/**
* 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;
}
public static void uIntIntToByteWord(int i, byte[] byteWord, int srcPos) {
byteWord[0 + srcPos] = (byte) ((i >> 8) & 0x000000FF);
byteWord[1 + srcPos] = (byte) (i & 0x00FF);
}
/**
* 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;
}
public static void uIntLongToByteWord(long j, byte[] byteword, int srcPos) {
int i = (int) j;
byteword[0 + srcPos] = (byte) ((i >>> 24) & 0x000000FF);
byteword[1 + srcPos] = (byte) ((i >> 16) & 0x000000FF);
byteword[2 + srcPos] = (byte) ((i >> 8) & 0x000000FF);
byteword[3 + srcPos] = (byte) (i & 0x00FF);
}
/**
* 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;
}
}