public virtual void start_pass()
{
J_DCT_METHOD method = 0;
for (int ci = 0; ci < m_cinfo.m_num_components; ci++)
{
/* Select the proper DCT routine for this component's scaling */
jpeg_component_info compptr = m_cinfo.Component_info[ci];
switch ((compptr.DCT_h_scaled_size << 8) + compptr.DCT_v_scaled_size)
{
case ((1 << 8) + 1):
do_dct[ci] = jpeg_fdct_1x1;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((2 << 8) + 2):
do_dct[ci] = jpeg_fdct_2x2;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((3 << 8) + 3):
do_dct[ci] = jpeg_fdct_3x3;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((4 << 8) + 4):
do_dct[ci] = jpeg_fdct_4x4;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((5 << 8) + 5):
do_dct[ci] = jpeg_fdct_5x5;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((6 << 8) + 6):
do_dct[ci] = jpeg_fdct_6x6;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((7 << 8) + 7):
do_dct[ci] = jpeg_fdct_7x7;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((9 << 8) + 9):
do_dct[ci] = jpeg_fdct_9x9;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((10 << 8) + 10):
do_dct[ci] = jpeg_fdct_10x10;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((11 << 8) + 11):
do_dct[ci] = jpeg_fdct_11x11;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((12 << 8) + 12):
do_dct[ci] = jpeg_fdct_12x12;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((13 << 8) + 13):
do_dct[ci] = jpeg_fdct_13x13;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((14 << 8) + 14):
do_dct[ci] = jpeg_fdct_14x14;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((15 << 8) + 15):
do_dct[ci] = jpeg_fdct_15x15;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((16 << 8) + 16):
do_dct[ci] = jpeg_fdct_16x16;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((16 << 8) + 8):
do_dct[ci] = jpeg_fdct_16x8;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((14 << 8) + 7):
do_dct[ci] = jpeg_fdct_14x7;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((12 << 8) + 6):
do_dct[ci] = jpeg_fdct_12x6;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((10 << 8) + 5):
do_dct[ci] = jpeg_fdct_10x5;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((8 << 8) + 4):
do_dct[ci] = jpeg_fdct_8x4;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((6 << 8) + 3):
do_dct[ci] = jpeg_fdct_6x3;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((4 << 8) + 2):
do_dct[ci] = jpeg_fdct_4x2;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((2 << 8) + 1):
do_dct[ci] = jpeg_fdct_2x1;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((8 << 8) + 16):
do_dct[ci] = jpeg_fdct_8x16;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((7 << 8) + 14):
do_dct[ci] = jpeg_fdct_7x14;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((6 << 8) + 12):
do_dct[ci] = jpeg_fdct_6x12;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((5 << 8) + 10):
do_dct[ci] = jpeg_fdct_5x10;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((4 << 8) + 8):
do_dct[ci] = jpeg_fdct_4x8;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((3 << 8) + 6):
do_dct[ci] = jpeg_fdct_3x6;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((2 << 8) + 4):
do_dct[ci] = jpeg_fdct_2x4;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((1 << 8) + 2):
do_dct[ci] = jpeg_fdct_1x2;
method = J_DCT_METHOD.JDCT_ISLOW; /* jfdctint uses islow-style table */
break;
case ((JpegConstants.DCTSIZE << 8) + JpegConstants.DCTSIZE):
switch (m_cinfo.m_dct_method)
{
case J_DCT_METHOD.JDCT_ISLOW:
do_dct[ci] = jpeg_fdct_islow;
method = J_DCT_METHOD.JDCT_ISLOW;
break;
case J_DCT_METHOD.JDCT_IFAST:
do_dct[ci] = jpeg_fdct_ifast;
method = J_DCT_METHOD.JDCT_IFAST;
break;
case J_DCT_METHOD.JDCT_FLOAT:
do_float_dct[ci] = jpeg_fdct_float;
method = J_DCT_METHOD.JDCT_FLOAT;
break;
default:
m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_NOT_COMPILED);
break;
}
break;
default:
m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_BAD_DCTSIZE, compptr.DCT_h_scaled_size, compptr.DCT_v_scaled_size);
break;
}
int qtblno = m_cinfo.Component_info[ci].Quant_tbl_no;
/* Make sure specified quantization table is present */
if (qtblno < 0 || qtblno >= JpegConstants.NUM_QUANT_TBLS || m_cinfo.m_quant_tbl_ptrs[qtblno] == null)
m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_NO_QUANT_TABLE, qtblno);
JQUANT_TBL qtbl = m_cinfo.m_quant_tbl_ptrs[qtblno];
int[] dtbl;
/* Create divisor table from quant table */
int i = 0;
switch (method)
{
case J_DCT_METHOD.JDCT_ISLOW:
/* For LL&M IDCT method, divisors are equal to raw quantization
* coefficients multiplied by 8 (to counteract scaling).
*/
dtbl = m_dctTables[ci].int_array;
for (i = 0; i < JpegConstants.DCTSIZE2; i++)
dtbl[i] = ((int)qtbl.quantval[i]) << (compptr.component_needed ? 4 : 3);
forward_DCT[ci] = forwardDCTImpl;
break;
case J_DCT_METHOD.JDCT_IFAST:
dtbl = m_dctTables[ci].int_array;
for (i = 0; i < JpegConstants.DCTSIZE2; i++)
dtbl[i] = JpegUtils.DESCALE((int)qtbl.quantval[i] * (int)aanscales[i], compptr.component_needed ? CONST_BITS - 4 : CONST_BITS - 3);
forward_DCT[ci] = forwardDCTImpl;
break;
case J_DCT_METHOD.JDCT_FLOAT:
float[] fdtbl = m_dctTables[ci].float_array;
i = 0;
for (int row = 0; row < JpegConstants.DCTSIZE; row++)
{
for (int col = 0; col < JpegConstants.DCTSIZE; col++)
{
fdtbl[i] = (float)(1.0 / (((double)qtbl.quantval[i] * aanscalefactor[row] * aanscalefactor[col] * (compptr.component_needed ? 16.0 : 8.0))));
i++;
}
}
forward_DCT[ci] = forwardDCTFloatImpl;
break;
default:
m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_NOT_COMPILED);
break;
}
}
}
