public JpegReadStatusInt DecodeACFirst(JpegBinaryReader stream, float[] zz)
{
if (stream.eobRun > 0)
{
stream.eobRun--;
return(JpegReadStatusInt.GetSuccess());
}
for (int k = spectralStart; k <= spectralEnd; k++)
{
var status = ACTable.Decode(stream);
if (status.Status != Status.Success)
{
return(status);
}
int s = status.Result;
int r = s >> 4;
s &= 15;
if (s != 0)
{
k += r;
status = stream.ReadBits(s);
if (status.Status != Status.Success)
{
return(status);
}
r = status.Result;
s = HuffmanTable.Extend(r, s);
zz[k] = s << successiveLow;
}
else
{
if (r != 15)
{
stream.eobRun = 1 << r;
if (r != 0)
{
status = stream.ReadBits(r);
if (status.Status != Status.Success)
{
return(status);
}
stream.eobRun += status.Result;
}
stream.eobRun--;
break;
}
k += 15;
}
}
return(JpegReadStatusInt.GetSuccess());
}
/// <summary>
/// Generated from text on F-23, F.13 - Huffman decoded of AC coefficients
/// on ISO DIS 10918-1. Requirements and Guidelines.
/// </summary>
internal JpegReadStatusInt decode_ac_coefficients(JpegBinaryReader jpegStream, float[] zz)
{
var status = new JpegReadStatusInt();
for (int k = 1; k < 64; k++)
{
status = ACTable.Decode(jpegStream);
if (status.Status != Status.Success)
{
return(status);
}
int s = status.Result;
int r = s >> 4;
s &= 15;
if (s != 0)
{
k += r;
status = jpegStream.ReadBits(s);
if (status.Status != Status.Success)
{
return(status);
}
s = HuffmanTable.Extend(status.Result, s);
zz[k] = s;
}
else
{
if (r != 15)
{
//throw new JPEGMarkerFoundException();
return(status);
}
k += 15;
}
}
return(status);
}
public JpegReadStatusInt DecodeACRefine(JpegBinaryReader stream, float[] dest)
{
int p1 = 1 << successiveLow;
int m1 = (-1) << successiveLow;
int k = spectralStart;
if (stream.eobRun == 0)
{
for (; k <= spectralEnd; k++)
{
#region Decode and check S
var status = ACTable.Decode(stream);
if (status.Status != Status.Success)
{
return(status);
}
int s = status.Result;
int r = s >> 4;
s &= 15;
if (s != 0)
{
if (s != 1)
{
throw new Exception("Decode Error");
}
status = stream.ReadBits(1);
if (status.Status != Status.Success)
{
return(status);
}
s = status.Result == 1 ? p1 : m1;
}
else
{
if (r != 15)
{
stream.eobRun = 1 << r;
if (r > 0)
{
status = stream.ReadBits(r);
if (status.Status != Status.Success)
{
return(status);
}
stream.eobRun += status.Result;
}
break;
}
} // if (s != 0)
#endregion
// Apply the update
do
{
if (dest[k] != 0)
{
status = stream.ReadBits(1);
if (status.Status != Status.Success)
{
return(status);
}
if (status.Result == 1)
{
if (((int)dest[k] & p1) == 0)
{
if (dest[k] >= 0)
{
dest[k] += p1;
}
else
{
dest[k] += m1;
}
}
}
}
else
{
if (--r < 0)
{
break;
}
}
k++;
} while (k <= spectralEnd);
if ((s != 0) && k < 64)
{
dest[k] = s;
}
} // for k = start ... end
}
if (stream.eobRun > 0)
{
for (; k <= spectralEnd; k++)
{
if (dest[k] != 0)
{
var status = stream.ReadBits(1);
if (status.Status != Status.Success)
{
return(status);
}
if (status.Result == 1)
{
if (((int)dest[k] & p1) == 0)
{
if (dest[k] >= 0)
{
dest[k] += p1;
}
else
{
dest[k] += m1;
}
}
}
}
}
stream.eobRun--;
}
return(JpegReadStatusInt.GetSuccess());
}