private int m_scan_number; /* current index in scan_info[] */
public jpeg_comp_master(jpeg_compress_struct cinfo, bool transcode_only)
{
m_cinfo = cinfo;
if (transcode_only)
{
/* no main pass in transcoding */
if (cinfo.m_optimize_coding)
{
m_pass_type = c_pass_type.huff_opt_pass;
}
else
{
m_pass_type = c_pass_type.output_pass;
}
}
else
{
/* for normal compression, first pass is always this type: */
m_pass_type = c_pass_type.main_pass;
}
if (cinfo.m_optimize_coding)
{
m_total_passes = cinfo.m_num_scans * 2;
}
else
{
m_total_passes = cinfo.m_num_scans;
}
}
private bool prepare_for_huff_opt_pass()
{
/* Do Huffman optimization for a scan after the first one. */
select_scan_parameters();
per_scan_setup();
if (m_cinfo.m_Ss != 0 || m_cinfo.m_Ah == 0)
{
m_cinfo.m_entropy.start_pass(true);
m_cinfo.m_coef.start_pass(J_BUF_MODE.JBUF_CRANK_DEST);
m_call_pass_startup = false;
return(false);
}
/* Special case: Huffman DC refinement scans need no Huffman table
* and therefore we can skip the optimization pass for them.
*/
m_pass_type = c_pass_type.output_pass;
m_pass_number++;
return(true);
}
/// <summary>
/// Finish up at end of pass.
/// </summary>
public void finish_pass()
{
/* The entropy coder always needs an end-of-pass call,
* either to analyze statistics or to flush its output buffer.
*/
m_cinfo.m_entropy.finish_pass();
/* Update state for next pass */
switch (m_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).
*/
m_pass_type = c_pass_type.output_pass;
if (!m_cinfo.m_optimize_coding)
{
m_scan_number++;
}
break;
case c_pass_type.huff_opt_pass:
/* next pass is always output of current scan */
m_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 (m_cinfo.m_optimize_coding)
{
m_pass_type = c_pass_type.huff_opt_pass;
}
m_scan_number++;
break;
}
m_pass_number++;
}
private int m_scan_number; /* current index in scan_info[] */
public jpeg_comp_master(jpeg_compress_struct cinfo, bool transcode_only)
{
m_cinfo = cinfo;
if (transcode_only)
{
/* no main pass in transcoding */
if (cinfo.m_optimize_coding)
m_pass_type = c_pass_type.huff_opt_pass;
else
m_pass_type = c_pass_type.output_pass;
}
else
{
/* for normal compression, first pass is always this type: */
m_pass_type = c_pass_type.main_pass;
}
if (cinfo.m_optimize_coding)
m_total_passes = cinfo.m_num_scans * 2;
else
m_total_passes = cinfo.m_num_scans;
}
private bool prepare_for_huff_opt_pass()
{
/* Do Huffman optimization for a scan after the first one. */
select_scan_parameters();
per_scan_setup();
if (m_cinfo.m_Ss != 0 || m_cinfo.m_Ah == 0)
{
m_cinfo.m_entropy.start_pass(true);
m_cinfo.m_coef.start_pass(J_BUF_MODE.JBUF_CRANK_DEST);
m_call_pass_startup = false;
return false;
}
/* Special case: Huffman DC refinement scans need no Huffman table
* and therefore we can skip the optimization pass for them.
*/
m_pass_type = c_pass_type.output_pass;
m_pass_number++;
return true;
}
/// <summary>
/// Finish up at end of pass.
/// </summary>
public void finish_pass()
{
/* The entropy coder always needs an end-of-pass call,
* either to analyze statistics or to flush its output buffer.
*/
m_cinfo.m_entropy.finish_pass();
/* Update state for next pass */
switch (m_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).
*/
m_pass_type = c_pass_type.output_pass;
if (!m_cinfo.m_optimize_coding)
m_scan_number++;
break;
case c_pass_type.huff_opt_pass:
/* next pass is always output of current scan */
m_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 (m_cinfo.m_optimize_coding)
m_pass_type = c_pass_type.huff_opt_pass;
m_scan_number++;
break;
}
m_pass_number++;
}
