// Initialize tables for YCC->RGB colorspace conversion.
// This is taken directly from jdcolor.cs; see that file for more info.
static void build_ycc_rgb_table_upsample(jpeg_decompress cinfo)
{
my_upsampler_merge upsample = (my_upsampler_merge)cinfo.upsample;
try
{
upsample.Cr_r_tab = new int[MAXJSAMPLE + 1];
upsample.Cb_b_tab = new int[MAXJSAMPLE + 1];
upsample.Cr_g_tab = new int[MAXJSAMPLE + 1];
upsample.Cb_g_tab = new int[MAXJSAMPLE + 1];
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
for (int i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++)
{
// i is the actual input pixel value, in the range 0..MAXJSAMPLE
// The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE
// Cr=>R value is nearest int to 1.40200 * x
upsample.Cr_r_tab[i] = (int)((FIX_140200 * x + ONE_HALF) >> SCALEBITS);
// Cb=>B value is nearest int to 1.77200 * x
upsample.Cb_b_tab[i] = (int)((FIX_177200 * x + ONE_HALF) >> SCALEBITS);
// Cr=>G value is scaled-up -0.71414 * x
upsample.Cr_g_tab[i] = (-FIX_071414) * x;
// Cb=>G value is scaled-up -0.34414 * x
// We also add in ONE_HALF so that need not do it in inner loop
upsample.Cb_g_tab[i] = (-FIX_034414) * x + ONE_HALF;
}
}
// Control routine to do upsampling (and color conversion).
//
// The control routine just handles the row buffering considerations.
// 2:1 vertical sampling case: may need a spare row.
static void merged_2v_upsample(jpeg_decompress cinfo, byte[][][] input_buf, ref uint in_row_group_ctr, uint in_row_groups_avail, byte[][] output_buf, uint output_buf_offset, ref uint out_row_ctr, uint out_rows_avail)
{
my_upsampler_merge upsample = (my_upsampler_merge)cinfo.upsample;
byte[][] work_ptrs = new byte[2][];
uint num_rows; // number of rows returned to caller
if (upsample.spare_full)
{
// If we have a spare row saved from a previous cycle, just return it.
Array.Copy(upsample.spare_row, output_buf[output_buf_offset + out_row_ctr], upsample.out_row_width);
num_rows = 1;
upsample.spare_full = false;
}
else
{
// Figure number of rows to return to caller.
num_rows = 2;
// Not more than the distance to the end of the image.
if (num_rows > upsample.rows_to_go)
{
num_rows = upsample.rows_to_go;
}
// And not more than what the client can accept:
out_rows_avail -= out_row_ctr;
if (num_rows > out_rows_avail)
{
num_rows = out_rows_avail;
}
// Create output pointer array for upsampler.
work_ptrs[0] = output_buf[output_buf_offset + out_row_ctr];
if (num_rows > 1)
{
work_ptrs[1] = output_buf[output_buf_offset + out_row_ctr + 1];
}
else
{
work_ptrs[1] = upsample.spare_row;
upsample.spare_full = true;
}
// Now do the upsampling.
upsample.upmethod(cinfo, input_buf, in_row_group_ctr, work_ptrs, 0);
}
// Adjust counts
out_row_ctr += num_rows;
upsample.rows_to_go -= num_rows;
// When the buffer is emptied, declare this input row group consumed
if (!upsample.spare_full)
{
in_row_group_ctr++;
}
}
// Initialize for an upsampling pass.
static void start_pass_merged_upsample(jpeg_decompress cinfo)
{
my_upsampler_merge upsample = (my_upsampler_merge)cinfo.upsample;
// Mark the spare buffer empty
upsample.spare_full = false;
// Initialize total-height counter for detecting bottom of image
upsample.rows_to_go = cinfo.output_height;
}
// These are the routines invoked by the control routines to do
// the actual upsampling/conversion. One row group is processed per call.
//
// Note: since we may be writing directly into application-supplied buffers,
// we have to be honest about the output width; we can't assume the buffer
// has been rounded up to an even width.
// Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
static void h2v1_merged_upsample(jpeg_decompress cinfo, byte[][][] input_buf, uint in_row_group_ctr, byte[][] output_buf, int output_buf_offset)
{
my_upsampler_merge upsample = (my_upsampler_merge)cinfo.upsample;
// copy these pointers into registers if possible
int[] Crrtab = upsample.Cr_r_tab;
int[] Cbbtab = upsample.Cb_b_tab;
int[] Crgtab = upsample.Cr_g_tab;
int[] Cbgtab = upsample.Cb_g_tab;
byte[] inptr0 = input_buf[0][in_row_group_ctr];
byte[] inptr1 = input_buf[1][in_row_group_ctr];
byte[] inptr2 = input_buf[2][in_row_group_ctr];
byte[] outptr = output_buf[output_buf_offset];
int inptr0_ind = 0, inptrX_ind = 0, outptr_ind = 0;
// Loop for each pair of output pixels
for (uint col = cinfo.output_width >> 1; col > 0; col--)
{
// Do the chroma part of the calculation
int cb = inptr1[inptrX_ind];
int cr = inptr2[inptrX_ind];
inptrX_ind++;
int cred = Crrtab[cr];
int cgreen = (int)((Cbgtab[cb] + Crgtab[cr]) >> SCALEBITS);
int cblue = Cbbtab[cb];
// Fetch 2 Y values and emit 2 pixels
int y = inptr0[inptr0_ind++];
int tmp = y + cred; outptr[outptr_ind + RGB_RED] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
tmp = y + cgreen; outptr[outptr_ind + RGB_GREEN] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
tmp = y + cblue; outptr[outptr_ind + RGB_BLUE] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
outptr_ind += RGB_PIXELSIZE;
y = inptr0[inptr0_ind++];
tmp = y + cred; outptr[outptr_ind + RGB_RED] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
tmp = y + cgreen; outptr[outptr_ind + RGB_GREEN] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
tmp = y + cblue; outptr[outptr_ind + RGB_BLUE] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
outptr_ind = RGB_PIXELSIZE;
}
// If image width is odd, do the last output column separately
if ((cinfo.output_width & 1) != 0)
{
int cb = inptr1[inptrX_ind];
int cr = inptr2[inptrX_ind];
int cred = Crrtab[cr];
int cgreen = (int)((Cbgtab[cb] + Crgtab[cr]) >> SCALEBITS);
int cblue = Cbbtab[cb];
int y = inptr0[inptr0_ind];
int tmp = y + cred; outptr[outptr_ind + RGB_RED] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
tmp = y + cgreen; outptr[outptr_ind + RGB_GREEN] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
tmp = y + cblue; outptr[outptr_ind + RGB_BLUE] = (byte)(tmp >= MAXJSAMPLE?MAXJSAMPLE:(tmp < 0?0:tmp));
}
}
// 1:1 vertical sampling case: much easier, never need a spare row.
static void merged_1v_upsample(jpeg_decompress cinfo, byte[][][] input_buf, ref uint in_row_group_ctr, uint in_row_groups_avail, byte[][] output_buf, uint output_buf_offset, ref uint out_row_ctr, uint out_rows_avail)
{
my_upsampler_merge upsample = (my_upsampler_merge)cinfo.upsample;
// Just do the upsampling.
upsample.upmethod(cinfo, input_buf, in_row_group_ctr, output_buf, (int)(output_buf_offset + out_row_ctr));
// Adjust counts
out_row_ctr++;
in_row_group_ctr++;
}
// Module initialization routine for merged upsampling/color conversion.
//
// NB: this is called under the conditions determined by use_merged_upsample()
// in jdmaster.cs. That routine MUST correspond to the actual capabilities
// of this module; no safety checks are made here.
public static void jinit_merged_upsampler(jpeg_decompress cinfo)
{
my_upsampler_merge upsample = null;
try
{
upsample = new my_upsampler_merge();
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
cinfo.upsample = upsample;
upsample.start_pass = start_pass_merged_upsample;
#if UPSCALING_CONTEXT
upsample.need_context_rows = false;
#endif
upsample.out_row_width = (uint)(cinfo.output_width * cinfo.out_color_components);
if (cinfo.max_v_samp_factor == 2)
{
upsample.upsample = merged_2v_upsample;
upsample.upmethod = h2v2_merged_upsample;
// Allocate a spare row buffer
try
{
upsample.spare_row = new byte[upsample.out_row_width];
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
}
else
{
upsample.upsample = merged_1v_upsample;
upsample.upmethod = h2v1_merged_upsample;
// No spare row needed
upsample.spare_row = null;
}
build_ycc_rgb_table_upsample(cinfo);
}
// Module initialization routine for merged upsampling/color conversion.
//
// NB: this is called under the conditions determined by use_merged_upsample()
// in jdmaster.cs. That routine MUST correspond to the actual capabilities
// of this module; no safety checks are made here.
public static void jinit_merged_upsampler(jpeg_decompress cinfo)
{
my_upsampler_merge upsample=null;
try
{
upsample=new my_upsampler_merge();
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
cinfo.upsample=upsample;
upsample.start_pass=start_pass_merged_upsample;
#if UPSCALING_CONTEXT
upsample.need_context_rows=false;
#endif
upsample.out_row_width=(uint)(cinfo.output_width*cinfo.out_color_components);
if(cinfo.max_v_samp_factor==2)
{
upsample.upsample=merged_2v_upsample;
upsample.upmethod=h2v2_merged_upsample;
// Allocate a spare row buffer
try
{
upsample.spare_row=new byte[upsample.out_row_width];
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
}
else
{
upsample.upsample=merged_1v_upsample;
upsample.upmethod=h2v1_merged_upsample;
// No spare row needed
upsample.spare_row=null;
}
build_ycc_rgb_table_upsample(cinfo);
}
