BitMiracle.LibJpeg.Classic.Internal.jpeg_marker_writer.write_frame_header C# (CSharp) Method

        public void write_frame_header()
        {
            /* Emit DQT for each quantization table.
             * Note that emit_dqt() suppresses any duplicate tables.
             */
            int prec = 0;
            for (int ci = 0; ci < m_cinfo.m_num_components; ci++)
                prec += emit_dqt(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.block_size != JpegConstants.DCTSIZE)
            {
                is_baseline = false;
            }
            else
            {
                is_baseline = true;
                for (int 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, J_MESSAGE_CODE.JTRC_16BIT_TABLES);
                }
            }

            /* Emit the proper SOF marker */
            if (m_cinfo.arith_code)
            {
                if (m_cinfo.m_progressive_mode)
                    emit_sof(JPEG_MARKER.SOF10); /* SOF code for progressive arithmetic */
                else
                    emit_sof(JPEG_MARKER.SOF9);  /* SOF code for sequential arithmetic */
            }
            else
            {
                if (m_cinfo.m_progressive_mode)
                    emit_sof(JPEG_MARKER.SOF2);    /* SOF code for progressive Huffman */
                else if (is_baseline)
                    emit_sof(JPEG_MARKER.SOF0);    /* SOF code for baseline implementation */
                else
                    emit_sof(JPEG_MARKER.SOF1);    /* SOF code for non-baseline Huffman file */
            }

            /* Check to emit LSE inverse color transform specification marker */
            if (m_cinfo.color_transform != J_COLOR_TRANSFORM.JCT_NONE)
                emit_lse_ict();

            /* Check to emit pseudo SOS marker */
            if (m_cinfo.m_progressive_mode && m_cinfo.block_size != JpegConstants.DCTSIZE)
                emit_pseudo_sos();
        }