/*
* Copyright 2007 Sun Microsystems, Inc.
*/
package com.sun.voip;
/**
* This class has static methods to convert between 8-bit ulaw data
* and 16-bit linear data.
*/
public class AudioConversion {
public static final int PCMU_SILENCE = 0x7f;
public static final int PCM_SILENCE = 0x0;
/*
* table for converting from linear to ulaw
*/
static private byte[] linearToUlawTable;
static {
long start = System.currentTimeMillis();
int BIAS = 0x84; // add-in bias for 16 bit samples
int CLIP = 32635;
int exp_lut[] = {
0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,
4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};
linearToUlawTable = new byte[65536];
for (int i = 0; i < 65536; i++) {
int sign, exponent, mantissa;
byte ulawbyte;
short sample = (short) i;
/* get the sample into sign-magnitude */
sign = (sample >> 8) & 0x80; // set aside the sign
if (sign != 0) {
sample = (short)-sample; // get magnitude
}
if (sample > CLIP) {
sample = (short) CLIP; // clip the magnitude
}
/* convert from 16 bit linear to ulaw */
sample = (short)(sample + BIAS);
exponent = exp_lut[(sample>>7) & 0xFF];
mantissa = (sample >> (exponent+3)) & 0x0F;
ulawbyte = (byte)(~(sign | (exponent << 4) | mantissa));
if (ulawbyte == 0) {
ulawbyte = 0x02; // optional CCITT trap
}
/*
* For debugging to match files sent and received
*/
//if (ulawbyte == 0xff) {
// ulawbyte = 0x7f;
//}
linearToUlawTable[i] = ulawbyte;
}
Logger.writeFile("Time to generate l2u table "
+ (System.currentTimeMillis() - start));
}
/*
* Index = ulaw value + 128, entry = signed 16 bit linear value.
*/
static final private int[] ulawToLinearTable = {
32635, 31608, 30584, 29560, 28536, 27512, 26488, 25464,
24440, 23416, 22392, 21368, 20344, 19320, 18296, 17272,
16248, 15736, 15224, 14712, 14200, 13688, 13176, 12664,
12152, 11640, 11128, 10616, 10104, 9592, 9080, 8568,
8056, 7800, 7544, 7288, 7032, 6776, 6520, 6264,
6008, 5752, 5496, 5240, 4984, 4728, 4472, 4216,
3960, 3832, 3704, 3576, 3448, 3320, 3192, 3064,
2936, 2808, 2680, 2552, 2424, 2296, 2168, 2040,
1912, 1848, 1784, 1720, 1656, 1592, 1528, 1464,
1400, 1336, 1272, 1208, 1144, 1080, 1016, 952,
888, 856, 824, 792, 760, 728, 696, 664,
632, 600, 568, 536, 504, 472, 440, 408,
376, 360, 344, 328, 312, 296, 280, 264,
248, 232, 216, 200, 184, 168, 152, 136,
120, 112, 104, 96, 88, 80, 72, 64,
56, 48, 40, 32, 24, 16, 8, 0,
-32760, -31608, -30584, -29560, -28536, -27512, -26488, -25464,
-24440, -23416, -22392, -21368, -20344, -19320, -18296, -17272,
-16248, -15736, -15224, -14712, -14200, -13688, -13176, -12664,
-12152, -11640, -11128, -10616, -10104, -9592, -9080, -8568,
-8056, -7800, -7544, -7288, -7032, -6776, -6520, -6264,
-6008, -5752, -5496, -5240, -4984, -4728, -4472, -4216,
-3960, -3832, -3704, -3576, -3448, -3320, -3192, -3064,
-2936, -2808, -2680, -2552, -2424, -2296, -2168, -2040,
-1912, -1848, -1784, -1720, -1656, -1592, -1528, -1464,
-1400, -1336, -1272, -1208, -1144, -1080, -1016, -952,
-888, -856, -824, -792, -760, -728, -696, -664,
-632, -600, -568, -536, -504, -472, -440, -408,
-376, -360, -344, -328, -312, -296, -280, -264,
-248, -232, -216, -200, -184, -168, -152, -136,
-120, -112, -104, -96, -88, -80, -72, -64,
-56, -48, -40, -32, -24, -16, -8, 0
};
/**
* Uninstantiable class.
*/
private AudioConversion() {}
/**
* Convert a ulaw byte array to a int array of linearData.
*
* @param ulawData byte array with ulaw data
* @param ulawOffset offset from the start of ulawData
* @param length length of ulawData
* @param linearData int array in which linear data will be placed
* @param linearOffset offset from the start of linearData
*/
public static void ulawToLinear(byte[] ulawData, int ulawOffset, int length,
int[] linearData) {
int inIx = ulawOffset;
for (int i = 0; i < length; i++) {
linearData[i] = ulawToLinearTable[ulawData[inIx] + 128];
inIx++;
}
}
public static void ulawToLinear(byte[] ulawData, int ulawOffset, int length,
byte[] linearData) {
ulawToLinear(ulawData, ulawOffset, length, linearData, 0);
}
public static void ulawToLinear(byte[] ulawData, int ulawOffset, int length,
byte[] linearData, int linearOffset) {
int inIx = ulawOffset;
int outIx = linearOffset;
for (int i = 0; i < length; i++) {
int s = ulawToLinearTable[ulawData[inIx] + 128];
linearData[outIx] = (byte) ((s >> 8) & 0xff);
outIx++;
linearData[outIx] = (byte) (s & 0xff);
outIx++;
inIx++;
}
}
/**
* Convert a linear byte array to a ulaw byte array starting from offset
* @param linearData byte array of linear data
* @param offset integer offset from start of the arrays
* @param ulawData byte array in which ulaw data will be placed
*/
public static void linearToUlaw(byte[] linearData,
byte[] ulawData, int ulawOffset) {
linearToUlaw(linearData, 0, ulawData, ulawOffset);
}
public static void linearToUlaw(byte[] linearData, int linearOffset,
byte[] ulawData, int ulawOffset) {
int outIx = ulawOffset;
for (int inIx = linearOffset; inIx < linearData.length; inIx += 2) {
ulawData[outIx++] = linearToUlaw(
(linearData[inIx] << 8) | (linearData[inIx + 1] & 0xff));
}
}
/**
* Convert a linear int array to a ulaw byte array starting from offset
* @param linearData int array of linear data
* @param offset integer offset from start of the arrays
* @param ulawData byte array in which ulaw data will be placed
*/
public static void linearToUlaw(int[] linearData, byte[] ulawData,
int ulawOffset) {
int outIx = ulawOffset;
for (int inIx = 0; inIx < linearData.length; inIx++) {
ulawData[outIx++] = linearToUlaw(linearData[inIx]);
}
}
/**
* Convert a linear int to a ulaw byte
*
* @param sample int with linear data
* @return byte of ulaw data
*/
public static byte linearToUlaw(int sample) {
return linearToUlawTable[sample & 0xffff];
}
public static void intsToBytes(int[] intData, byte[] byteData,
int outOffset) {
int outIx = outOffset;
for (int i = 0; i < intData.length; i++) {
byteData[outIx] = (byte) ((intData[i] >> 8) & 0xff);
byteData[outIx + 1] = (byte) (intData[i] & 0xff);
outIx += 2;
}
}
public static byte[] littleEndianIntsToBytes(int[] intData) {
byte[] byteData = new byte[intData.length * 2];
int outIx = 0;
for (int i = 0; i < intData.length; i++) {
byteData[outIx + 1] = (byte) ((intData[i] >> 8) & 0xff);
byteData[outIx] = (byte) (intData[i] & 0xff);
outIx += 2;
}
return byteData;
}
public static byte[] intsToBytes(int[] intData) {
byte[] byteData = new byte[intData.length * 2];
int outIx = 0;
for (int i = 0; i < intData.length; i++) {
byteData[outIx] = (byte) ((intData[i] >> 8) & 0xff);
byteData[outIx + 1] = (byte) (intData[i] & 0xff);
outIx += 2;
}
return byteData;
}
public static int[] bytesToLittleEndianInts(byte[] byteData) {
int[] intData = new int[byteData.length / 2];
int inIx = 0;
for (int i = 0; i < intData.length; i++) {
short s = (short) (((byteData[inIx + 1] << 8) & 0xff00) | (byteData[inIx] & 0xff));
intData[i] = (int) s;
inIx += 2;
}
return intData;
}
public static int[] bytesToInts(byte[] byteData) {
int[] intData = new int[byteData.length / 2];
int inIx = 0;
for (int i = 0; i < intData.length; i++) {
short s = (short) (((byteData[inIx] << 8) & 0xff00) |
(byteData[inIx + 1] & 0xff));
intData[i] = (int) s;
inIx += 2;
}
return intData;
}
public static void bytesToInts(byte[] byteData, int byteDataOffset,
int byteDataLength, int[] intData) {
int inIx = byteDataOffset;
for (int i = 0; i < intData.length; i++) {
short s = (short) (((byteData[inIx] << 8) & 0xff00) |
(byteData[inIx + 1] & 0xff));
intData[i] = (int) s;
inIx += 2;
}
}
public static short[] intsToShorts(int[] intData) {
short[] shortData = new short[intData.length];
for (int i = 0; i < intData.length; i++) {
shortData[i] = (short) intData[i];
}
return shortData;
}
public static int clip(int sample) {
if (sample > 32767) {
if (Logger.logLevel == -49) {
Logger.println("Clip " + sample + " to 0x7fff (32767)");
}
return 0x7fff;
}
if (sample < -32768) {
if (Logger.logLevel == -49) {
Logger.println("Clip " + sample + " to 0xffff8000 (-32768)");
}
return 0xffff8000;
}
return sample;
}
public static void clip(int[] data) {
for (int i = 0; i < data.length; i++) {
data[i] = clip(data[i]);
}
}
}