// Constructor Method
public HuffmanDecode(Stream data)
{
size = (int)data.Length;
dis = new EmbedData(data);
// Parse out markers and header info
bool cont = true;
byte b;
while (cont)
{
b = dis.Read();
if (b == 255)
{
b = dis.Read();
switch (b)
{
case 192:
SetSOF0();
break;
case 196:
SetDHT();
break;
case 219:
SetDQT();
break;
case 217:
case 218:
cont = false;
break;
case DRI:
SetDRI();
break;
default:
if (Array.IndexOf(APP, b) > -1)
{
dis.Seek(dis.ReadInt() - 2, SeekOrigin.Current);
}
break;
}
}
}
}
/// <summary>
/// Return image data
/// </summary>
public int[] Decode()
{
int tmp;
int[] Cs, Ta, Td; // SOS parameters
int[] PRED = new int[Nf];
for (int nComponent = 0; nComponent < Nf; nComponent++)
{
PRED[nComponent] = 0;
}
CNT = 0;
// Read in Scan Header information
Ls = dis.ReadInt();
Ns = dis.Read();
Cs = new int[Ns];
Td = new int[Ns];
Ta = new int[Ns];
// get table information
for (i = 0; i < Ns; i++)
{
Cs[i] = dis.Read();
Td[i] = dis.Read();
Ta[i] = Td[i] & 0x0f;
Td[i] >>= 4;
}
Ss = dis.Read();
Se = dis.Read();
Ah = dis.Read();
Al = Ah & 0x0f;
Ah >>= 4;
// Calculate the Number of blocks encoded
// warum doppelt so viel?
int[] buff = new int[2 * 8 * 8 * GetBlockCount()];
int pos = 0;
int MCUCount = 0;
bool bDoIt = true;
while (bDoIt)
{
// Get component 1 of MCU
for (int nComponent = 0; nComponent < Nf; nComponent++)
{
for (j = 0; j < H[nComponent] * V[nComponent]; j++)
{
// Get DC coefficient
hftbl = Td[nComponent] * 2;
tmp = DECODE();
Diff = Receive(tmp);
ZZ[0] = PRED[0] + Extend(Diff, tmp);
PRED[nComponent] = ZZ[0];
// Get AC coefficients
hftbl = Ta[nComponent] * 2 + 1;
Decode_AC_Coefficients();
for (i = 0; i < 64; i++)
{
// Zickzack???
// buff[pos++]=ZZ[deZigZag[lp]];
buff[pos++] = ZZ[i];
}
}
}
MCUCount++;
if (MCUCount == RI)
{
MCUCount = 0;
CNT = 0;
for (int nComponent = 0; nComponent < Nf; nComponent++)
{
PRED[nComponent] = 0;
}
dis.Read();
int tmpB = dis.Read();
if (tmpB == EOI)
{
break;
}
}
if (dis.Available <= 2)
{
if (dis.Available == 2)
{
dis.Read();
if (dis.Read() != EOI)
{
logger.Warn("file does not end with EOI");
}
}
else
{
logger.Warn("file does not end with EOI");
}
break;
}
}
Array.Resize(ref buff, pos);
return(buff);
}