public static byte[] uIntLongToByteWord(long j) {
int i = (int) j;
byte[] byteWord = new byte[4];
byteWord[0] = (byte) ((i >>> 24) & 0x000000FF);
byteWord[1] = (byte) ((i >> 16) & 0x000000FF);
byteWord[2] = (byte) ((i >> 8) & 0x000000FF);
byteWord[3] = (byte) (i & 0x00FF);
return byteWord;
}
/**
* Combines two bytes (most significant bit first) into a 16 bit unsigned integer.
*
* @param index of most significant byte
* @return int with the 16 bit unsigned integer
*/
public static int bytesToUIntInt(byte[] bytes, int index) {
int accum = 0;
int i = 1;
for (int shiftBy = 0; shiftBy < 16; shiftBy += 8 ) {
accum |= ( (long)( bytes[index + i] & 0xff ) ) << shiftBy;
i--;
}
return accum;
}
/**
* Combines four bytes (most significant bit first) into a 32 bit unsigned integer.
*
* @param bytes
* @param index of most significant byte
* @return long with the 32 bit unsigned integer
*/
public static long bytesToUIntLong(byte[] bytes, int index) {
long accum = 0;
int i = 3;
for (int shiftBy = 0; shiftBy < 32; shiftBy += 8 ) {
accum |= ( (long)( bytes[index + i] & 0xff ) ) << shiftBy;
i--;
}
return accum;
}
/**
* Converts an arbitrary number of bytes, assumed to represent an unsigned integer,
* to a Java long
*/
/*public static long bytesToUintLong(byte[] bytes, int firstByte, int lastByte) {
long accum = 0;
int i = lastByte - firstByte;
if(i > 7) {
System.out.println("!!!! StaticProcs.bytesToUintLong() Can't convert more than 63 bits!");
return -1;
}
int stop = (i+1)*8;
for (int shiftBy = 0; shiftBy < stop; shiftBy += 8 ) {
accum |= ( (long)( bytes[firstByte + i] & 0xff ) ) << shiftBy;
i--;
}
return accum;
}*/
/**
* Converts an arbitrary number of bytes, assumed to represent an unsigned integer,
* to a Java int
*/
/* public static int bytesToUintInt(byte[] bytes, int firstByte, int lastByte) {
int accum = 0;
int i = lastByte - firstByte;
if(i > 3) {
System.out.println("!!!! StaticProcs.bytesToUintLong() Can't convert more than 31 bits!");
return -1;
}
int stop = (i+1)*8;
for (int shiftBy = 0; shiftBy < stop; shiftBy += 8 ) {
accum |= ( (long)( bytes[firstByte + i] & 0xff ) ) << shiftBy;
i--;
}
return accum;
}*/
/**
* Recreates a UNIX timestamp based on the NTP representation used
* in RTCP SR packets
*
* @param ntpTs1 from RTCP SR packet
* @param ntpTs2 from RTCP SR packet
* @return the UNIX timestamp
*/
public static long undoNtpMess(long ntpTs1, long ntpTs2) {
long timeVal = (ntpTs1 - 2208988800L)*1000;
double tmp = (1000.0*(double)ntpTs2)/((double)4294967295L);
long ms = (long) tmp;
//System.out.println(" timeVal: " +Long.toString(timeVal)+ " ms " + Long.toString(ms));
timeVal += ms;
return timeVal;
}
/**
* Get the bits of a byte
*
* @param aByte the byte you wish to convert
* @return a String of 1's and 0's
*/
public static String bitsOfByte(byte aByte) {
int temp;
String out = "";
for(int i=7; i>=0; i--) {
temp = (aByte >>> i);
temp &= 0x0001;
out += (""+temp);
}
return out;
}
/**
* Get the hex representation of a byte
*
* @param aByte the byte you wish to convert
* @return a String of two chars 0-1,A-F
*/
public static String hexOfByte(byte aByte) {
String out = "";
for(int i=0; i<2; i++) {
int temp = (int) aByte;
if(temp < 0) {
temp +=256;
}
if(i == 0) {
temp = temp/16;
} else {
temp = temp%16;
}
if( temp > 9) {
switch(temp) {
case 10: out += "A"; break;
case 11: out += "B"; break;
case 12: out += "C"; break;
case 13: out += "D"; break;
case 14: out += "E"; break;
case 15: out += "F"; break;
}
} else {
out += Integer.toString(temp);
}
}
return out;
}
/**
* Get the hex representation of a byte
*
* @param hex 4 bytes the byte you wish to convert
* @return a String of two chars 0-1,A-F
*/
public static byte byteOfHex(byte[] hex) {
byte retByte = 0;
Byte tmp;
int val = 0;
// First 4 bits
tmp = hex[0];
val = tmp.intValue();
if(val > 64) {
// Letter
val -= 55;
} else {
// Number
val -= 48;
}
retByte = ((byte) (val << 4));
// Last 4 bits
tmp = hex[1];
val = tmp.intValue();
if(val > 64) {
// Letter
val -= 55;
} else {
// Number
val -= 48;
}
retByte |= ((byte) val);
return retByte;
}
/**
* Print the bits of a byte to standard out. For debugging.
*
* @param aByte the byte you wish to print out.
*/
public static void printBits(byte aByte) {
int temp;
for(int i=7; i>=0; i--) {
temp = (aByte >>> i);
temp &= 0x0001;
System.out.print(""+temp);
}
System.out.println();
}
public static String bitsOfBytes(byte[] bytes) {
String str = "";
//Expensive, but who cares
for(int i=0; i<bytes.length; i++ ) {
str += bitsOfByte(bytes[i]) + " ";
if((i + 1) % 4 == 0)
str += "\n";
}
return str;
}
}