// Do downsampling for a whole row group (all components).
// In this version we simply downsample each component independently.
static void sep_downsample(jpeg_compress cinfo, byte[][][] input_buf, uint in_row_index, byte[][][] output_buf, uint out_row_group_index)
{
my_downsampler downsample = (my_downsampler)cinfo.downsample;
for (int ci = 0; ci < cinfo.num_components; ci++)
{
downsample.methods[ci](cinfo, cinfo.comp_info[ci], input_buf[ci], in_row_index, output_buf[ci], (uint)(out_row_group_index * cinfo.comp_info[ci].v_samp_factor));
}
}
// Module initialization routine for downsampling.
// Note that we must select a routine for each component.
static void jinit_downsampler(jpeg_compress cinfo)
{
my_downsampler downsample = null;
try
{
downsample = new my_downsampler();
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
cinfo.downsample = downsample;
downsample.start_pass = start_pass_downsample;
downsample.downsample = sep_downsample;
downsample.need_context_rows = false;
if (cinfo.CCIR601_sampling)
{
ERREXIT(cinfo, J_MESSAGE_CODE.JERR_CCIR601_NOTIMPL);
}
bool smoothok = true;
// Verify we can handle the sampling factors, and set up method pointers
for (int ci = 0; ci < cinfo.num_components; ci++)
{
jpeg_component_info compptr = cinfo.comp_info[ci];
if (compptr.h_samp_factor == cinfo.max_h_samp_factor && compptr.v_samp_factor == cinfo.max_v_samp_factor)
{
#if INPUT_SMOOTHING_SUPPORTED
if (cinfo.smoothing_factor != 0)
{
downsample.methods[ci] = fullsize_smooth_downsample;
downsample.need_context_rows = true;
}
else
#endif
downsample.methods[ci] = fullsize_downsample;
}
else if (compptr.h_samp_factor * 2 == cinfo.max_h_samp_factor && compptr.v_samp_factor == cinfo.max_v_samp_factor)
{
smoothok = false;
downsample.methods[ci] = h2v1_downsample;
}
else if (compptr.h_samp_factor * 2 == cinfo.max_h_samp_factor && compptr.v_samp_factor * 2 == cinfo.max_v_samp_factor)
{
#if INPUT_SMOOTHING_SUPPORTED
if (cinfo.smoothing_factor != 0)
{
downsample.methods[ci] = h2v2_smooth_downsample;
downsample.need_context_rows = true;
}
else
#endif
downsample.methods[ci] = h2v2_downsample;
}
else if ((cinfo.max_h_samp_factor % compptr.h_samp_factor) == 0 && (cinfo.max_v_samp_factor % compptr.v_samp_factor) == 0)
{
smoothok = false;
downsample.methods[ci] = int_downsample;
}
else
{
ERREXIT(cinfo, J_MESSAGE_CODE.JERR_FRACT_SAMPLE_NOTIMPL);
}
}
#if INPUT_SMOOTHING_SUPPORTED
if (cinfo.smoothing_factor != 0 && !smoothok)
{
TRACEMS(cinfo, 0, J_MESSAGE_CODE.JTRC_SMOOTH_NOTIMPL);
}
#endif
}
// Module initialization routine for downsampling.
// Note that we must select a routine for each component.
static void jinit_downsampler(jpeg_compress cinfo)
{
my_downsampler downsample=null;
try
{
downsample=new my_downsampler();
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
cinfo.downsample=downsample;
downsample.start_pass=start_pass_downsample;
downsample.downsample=sep_downsample;
downsample.need_context_rows=false;
if(cinfo.CCIR601_sampling) ERREXIT(cinfo, J_MESSAGE_CODE.JERR_CCIR601_NOTIMPL);
bool smoothok=true;
// Verify we can handle the sampling factors, and set up method pointers
for(int ci=0; ci<cinfo.num_components; ci++)
{
jpeg_component_info compptr=cinfo.comp_info[ci];
if(compptr.h_samp_factor==cinfo.max_h_samp_factor&&compptr.v_samp_factor==cinfo.max_v_samp_factor)
{
#if INPUT_SMOOTHING_SUPPORTED
if(cinfo.smoothing_factor!=0)
{
downsample.methods[ci]=fullsize_smooth_downsample;
downsample.need_context_rows=true;
}
else
#endif
downsample.methods[ci]=fullsize_downsample;
}
else if(compptr.h_samp_factor*2==cinfo.max_h_samp_factor&&compptr.v_samp_factor==cinfo.max_v_samp_factor)
{
smoothok=false;
downsample.methods[ci]=h2v1_downsample;
}
else if(compptr.h_samp_factor*2==cinfo.max_h_samp_factor&&compptr.v_samp_factor*2==cinfo.max_v_samp_factor)
{
#if INPUT_SMOOTHING_SUPPORTED
if(cinfo.smoothing_factor!=0)
{
downsample.methods[ci]=h2v2_smooth_downsample;
downsample.need_context_rows=true;
}
else
#endif
downsample.methods[ci]=h2v2_downsample;
}
else if((cinfo.max_h_samp_factor%compptr.h_samp_factor)==0&&(cinfo.max_v_samp_factor%compptr.v_samp_factor)==0)
{
smoothok=false;
downsample.methods[ci]=int_downsample;
}
else ERREXIT(cinfo, J_MESSAGE_CODE.JERR_FRACT_SAMPLE_NOTIMPL);
}
#if INPUT_SMOOTHING_SUPPORTED
if(cinfo.smoothing_factor!=0&&!smoothok) TRACEMS(cinfo, 0, J_MESSAGE_CODE.JTRC_SMOOTH_NOTIMPL);
#endif
}
