/// <summary>
/// Alternate compression function: just write an abbreviated table file.
/// </summary>
/// <remarks>Before calling this, all parameters and a data destination must be set up.<br/>
///
/// To produce a pair of files containing abbreviated tables and abbreviated
/// image data, one would proceed as follows:<br/>
///
/// <c>Initialize JPEG object<br/>
/// Set JPEG parameters<br/>
/// Set destination to table file<br/>
/// <see cref="jpeg_compress_struct.jpeg_write_tables">jpeg_write_tables();</see><br/>
/// Set destination to image file<br/>
/// <see cref="jpeg_compress_struct.jpeg_start_compress">jpeg_start_compress(false);</see><br/>
/// Write data...<br/>
/// <see cref="jpeg_compress_struct.jpeg_finish_compress">jpeg_finish_compress();</see><br/>
/// </c><br/>
///
/// jpeg_write_tables has the side effect of marking all tables written
/// (same as <see cref="jpeg_compress_struct.jpeg_suppress_tables">jpeg_suppress_tables(true)</see>).
/// Thus a subsequent <see cref="jpeg_compress_struct.jpeg_start_compress">jpeg_start_compress</see>
/// will not re-emit the tables unless it is passed <c>write_all_tables=true</c>.
/// </remarks>
public void jpeg_write_tables()
{
if (m_global_state != JpegState.CSTATE_START)
ERREXIT(J_MESSAGE_CODE.JERR_BAD_STATE, (int)m_global_state);
/* (Re)initialize error mgr and destination modules */
m_err.reset_error_mgr();
m_dest.init_destination();
/* Initialize the marker writer ... bit of a crock to do it here. */
m_marker = new jpeg_marker_writer(this);
/* Write them tables! */
m_marker.write_tables_only();
/* And clean up. */
m_dest.term_destination();
}
/// <summary>
/// Master selection of compression modules for transcoding.
/// </summary>
private void transencode_master_selection(jvirt_array<JBLOCK>[] coef_arrays)
{
/* Although we don't actually use input_components for transcoding,
* jcmaster.c's initial_setup will complain if input_components is 0.
*/
m_input_components = 1;
/* Initialize master control (includes parameter checking/processing) */
jinit_c_master_control(true /* transcode only */);
/* Entropy encoding: only Huffman coding supported. */
if (m_progressive_mode)
m_entropy = new phuff_entropy_encoder(this);
else
m_entropy = new huff_entropy_encoder(this);
/* We need a special coefficient buffer controller. */
m_coef = new my_trans_c_coef_controller(this, coef_arrays);
m_marker = new jpeg_marker_writer(this);
/* Write the datastream header (SOI, JFIF) immediately.
* Frame and scan headers are postponed till later.
* This lets application insert special markers after the SOI.
*/
m_marker.write_file_header();
}
/// <summary>
/// Master selection of compression modules for transcoding.
/// </summary>
private void transencode_master_selection(jvirt_array<JBLOCK>[] coef_arrays)
{
/* Initialize master control (includes parameter checking/processing) */
jinit_c_master_control(true /* transcode only */);
/* Entropy encoding: only Huffman or arithmetic coding. */
if (arith_code)
m_entropy = new arith_entropy_encoder(this);
else
m_entropy = new huff_entropy_encoder(this);
/* We need a special coefficient buffer controller. */
m_coef = new my_trans_c_coef_controller(this, coef_arrays);
m_marker = new jpeg_marker_writer(this);
/* Write the datastream header (SOI, JFIF) immediately.
* Frame and scan headers are postponed till later.
* This lets application insert special markers after the SOI.
*/
m_marker.write_file_header();
}
/// <summary>
/// Master selection of compression modules.
/// This is done once at the start of processing an image. We determine
/// which modules will be used and give them appropriate initialization calls.
/// This routine is in charge of selecting the modules to be executed and
/// making an initialization call to each one.
/// </summary>
private void jinit_compress_master()
{
/* Initialize master control (includes parameter checking/processing) */
jinit_c_master_control(false /* full compression */);
/* Preprocessing */
if (!m_raw_data_in)
{
m_cconvert = new jpeg_color_converter(this);
m_downsample = new jpeg_downsampler(this);
m_prep = new jpeg_c_prep_controller(this);
}
/* Forward DCT */
m_fdct = new jpeg_forward_dct(this);
/* Entropy encoding: only Huffman coding supported. */
if (m_progressive_mode)
m_entropy = new phuff_entropy_encoder(this);
else
m_entropy = new huff_entropy_encoder(this);
/* Need a full-image coefficient buffer in any multi-pass mode. */
m_coef = new my_c_coef_controller(this, (bool)(m_num_scans > 1 || m_optimize_coding));
jinit_c_main_controller(false /* never need full buffer here */);
m_marker = new jpeg_marker_writer(this);
/* Write the datastream header (SOI) immediately.
* Frame and scan headers are postponed till later.
* This lets application insert special markers after the SOI.
*/
m_marker.write_file_header();
}
/// <summary>
/// Master selection of compression modules.
/// This is done once at the start of processing an image. We determine
/// which modules will be used and give them appropriate initialization calls.
/// This routine is in charge of selecting the modules to be executed and
/// making an initialization call to each one.
/// </summary>
private void jinit_compress_master()
{
/* Sanity check on image dimensions */
if (m_image_height <= 0 || m_image_width <= 0 || m_input_components <= 0)
ERREXIT(J_MESSAGE_CODE.JERR_EMPTY_IMAGE);
/* Initialize master control (includes parameter checking/processing) */
jinit_c_master_control(false /* full compression */);
/* Preprocessing */
if (!m_raw_data_in)
{
m_cconvert = new jpeg_color_converter(this);
m_downsample = new jpeg_downsampler(this);
m_prep = new jpeg_c_prep_controller(this);
}
/* Forward DCT */
m_fdct = new jpeg_forward_dct(this);
/* Entropy encoding: either Huffman or arithmetic coding. */
if (arith_code)
m_entropy = new arith_entropy_encoder(this);
else
m_entropy = new huff_entropy_encoder(this);
/* Need a full-image coefficient buffer in any multi-pass mode. */
m_coef = new my_c_coef_controller(this, (bool)(m_num_scans > 1 || m_optimize_coding));
jinit_c_main_controller(false /* never need full buffer here */);
m_marker = new jpeg_marker_writer(this);
/* Write the datastream header (SOI) immediately.
* Frame and scan headers are postponed till later.
* This lets application insert special markers after the SOI.
*/
m_marker.write_file_header();
}
