BitMiracle.LibJpeg.Classic.Internal.jpeg_marker_reader.get_sof C# (CSharp) Method

        private bool get_sof(bool is_baseline, bool is_prog, bool is_arith)
        {
            m_cinfo.is_baseline = is_baseline;
            m_cinfo.m_progressive_mode = is_prog;
            m_cinfo.arith_code = is_arith;

            int length;
            if (!m_cinfo.m_src.GetTwoBytes(out length))
                return false;

            if (!m_cinfo.m_src.GetByte(out m_cinfo.m_data_precision))
                return false;

            int temp = 0;
            if (!m_cinfo.m_src.GetTwoBytes(out temp))
                return false;
            m_cinfo.m_image_height = temp;

            if (!m_cinfo.m_src.GetTwoBytes(out temp))
                return false;
            m_cinfo.m_image_width = temp;

            if (!m_cinfo.m_src.GetByte(out m_cinfo.m_num_components))
                return false;

            length -= 8;

            m_cinfo.TRACEMS(1, J_MESSAGE_CODE.JTRC_SOF, m_cinfo.m_unread_marker,
                m_cinfo.m_image_width, m_cinfo.m_image_height, m_cinfo.m_num_components);

            if (m_cinfo.m_marker.m_saw_SOF)
                m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_SOF_DUPLICATE);

            /* We don't support files in which the image height is initially specified */
            /* as 0 and is later redefined by DNL.  As long as we have to check that,  */
            /* might as well have a general sanity check. */
            if (m_cinfo.m_image_height <= 0 || m_cinfo.m_image_width <= 0 || m_cinfo.m_num_components <= 0)
                m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_EMPTY_IMAGE);

            if (length != (m_cinfo.m_num_components * 3))
                m_cinfo.ERREXIT(J_MESSAGE_CODE.JERR_BAD_LENGTH);

            if (m_cinfo.Comp_info == null)
            {
                /* do only once, even if suspend */
                m_cinfo.Comp_info = jpeg_component_info.createArrayOfComponents(m_cinfo.m_num_components);
            }

            for (int ci = 0; ci < m_cinfo.m_num_components; ci++)
            {
                //jpeg_component_info compptr = m_cinfo.Comp_info[ci];

                int c;
                if (!m_cinfo.m_src.GetByte(out c))
                    return false;

                /* Check to see whether component id has already been seen   */
                /* (in violation of the spec, but unfortunately seen in some */
                /* files).  If so, create "fake" component id equal to the   */
                /* max id seen so far + 1. */
                int componentInfoIndex = 0;
                jpeg_component_info compptr = null;
                for (int i = 0; i < ci; i++, componentInfoIndex++)
                {
                    compptr = m_cinfo.Comp_info[componentInfoIndex];
                    if (c == compptr.Component_id)
                    {
                        componentInfoIndex = 0;
                        compptr = m_cinfo.Comp_info[componentInfoIndex];
                        c = compptr.Component_id;

                        componentInfoIndex++;
                        compptr = m_cinfo.Comp_info[componentInfoIndex];

                        for (i = 1; i < ci; i++, componentInfoIndex++)
                        {
                            compptr = m_cinfo.Comp_info[componentInfoIndex];
                            if (compptr.Component_id > c)
                                c = compptr.Component_id;
                        }

                        c++;
                        break;
                    }
                }

                compptr = m_cinfo.Comp_info[componentInfoIndex];
                compptr.Component_id = c;
                compptr.Component_index = ci;

                if (!m_cinfo.m_src.GetByte(out c))
                    return false;

                compptr.H_samp_factor = (c >> 4) & 15;
                compptr.V_samp_factor = (c) & 15;

                int quant_tbl_no;
                if (!m_cinfo.m_src.GetByte(out quant_tbl_no))
                    return false;

                compptr.Quant_tbl_no = quant_tbl_no;

                m_cinfo.TRACEMS(1, J_MESSAGE_CODE.JTRC_SOF_COMPONENT, compptr.Component_id,
                    compptr.H_samp_factor, compptr.V_samp_factor,
                    compptr.Quant_tbl_no);
            }

            m_cinfo.m_marker.m_saw_SOF = true;
            return true;
        }