private int readEOL() {
if (fillBits == 0) {
if (nextNBits(12) != 1) {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder6"));
}
} else if (fillBits == 1) {
// First EOL code word xxxx 0000 0000 0001 will occur
// As many fill bits will be present as required to make
// the EOL code of 12 bits end on a byte boundary.
int bitsLeft = 8 - bitPointer;
if (nextNBits(bitsLeft) != 0) {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder8"));
}
// If the number of bitsLeft is less than 8, then to have a 12
// bit EOL sequence, two more bytes are certainly going to be
// required. The first of them has to be all zeros, so ensure
// that.
if (bitsLeft < 4) {
if (nextNBits(8) != 0) {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder8"));
}
}
// There might be a random number of fill bytes with 0s, so
// loop till the EOL of 0000 0001 is found, as long as all
// the bytes preceding it are 0's.
int n;
while ((n = nextNBits(8)) != 1) {
// If not all zeros
if (n != 0) {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder8"));
}
}
}
// If one dimensional encoding mode, then always return 1
if (oneD == 0) {
return 1;
} else {
// Otherwise for 2D encoding mode,
// The next one bit signifies 1D/2D encoding of next line.
return nextLesserThan8Bits(1);
}
}
// Returns run length
private int decodeWhiteCodeWord() {
int current, entry, bits, isT, twoBits, code = -1;
int runLength = 0;
boolean isWhite = true;
while (isWhite) {
current = nextNBits(10);
entry = white[current];
// Get the 3 fields from the entry
isT = entry & 0x0001;
bits = (entry >>> 1) & 0x0f;
if (bits == 12) { // Additional Make up code
// Get the next 2 bits
twoBits = nextLesserThan8Bits(2);
// Consolidate the 2 new bits and last 2 bits into 4 bits
current = ((current << 2) & 0x000c) | twoBits;
entry = additionalMakeup[current];
bits = (entry >>> 1) & 0x07; // 3 bits 0000 0111
code = (entry >>> 4) & 0x0fff; // 12 bits
runLength += code;
updatePointer(4 - bits);
} else if (bits == 0) { // ERROR
throw new Error(JaiI18N.getString("XTIFFFaxDecoder0"));
} else if (bits == 15) { // EOL
throw new Error(JaiI18N.getString("XTIFFFaxDecoder1"));
} else {
// 11 bits - 0000 0111 1111 1111 = 0x07ff
code = (entry >>> 5) & 0x07ff;
runLength += code;
updatePointer(10 - bits);
if (isT == 0) {
isWhite = false;
}
}
}
return runLength;
}
private int nextLesserThan8Bits(int bitsToGet) {
byte b, next;
int l = data.length - 1;
int bp = this.bytePointer;
if (fillOrder == 1) {
b = data[bp];
if (bp == l) {
next = 0x00;
} else {
next = data[bp + 1];
}
} else if (fillOrder == 2) {
b = flipTable[data[bp] & 0xff];
if (bp == l) {
next = 0x00;
} else {
next = flipTable[data[bp + 1] & 0xff];
}
} else {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder7"));
}
int bitsLeft = 8 - bitPointer;
int bitsFromNextByte = bitsToGet - bitsLeft;
int shift = bitsLeft - bitsToGet;
int i1, i2;
if (shift >= 0) {
i1 = (b & table1[bitsLeft]) >>> shift;
bitPointer += bitsToGet;
if (bitPointer == 8) {
bitPointer = 0;
bytePointer++;
}
} else {
i1 = (b & table1[bitsLeft]) << (-shift);
i2 = (next & table2[bitsFromNextByte]) >>> (8 - bitsFromNextByte);
i1 |= i2;
bytePointer++;
bitPointer = bitsFromNextByte;
}
return i1;
}
private int nextNBits(int bitsToGet) {
byte b, next, next2next;
int l = data.length - 1;
int bp = this.bytePointer;
if (fillOrder == 1) {
b = data[bp];
if (bp == l) {
next = 0x00;
next2next = 0x00;
} else if ((bp + 1) == l) {
next = data[bp + 1];
next2next = 0x00;
} else {
next = data[bp + 1];
next2next = data[bp + 2];
}
} else if (fillOrder == 2) {
b = flipTable[data[bp] & 0xff];
if (bp == l) {
next = 0x00;
next2next = 0x00;
} else if ((bp + 1) == l) {
next = flipTable[data[bp + 1] & 0xff];
next2next = 0x00;
} else {
next = flipTable[data[bp + 1] & 0xff];
next2next = flipTable[data[bp + 2] & 0xff];
}
} else {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder7"));
}
int bitsLeft = 8 - bitPointer;
int bitsFromNextByte = bitsToGet - bitsLeft;
int bitsFromNext2NextByte = 0;
if (bitsFromNextByte > 8) {
bitsFromNext2NextByte = bitsFromNextByte - 8;
bitsFromNextByte = 8;
}
bytePointer++;
int i1 = (b & table1[bitsLeft]) << (bitsToGet - bitsLeft);
int i2 = (next & table2[bitsFromNextByte]) >>> (8 - bitsFromNextByte);
int i3 = 0;
if (bitsFromNext2NextByte != 0) {
i2 <<= bitsFromNext2NextByte;
i3 = (next2next & table2[bitsFromNext2NextByte]) >>> (8 - bitsFromNext2NextByte);
i2 |= i3;
bytePointer++;
bitPointer = bitsFromNext2NextByte;
} else {
if (bitsFromNextByte == 8) {
bitPointer = 0;
bytePointer++;
} else {
bitPointer = bitsFromNextByte;
}
}
int i = i1 | i2;
return i;
}
// Returns run length
private int decodeBlackCodeWord() {
int current, entry, bits, isT, twoBits, code = -1;
int runLength = 0;
boolean isWhite = false;
while (!isWhite) {
current = nextLesserThan8Bits(4);
entry = initBlack[current];
// Get the 3 fields from the entry
isT = entry & 0x0001;
bits = (entry >>> 1) & 0x000f;
code = (entry >>> 5) & 0x07ff;
if (code == 100) {
current = nextNBits(9);
entry = black[current];
// Get the 3 fields from the entry
isT = entry & 0x0001;
bits = (entry >>> 1) & 0x000f;
code = (entry >>> 5) & 0x07ff;
if (bits == 12) {
// Additional makeup codes
updatePointer(5);
current = nextLesserThan8Bits(4);
entry = additionalMakeup[current];
bits = (entry >>> 1) & 0x07; // 3 bits 0000 0111
code = (entry >>> 4) & 0x0fff; // 12 bits
runLength += code;
updatePointer(4 - bits);
} else if (bits == 15) {
// EOL code
throw new Error(JaiI18N.getString("XTIFFFaxDecoder2"));
} else {
runLength += code;
updatePointer(9 - bits);
if (isT == 0) {
isWhite = true;
}
}
} else if (code == 200) {
// Is a Terminating code
current = nextLesserThan8Bits(2);
entry = twoBitBlack[current];
code = (entry >>> 5) & 0x07ff;
runLength += code;
bits = (entry >>> 1) & 0x0f;
updatePointer(2 - bits);
isWhite = true;
} else {
// Is a Terminating code
runLength += code;
updatePointer(4 - bits);
isWhite = true;
}
}
return runLength;
}
public synchronized void decodeT6(
byte[] buffer, byte[] compData, int startX, int height, long tiffT6Options) {
this.data = compData;
compression = 4;
bitPointer = 0;
bytePointer = 0;
int scanlineStride = (w + 7) / 8;
int bufferOffset = 0;
int a0, a1, b1, b2;
int entry, code, bits;
byte color;
boolean isWhite;
int currIndex;
int temp[];
// Return values from getNextChangingElement
int[] b = new int[2];
// uncompressedMode - have written some code for this, but this
// has not been tested due to lack of test images using this optional
// extension. This code is when code == 11. aastha 03/03/1999
uncompressedMode = (int) ((tiffT6Options & 0x02) >> 1);
// Local cached reference
int[] cce = currChangingElems;
// Assume invisible preceding row of all white pixels and insert
// both black and white changing elements beyond the end of this
// imaginary scanline.
changingElemSize = 0;
cce[changingElemSize++] = w;
cce[changingElemSize++] = w;
int lineOffset = 0;
int bitOffset;
for (int lines = 0; lines < height; lines++) {
// a0 has to be set just before the start of the scanline.
a0 = -1;
isWhite = true;
// Assign the changing elements of the previous scanline to
// prevChangingElems and start putting this new scanline's
// changing elements into the currChangingElems.
temp = prevChangingElems;
prevChangingElems = currChangingElems;
cce = currChangingElems = temp;
currIndex = 0;
// Start decoding the scanline at startX in the raster
bitOffset = startX;
// Reset search start position for getNextChangingElement
lastChangingElement = 0;
// Till one whole scanline is decoded
while (bitOffset < w) {
// Get the next changing element
getNextChangingElement(a0, isWhite, b);
b1 = b[0];
b2 = b[1];
// Get the next seven bits
entry = nextLesserThan8Bits(7);
// Run these through the 2DCodes table
entry = (int) (twoDCodes[entry] & 0xff);
// Get the code and the number of bits used up
code = (entry & 0x78) >>> 3;
bits = entry & 0x07;
if (code == 0) { // Pass
// We always assume WhiteIsZero format for fax.
if (!isWhite) {
setToBlack(buffer, lineOffset, bitOffset, b2 - bitOffset);
}
bitOffset = a0 = b2;
// Set pointer to only consume the correct number of bits.
updatePointer(7 - bits);
} else if (code == 1) { // Horizontal
// Set pointer to only consume the correct number of bits.
updatePointer(7 - bits);
// identify the next 2 alternating color codes.
int number;
if (isWhite) {
// Following are white and black runs
number = decodeWhiteCodeWord();
bitOffset += number;
cce[currIndex++] = bitOffset;
number = decodeBlackCodeWord();
setToBlack(buffer, lineOffset, bitOffset, number);
bitOffset += number;
cce[currIndex++] = bitOffset;
} else {
// First a black run and then a white run follows
number = decodeBlackCodeWord();
setToBlack(buffer, lineOffset, bitOffset, number);
bitOffset += number;
cce[currIndex++] = bitOffset;
number = decodeWhiteCodeWord();
bitOffset += number;
cce[currIndex++] = bitOffset;
}
a0 = bitOffset;
} else if (code <= 8) { // Vertical
a1 = b1 + (code - 5);
cce[currIndex++] = a1;
// We write the current color till a1 - 1 pos,
// since a1 is where the next color starts
if (!isWhite) {
setToBlack(buffer, lineOffset, bitOffset, a1 - bitOffset);
}
bitOffset = a0 = a1;
isWhite = !isWhite;
updatePointer(7 - bits);
} else if (code == 11) {
if (nextLesserThan8Bits(3) != 7) {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder5"));
}
int zeros = 0;
boolean exit = false;
while (!exit) {
while (nextLesserThan8Bits(1) != 1) {
zeros++;
}
if (zeros > 5) {
// Exit code
// Zeros before exit code
zeros = zeros - 6;
if (!isWhite && (zeros > 0)) {
cce[currIndex++] = bitOffset;
}
// Zeros before the exit code
bitOffset += zeros;
if (zeros > 0) {
// Some zeros have been written
isWhite = true;
}
// Read in the bit which specifies the color of
// the following run
if (nextLesserThan8Bits(1) == 0) {
if (!isWhite) {
cce[currIndex++] = bitOffset;
}
isWhite = true;
} else {
if (isWhite) {
cce[currIndex++] = bitOffset;
}
isWhite = false;
}
exit = true;
}
if (zeros == 5) {
if (!isWhite) {
cce[currIndex++] = bitOffset;
}
bitOffset += zeros;
// Last thing written was white
isWhite = true;
} else {
bitOffset += zeros;
cce[currIndex++] = bitOffset;
setToBlack(buffer, lineOffset, bitOffset, 1);
++bitOffset;
// Last thing written was black
isWhite = false;
}
}
} else {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder5"));
}
}
// Add the changing element beyond the current scanline for the
// other color too
cce[currIndex++] = bitOffset;
// Number of changing elements in this scanline.
changingElemSize = currIndex;
lineOffset += scanlineStride;
}
}
public void decode2D(byte[] buffer, byte compData[], int startX, int height, long tiffT4Options) {
this.data = compData;
compression = 3;
bitPointer = 0;
bytePointer = 0;
int scanlineStride = (w + 7) / 8;
int a0, a1, b1, b2;
int[] b = new int[2];
int entry, code, bits, color;
boolean isWhite;
int currIndex = 0;
int temp[];
// fillBits - dealt with this in readEOL
// 1D/2D encoding - dealt with this in readEOL
// uncompressedMode - haven't dealt with this yet.
// TODO: Deal with uncompressedMode, aastha 03/03/1999
oneD = (int) (tiffT4Options & 0x01);
uncompressedMode = (int) ((tiffT4Options & 0x02) >> 1);
fillBits = (int) ((tiffT4Options & 0x04) >> 2);
// The data must start with an EOL code
if (readEOL() != 1) {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder3"));
}
int lineOffset = 0;
int bitOffset;
// Then the 1D encoded scanline data will occur, changing elements
// array gets set.
decodeNextScanline(buffer, lineOffset, startX);
lineOffset += scanlineStride;
for (int lines = 1; lines < height; lines++) {
// Every line must begin with an EOL followed by a bit which
// indicates whether the following scanline is 1D or 2D encoded.
if (readEOL() == 0) {
// 2D encoded scanline follows
// Initialize previous scanlines changing elements, and
// initialize current scanline's changing elements array
temp = prevChangingElems;
prevChangingElems = currChangingElems;
currChangingElems = temp;
currIndex = 0;
// a0 has to be set just before the start of this scanline.
a0 = -1;
isWhite = true;
bitOffset = startX;
lastChangingElement = 0;
while (bitOffset < w) {
// Get the next changing element
getNextChangingElement(a0, isWhite, b);
b1 = b[0];
b2 = b[1];
// Get the next seven bits
entry = nextLesserThan8Bits(7);
// Run these through the 2DCodes table
entry = (int) (twoDCodes[entry] & 0xff);
// Get the code and the number of bits used up
code = (entry & 0x78) >>> 3;
bits = entry & 0x07;
if (code == 0) {
if (!isWhite) {
setToBlack(buffer, lineOffset, bitOffset, b2 - bitOffset);
}
bitOffset = a0 = b2;
// Set pointer to consume the correct number of bits.
updatePointer(7 - bits);
} else if (code == 1) {
// Horizontal
updatePointer(7 - bits);
// identify the next 2 codes.
int number;
if (isWhite) {
number = decodeWhiteCodeWord();
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
number = decodeBlackCodeWord();
setToBlack(buffer, lineOffset, bitOffset, number);
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
} else {
number = decodeBlackCodeWord();
setToBlack(buffer, lineOffset, bitOffset, number);
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
number = decodeWhiteCodeWord();
bitOffset += number;
currChangingElems[currIndex++] = bitOffset;
}
a0 = bitOffset;
} else if (code <= 8) {
// Vertical
a1 = b1 + (code - 5);
currChangingElems[currIndex++] = a1;
// We write the current color till a1 - 1 pos,
// since a1 is where the next color starts
if (!isWhite) {
setToBlack(buffer, lineOffset, bitOffset, a1 - bitOffset);
}
bitOffset = a0 = a1;
isWhite = !isWhite;
updatePointer(7 - bits);
} else {
throw new Error(JaiI18N.getString("XTIFFFaxDecoder4"));
}
}
// Add the changing element beyond the current scanline for the
// other color too
currChangingElems[currIndex++] = bitOffset;
changingElemSize = currIndex;
} else {
// 1D encoded scanline follows
decodeNextScanline(buffer, lineOffset, startX);
}
lineOffset += scanlineStride;
}
}
public void decodeNextScanline(byte[] buffer, int lineOffset, int bitOffset) {
int bits = 0, code = 0, isT = 0;
int current, entry, twoBits;
boolean isWhite = true;
int dstEnd = 0;
// Initialize starting of the changing elements array
changingElemSize = 0;
// While scanline not complete
while (bitOffset < w) {
while (isWhite) {
// White run
current = nextNBits(10);
entry = white[current];
// Get the 3 fields from the entry
isT = entry & 0x0001;
bits = (entry >>> 1) & 0x0f;
if (bits == 12) { // Additional Make up code
// Get the next 2 bits
twoBits = nextLesserThan8Bits(2);
// Consolidate the 2 new bits and last 2 bits into 4 bits
current = ((current << 2) & 0x000c) | twoBits;
entry = additionalMakeup[current];
bits = (entry >>> 1) & 0x07; // 3 bits 0000 0111
code = (entry >>> 4) & 0x0fff; // 12 bits
bitOffset += code; // Skip white run
updatePointer(4 - bits);
} else if (bits == 0) { // ERROR
throw new Error(JaiI18N.getString("XTIFFFaxDecoder0"));
} else if (bits == 15) { // EOL
throw new Error(JaiI18N.getString("XTIFFFaxDecoder1"));
} else {
// 11 bits - 0000 0111 1111 1111 = 0x07ff
code = (entry >>> 5) & 0x07ff;
bitOffset += code;
updatePointer(10 - bits);
if (isT == 0) {
isWhite = false;
currChangingElems[changingElemSize++] = bitOffset;
}
}
}
// Check whether this run completed one width, if so
// advance to next byte boundary for compression = 2.
if (bitOffset == w) {
if (compression == 2) {
advancePointer();
}
break;
}
while (isWhite == false) {
// Black run
current = nextLesserThan8Bits(4);
entry = initBlack[current];
// Get the 3 fields from the entry
isT = entry & 0x0001;
bits = (entry >>> 1) & 0x000f;
code = (entry >>> 5) & 0x07ff;
if (code == 100) {
current = nextNBits(9);
entry = black[current];
// Get the 3 fields from the entry
isT = entry & 0x0001;
bits = (entry >>> 1) & 0x000f;
code = (entry >>> 5) & 0x07ff;
if (bits == 12) {
// Additional makeup codes
updatePointer(5);
current = nextLesserThan8Bits(4);
entry = additionalMakeup[current];
bits = (entry >>> 1) & 0x07; // 3 bits 0000 0111
code = (entry >>> 4) & 0x0fff; // 12 bits
setToBlack(buffer, lineOffset, bitOffset, code);
bitOffset += code;
updatePointer(4 - bits);
} else if (bits == 15) {
// EOL code
throw new Error(JaiI18N.getString("XTIFFFaxDecoder2"));
} else {
setToBlack(buffer, lineOffset, bitOffset, code);
bitOffset += code;
updatePointer(9 - bits);
if (isT == 0) {
isWhite = true;
currChangingElems[changingElemSize++] = bitOffset;
}
}
} else if (code == 200) {
// Is a Terminating code
current = nextLesserThan8Bits(2);
entry = twoBitBlack[current];
code = (entry >>> 5) & 0x07ff;
bits = (entry >>> 1) & 0x0f;
setToBlack(buffer, lineOffset, bitOffset, code);
bitOffset += code;
updatePointer(2 - bits);
isWhite = true;
currChangingElems[changingElemSize++] = bitOffset;
} else {
// Is a Terminating code
setToBlack(buffer, lineOffset, bitOffset, code);
bitOffset += code;
updatePointer(4 - bits);
isWhite = true;
currChangingElems[changingElemSize++] = bitOffset;
}
}
// Check whether this run completed one width
if (bitOffset == w) {
if (compression == 2) {
advancePointer();
}
break;
}
}
currChangingElems[changingElemSize++] = bitOffset;
}