private void WriteBuffer(int dataCount)
{
try
{
m_outfile.Write(m_buffer, 0, dataCount);
}
catch (IOException e)
{
m_cinfo.TraceMS(0, JMessageCode.JERR_FILE_WRITE, e.Message);
m_cinfo.ErrExit(JMessageCode.JERR_FILE_WRITE);
}
catch (NotSupportedException e)
{
m_cinfo.TraceMS(0, JMessageCode.JERR_FILE_WRITE, e.Message);
m_cinfo.ErrExit(JMessageCode.JERR_FILE_WRITE);
}
catch (ObjectDisposedException e)
{
m_cinfo.TraceMS(0, JMessageCode.JERR_FILE_WRITE, e.Message);
m_cinfo.ErrExit(JMessageCode.JERR_FILE_WRITE);
}
}
private readonly bool m_need_context_rows; /* true if need rows above & below */
public JpegDownsampler(JpegCompressStruct cinfo)
{
m_cinfo = cinfo;
m_need_context_rows = false;
if (cinfo.CIR601sampling)
{
cinfo.ErrExit(JMessageCode.JERR_CCIR601_NOTIMPL);
}
/* Verify we can handle the sampling factors, and set up method pointers */
var smoothok = true;
for (var ci = 0; ci < cinfo.m_num_components; ci++)
{
var componentInfo = cinfo.Component_info[ci];
/* Compute size of an "output group" for DCT scaling. This many samples
* are to be converted from max_h_samp_factor * max_v_samp_factor pixels.
*/
var h_out_group = (componentInfo.H_samp_factor * componentInfo.DCT_h_scaled_size) /
m_cinfo.min_DCT_h_scaled_size;
var v_out_group = (componentInfo.V_samp_factor * componentInfo.DCT_v_scaled_size) /
m_cinfo.min_DCT_v_scaled_size;
var h_in_group = m_cinfo.m_max_h_samp_factor;
var v_in_group = m_cinfo.m_max_v_samp_factor;
rowgroup_height[ci] = v_out_group; /* save for use later */
if (h_in_group == h_out_group && v_in_group == v_out_group)
{
if (cinfo.m_input_smoothing != 0)
{
m_downSamplers[ci] = DownSampleMethod.fullsize_smooth_downsampler;
m_need_context_rows = true;
}
else
{
m_downSamplers[ci] = DownSampleMethod.fullsize_downsampler;
}
}
else if (h_in_group == h_out_group * 2 && v_in_group == v_out_group)
{
smoothok = false;
m_downSamplers[ci] = DownSampleMethod.h2v1_downsampler;
}
else if (h_in_group == h_out_group * 2 && v_in_group == v_out_group * 2)
{
if (cinfo.m_input_smoothing != 0)
{
m_downSamplers[ci] = DownSampleMethod.h2v2_smooth_downsampler;
m_need_context_rows = true;
}
else
{
m_downSamplers[ci] = DownSampleMethod.h2v2_downsampler;
}
}
else if ((h_in_group % h_out_group) == 0 && (v_in_group % v_out_group) == 0)
{
smoothok = false;
m_downSamplers[ci] = DownSampleMethod.int_downsampler;
h_expand[ci] = (byte)(h_in_group / h_out_group);
v_expand[ci] = (byte)(v_in_group / v_out_group);
}
else
{
cinfo.ErrExit(JMessageCode.JERR_FRACT_SAMPLE_NOTIMPL);
}
}
if (cinfo.m_input_smoothing != 0 && !smoothok)
{
cinfo.TraceMS(0, JMessageCode.JTRC_SMOOTH_NOTIMPL);
}
}
/// <summary>
/// Write frame header.
/// This consists of DQT and SOFn markers,
/// a conditional LSE marker and a conditional pseudo SOS marker.
/// Note that we do not emit the SOF until we have emitted the DQT(s).
/// This avoids compatibility problems with incorrect implementations that
/// try to error-check the quant table numbers as soon as they see the SOF.
/// </summary>
public void WriteFrameHeader()
{
/* Emit DQT for each quantization table.
* Note that emit_dqt() suppresses any duplicate tables.
*/
var prec = 0;
for (var ci = 0; ci < m_cinfo.m_num_components; ci++)
{
prec += EmitDQT(m_cinfo.Component_info[ci].Quant_tbl_no);
}
/* now prec is nonzero iff there are any 16-bit quant tables. */
/* Check for a non-baseline specification.
* Note we assume that Huffman table numbers won't be changed later.
*/
bool is_baseline;
if (m_cinfo.arith_code ||
m_cinfo.m_progressive_mode ||
m_cinfo.m_data_precision != 8 ||
m_cinfo.BlockSize != JpegConstants.DCTSIZE)
{
is_baseline = false;
}
else
{
is_baseline = true;
for (var ci = 0; ci < m_cinfo.m_num_components; ci++)
{
if (m_cinfo.Component_info[ci].Dc_tbl_no > 1 || m_cinfo.Component_info[ci].Ac_tbl_no > 1)
{
is_baseline = false;
}
}
if (prec != 0 && is_baseline)
{
is_baseline = false;
/* If it's baseline except for quantizer size, warn the user */
m_cinfo.TraceMS(0, JMessageCode.JTRC_16BIT_TABLES);
}
}
/* Emit the proper SOF marker */
if (m_cinfo.arith_code)
{
if (m_cinfo.m_progressive_mode)
{
EmitSOF(JpegMarker.SOF10); /* SOF code for progressive arithmetic */
}
else
{
EmitSOF(JpegMarker.SOF9); /* SOF code for sequential arithmetic */
}
}
else if (m_cinfo.m_progressive_mode)
{
EmitSOF(JpegMarker.SOF2); /* SOF code for progressive Huffman */
}
else if (is_baseline)
{
EmitSOF(JpegMarker.SOF0); /* SOF code for baseline implementation */
}
else
{
EmitSOF(JpegMarker.SOF1); /* SOF code for non-baseline Huffman file */
}
/* Check to emit LSE inverse color transform specification marker */
if (m_cinfo.ColorTransform != JColorTransform.JCT_NONE)
{
EmitLseIct();
}
/* Check to emit pseudo SOS marker */
if (m_cinfo.m_progressive_mode && m_cinfo.BlockSize != JpegConstants.DCTSIZE)
{
EmitPseudoSOS();
}
}