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

        private int emit_dqt(int index)
        {
            JQUANT_TBL qtbl = m_cinfo.m_quant_tbl_ptrs[index];
            if (qtbl == null)
                m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_NO_QUANT_TABLE, index);

            int prec = 0;
            for (int i = 0; i <= m_cinfo.lim_Se; i++)
            {
                if (qtbl.quantval[m_cinfo.natural_order[i]] > 255)
                    prec = 1;
            }

            if (!qtbl.Sent_table)
            {
                emit_marker(JPEG_MARKER.DQT);

                emit_2bytes(prec != 0 ?
                    m_cinfo.lim_Se * 2 + 2 + 1 + 2 : m_cinfo.lim_Se + 1 + 1 + 2);

                emit_byte(index + (prec << 4));

                for (int i = 0; i <= m_cinfo.lim_Se; i++)
                {
                    /* The table entries must be emitted in zigzag order. */
                    int qval = qtbl.quantval[m_cinfo.natural_order[i]];

                    if (prec != 0)
                        emit_byte(qval >> 8);

                    emit_byte(qval & 0xFF);
                }

                qtbl.Sent_table = true;
            }

            return prec;
        }