// Set up the scan parameters for the current scan
static void select_scan_parameters(jpeg_compress cinfo)
{
#if NEED_SCAN_SCRIPT
if (cinfo.scan_info != null)
{
// Prepare for current scan --- the script is already validated
my_comp_master master = (my_comp_master)cinfo.master;
jpeg_scan_info scanptr = cinfo.scan_info[master.scan_number];
cinfo.comps_in_scan = scanptr.comps_in_scan;
for (int ci = 0; ci < scanptr.comps_in_scan; ci++)
{
cinfo.cur_comp_info[ci] = cinfo.comp_info[scanptr.component_index[ci]];
}
cinfo.Ss = scanptr.Ss;
cinfo.Se = scanptr.Se;
cinfo.Ah = scanptr.Ah;
cinfo.Al = scanptr.Al;
}
else
#endif
{
// Prepare for single sequential-JPEG scan containing all components
if (cinfo.num_components > MAX_COMPS_IN_SCAN)
{
ERREXIT2(cinfo, J_MESSAGE_CODE.JERR_COMPONENT_COUNT, cinfo.num_components, MAX_COMPS_IN_SCAN);
}
cinfo.comps_in_scan = cinfo.num_components;
for (int ci = 0; ci < cinfo.num_components; ci++)
{
cinfo.cur_comp_info[ci] = cinfo.comp_info[ci];
}
if (cinfo.lossless)
{
#if C_LOSSLESS_SUPPORTED
// If we fall through to here, the user specified lossless, but did not
// provide a scan script.
ERREXIT(cinfo, J_MESSAGE_CODE.JERR_NO_LOSSLESS_SCRIPT);
#endif
}
else
{
cinfo.process = J_CODEC_PROCESS.JPROC_SEQUENTIAL;
cinfo.Ss = 0;
cinfo.Se = DCTSIZE2 - 1;
cinfo.Ah = 0;
cinfo.Al = 0;
}
}
}
// Finish up at end of pass.
static void finish_pass_master(jpeg_compress cinfo)
{
my_comp_master master = (my_comp_master)cinfo.master;
// The entropy coder always needs an end-of-pass call,
// either to analyze statistics or to flush its output buffer.
cinfo.coef.entropy_finish_pass(cinfo);
// Update state for next pass
switch (master.pass_type)
{
case c_pass_type.main_pass:
// next pass is either output of scan 0 (after optimization)
// or output of scan 1 (if no optimization).
master.pass_type = c_pass_type.output_pass;
if (!cinfo.optimize_coding)
{
master.scan_number++;
}
break;
case c_pass_type.huff_opt_pass:
// next pass is always output of current scan
master.pass_type = c_pass_type.output_pass;
break;
case c_pass_type.output_pass:
// next pass is either optimization or output of next scan
if (cinfo.optimize_coding)
{
master.pass_type = c_pass_type.huff_opt_pass;
}
master.scan_number++;
break;
}
master.pass_number++;
}
// Initialize master compression control.
static void jinit_c_master_control(jpeg_compress cinfo, bool transcode_only)
{
my_comp_master master=null;
try
{
master=new my_comp_master();
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
cinfo.master=master;
master.prepare_for_pass=prepare_for_pass;
master.pass_startup=pass_startup;
master.finish_pass=finish_pass_master;
master.is_last_pass=false;
cinfo.DCT_size=cinfo.lossless?1:(uint)DCTSIZE;
// Validate parameters, determine derived values
initial_setup(cinfo);
if(cinfo.scan_info!=null)
{
#if NEED_SCAN_SCRIPT
validate_script(cinfo);
#else
ERREXIT(cinfo, J_MESSAGE_CODE.JERR_NOT_COMPILED);
#endif
}
else
{
cinfo.process=J_CODEC_PROCESS.JPROC_SEQUENTIAL;
cinfo.num_scans=1;
}
if((cinfo.process==J_CODEC_PROCESS.JPROC_PROGRESSIVE||cinfo.process==J_CODEC_PROCESS.JPROC_LOSSLESS)&&!cinfo.arith_code)
cinfo.optimize_coding=true; // assume default tables no good for progressive mode or lossless mode; but only in Huffman case!
// Initialize my private state
if(transcode_only)
{ // no main pass in transcoding
if(cinfo.optimize_coding) master.pass_type=c_pass_type.huff_opt_pass;
else master.pass_type=c_pass_type.output_pass;
}
else
{ // for normal compression, first pass is always this type:
master.pass_type=c_pass_type.main_pass;
}
master.scan_number=master.pass_number=0;
if(cinfo.optimize_coding) master.total_passes=cinfo.num_scans*2;
else master.total_passes=cinfo.num_scans;
}
// Initialize master compression control.
static void jinit_c_master_control(jpeg_compress cinfo, bool transcode_only)
{
my_comp_master master = null;
try
{
master = new my_comp_master();
}
catch
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_OUT_OF_MEMORY, 4);
}
cinfo.master = master;
master.prepare_for_pass = prepare_for_pass;
master.pass_startup = pass_startup;
master.finish_pass = finish_pass_master;
master.is_last_pass = false;
cinfo.DCT_size = cinfo.lossless?1:(uint)DCTSIZE;
// Validate parameters, determine derived values
initial_setup(cinfo);
if (cinfo.scan_info != null)
{
#if NEED_SCAN_SCRIPT
validate_script(cinfo);
#else
ERREXIT(cinfo, J_MESSAGE_CODE.JERR_NOT_COMPILED);
#endif
}
else
{
cinfo.process = J_CODEC_PROCESS.JPROC_SEQUENTIAL;
cinfo.num_scans = 1;
}
if ((cinfo.process == J_CODEC_PROCESS.JPROC_PROGRESSIVE || cinfo.process == J_CODEC_PROCESS.JPROC_LOSSLESS) && !cinfo.arith_code)
{
cinfo.optimize_coding = true; // assume default tables no good for progressive mode or lossless mode; but only in Huffman case!
}
// Initialize my private state
if (transcode_only)
{ // no main pass in transcoding
if (cinfo.optimize_coding)
{
master.pass_type = c_pass_type.huff_opt_pass;
}
else
{
master.pass_type = c_pass_type.output_pass;
}
}
else
{ // for normal compression, first pass is always this type:
master.pass_type = c_pass_type.main_pass;
}
master.scan_number = master.pass_number = 0;
if (cinfo.optimize_coding)
{
master.total_passes = cinfo.num_scans * 2;
}
else
{
master.total_passes = cinfo.num_scans;
}
}
// Per-pass setup.
// This is called at the beginning of each pass. We determine which modules
// will be active during this pass and give them appropriate start_pass calls.
// We also set is_last_pass to indicate whether any more passes will be required.
static void prepare_for_pass(jpeg_compress cinfo)
{
my_comp_master master = (my_comp_master)cinfo.master;
switch (master.pass_type)
{
case c_pass_type.main_pass:
// Initial pass: will collect input data, and do either Huffman
// optimization or data output for the first scan.
select_scan_parameters(cinfo);
per_scan_setup(cinfo);
if (!cinfo.raw_data_in)
{
cinfo.cconvert.start_pass(cinfo);
cinfo.downsample.start_pass(cinfo);
cinfo.prep.start_pass(cinfo, J_BUF_MODE.JBUF_PASS_THRU);
}
cinfo.coef.entropy_start_pass(cinfo, cinfo.optimize_coding);
cinfo.coef.start_pass(cinfo, (master.total_passes > 1?J_BUF_MODE.JBUF_SAVE_AND_PASS:J_BUF_MODE.JBUF_PASS_THRU));
cinfo.main.start_pass(cinfo, J_BUF_MODE.JBUF_PASS_THRU);
if (cinfo.optimize_coding)
{
// No immediate data output; postpone writing frame/scan headers
master.call_pass_startup = false;
}
else
{
// Will write frame/scan headers at first jpeg_write_scanlines call
master.call_pass_startup = true;
}
break;
#if ENTROPY_OPT_SUPPORTED
case c_pass_type.huff_opt_pass:
// Do Huffman optimization for a scan after the first one.
select_scan_parameters(cinfo);
per_scan_setup(cinfo);
if (cinfo.coef.need_optimization_pass(cinfo))
{
cinfo.coef.entropy_start_pass(cinfo, true);
cinfo.coef.start_pass(cinfo, J_BUF_MODE.JBUF_CRANK_DEST);
master.call_pass_startup = false;
break;
}
// Special case: Huffman DC refinement scans need no Huffman table
// and therefore we can skip the optimization pass for them.
master.pass_type = c_pass_type.output_pass;
master.pass_number++;
goto case c_pass_type.output_pass; // FALLTHROUGH
#endif
case c_pass_type.output_pass:
// Do a data-output pass.
// We need not repeat per-scan setup if prior optimization pass did it.
if (!cinfo.optimize_coding)
{
select_scan_parameters(cinfo);
per_scan_setup(cinfo);
}
cinfo.coef.entropy_start_pass(cinfo, false);
cinfo.coef.start_pass(cinfo, J_BUF_MODE.JBUF_CRANK_DEST);
// We emit frame/scan headers now
if (master.scan_number == 0)
{
cinfo.marker.write_frame_header(cinfo);
}
cinfo.marker.write_scan_header(cinfo);
master.call_pass_startup = false;
break;
default: ERREXIT(cinfo, J_MESSAGE_CODE.JERR_NOT_COMPILED); break;
}
master.is_last_pass = (master.pass_number == master.total_passes - 1);
// Set up progress monitor's pass info if present
if (cinfo.progress != null)
{
cinfo.progress.completed_passes = master.pass_number;
cinfo.progress.total_passes = master.total_passes;
}
}
