public static void Initialize()
{
if (ht != null)
return;
ht = new Huffman[HTN];
ht[0] = new Huffman("0 ", 0, 0, 0, 0, -1, null, null, ValTab0, 0);
ht[1] = new Huffman("1 ", 2, 2, 0, 0, -1, null, null, ValTab1, 7);
ht[2] = new Huffman("2 ", 3, 3, 0, 0, -1, null, null, ValTab2, 17);
ht[3] = new Huffman("3 ", 3, 3, 0, 0, -1, null, null, ValTab3, 17);
ht[4] = new Huffman("4 ", 0, 0, 0, 0, -1, null, null, ValTab4, 0);
ht[5] = new Huffman("5 ", 4, 4, 0, 0, -1, null, null, ValTab5, 31);
ht[6] = new Huffman("6 ", 4, 4, 0, 0, -1, null, null, ValTab6, 31);
ht[7] = new Huffman("7 ", 6, 6, 0, 0, -1, null, null, ValTab7, 71);
ht[8] = new Huffman("8 ", 6, 6, 0, 0, -1, null, null, ValTab8, 71);
ht[9] = new Huffman("9 ", 6, 6, 0, 0, -1, null, null, ValTab9, 71);
ht[10] = new Huffman("10 ", 8, 8, 0, 0, -1, null, null, ValTab10, 127);
ht[11] = new Huffman("11 ", 8, 8, 0, 0, -1, null, null, ValTab11, 127);
ht[12] = new Huffman("12 ", 8, 8, 0, 0, -1, null, null, ValTab12, 127);
ht[13] = new Huffman("13 ", 16, 16, 0, 0, -1, null, null, ValTab13, 511);
ht[14] = new Huffman("14 ", 0, 0, 0, 0, -1, null, null, ValTab14, 0);
ht[15] = new Huffman("15 ", 16, 16, 0, 0, -1, null, null, ValTab15, 511);
ht[16] = new Huffman("16 ", 16, 16, 1, 1, -1, null, null, ValTab16, 511);
ht[17] = new Huffman("17 ", 16, 16, 2, 3, 16, null, null, ValTab16, 511);
ht[18] = new Huffman("18 ", 16, 16, 3, 7, 16, null, null, ValTab16, 511);
ht[19] = new Huffman("19 ", 16, 16, 4, 15, 16, null, null, ValTab16, 511);
ht[20] = new Huffman("20 ", 16, 16, 6, 63, 16, null, null, ValTab16, 511);
ht[21] = new Huffman("21 ", 16, 16, 8, 255, 16, null, null, ValTab16, 511);
ht[22] = new Huffman("22 ", 16, 16, 10, 1023, 16, null, null, ValTab16, 511);
ht[23] = new Huffman("23 ", 16, 16, 13, 8191, 16, null, null, ValTab16, 511);
ht[24] = new Huffman("24 ", 16, 16, 4, 15, -1, null, null, ValTab24, 512);
ht[25] = new Huffman("25 ", 16, 16, 5, 31, 24, null, null, ValTab24, 512);
ht[26] = new Huffman("26 ", 16, 16, 6, 63, 24, null, null, ValTab24, 512);
ht[27] = new Huffman("27 ", 16, 16, 7, 127, 24, null, null, ValTab24, 512);
ht[28] = new Huffman("28 ", 16, 16, 8, 255, 24, null, null, ValTab24, 512);
ht[29] = new Huffman("29 ", 16, 16, 9, 511, 24, null, null, ValTab24, 512);
ht[30] = new Huffman("30 ", 16, 16, 11, 2047, 24, null, null, ValTab24, 512);
ht[31] = new Huffman("31 ", 16, 16, 13, 8191, 24, null, null, ValTab24, 512);
ht[32] = new Huffman("32 ", 1, 16, 0, 0, -1, null, null, ValTab32, 31);
ht[33] = new Huffman("33 ", 1, 16, 0, 0, -1, null, null, ValTab33, 31);
}
/// <summary>
/// Do the huffman-decoding.
/// NOTE: for counta, countb -the 4 bit value is returned in y, discard x.
/// </summary>
public static int Decode(Huffman h, int[] x, int[] y, int[] v, int[] w, BitReserve br)
{
// array of all huffcodtable headers
// 0..31 Huffman code table 0..31
// 32,33 count1-tables
int dmask = 1 << ((4*8) - 1);
int point = 0;
int error = 1;
int level = dmask;
if (h.val == null)
return 2;
/* table 0 needs no bits */
if (h.treelen == 0)
{
x[0] = y[0] = 0;
return 0;
}
/* Lookup in Huffman table. */
/*int bitsAvailable = 0;
int bitIndex = 0;
int bits[] = bitbuf;*/
do
{
if (h.val[point][0] == 0)
{
/*end of tree*/
x[0] = SupportClass.URShift(h.val[point][1], 4);
y[0] = h.val[point][1] & 0xf;
error = 0;
break;
}
// hget1bit() is called thousands of times, and so needs to be
// ultra fast.
/*
if (bitIndex==bitsAvailable)
{
bitsAvailable = br.readBits(bits, 32);
bitIndex = 0;
}
*/
//if (bits[bitIndex++]!=0)
if (br.ReadOneBit() != 0)
{
while (h.val[point][1] >= MXOFF)
point += h.val[point][1];
point += h.val[point][1];
}
else
{
while (h.val[point][0] >= MXOFF)
point += h.val[point][0];
point += h.val[point][0];
}
level = SupportClass.URShift(level, 1);
// MDM: ht[0] is always 0;
} while ((level != 0) || (point < 0));
// put back any bits not consumed
/*
int unread = (bitsAvailable-bitIndex);
if (unread>0)
br.rewindNbits(unread);
*/
/* Process sign encodings for quadruples tables. */
// System.out.println(h.tablename);
if (h.tablename0 == '3' && (h.tablename1 == '2' || h.tablename1 == '3'))
{
v[0] = (y[0] >> 3) & 1;
w[0] = (y[0] >> 2) & 1;
x[0] = (y[0] >> 1) & 1;
y[0] = y[0] & 1;
/* v, w, x and y are reversed in the bitstream.
switch them around to make test bistream work. */
if (v[0] != 0)
if (br.ReadOneBit() != 0)
v[0] = -v[0];
if (w[0] != 0)
if (br.ReadOneBit() != 0)
w[0] = -w[0];
if (x[0] != 0)
if (br.ReadOneBit() != 0)
x[0] = -x[0];
if (y[0] != 0)
if (br.ReadOneBit() != 0)
y[0] = -y[0];
}
else
{
// Process sign and escape encodings for dual tables.
// x and y are reversed in the test bitstream.
// Reverse x and y here to make test bitstream work.
if (h.linbits != 0)
if ((h.xlen - 1) == x[0])
x[0] += br.ReadBits(h.linbits);
if (x[0] != 0)
if (br.ReadOneBit() != 0)
x[0] = -x[0];
if (h.linbits != 0)
if ((h.ylen - 1) == y[0])
y[0] += br.ReadBits(h.linbits);
if (y[0] != 0)
if (br.ReadOneBit() != 0)
y[0] = -y[0];
}
return error;
}