3-Heights™ PDF to PDF/A Converter – create and sign a PDF/A from a PDF source

using System;
using Pdftools.Pdf2Pdf;
using Pdftools.Pdf;

namespace Pdf2PdfAConverterSamples
{
    class ConvertToPdfASample
    {
        /// <summary>
        /// Converts a given PDF document to PDF/A
        /// </summary>
        /// <param name="inFilePath">Path to PDF document to be converted</param>
        /// <param name="outFilePath">Path to resulting PDF/A</param>
        /// <param name="conformance">Conformance the converted file should conform to</param>
        /// <param name="allowDowngrade">Allow downgrade to another PDF/A level if requested conformance cannot be met</param>
        /// <param name="allowUpgrade">Allow upgrade to another PDF/A version if requested conformance cannot be met</param>
        public static void convertDocumentToPdfA(string inFilePath, string outFilePath, PDFConformance conformance, bool allowDowngrade, bool allowUpgrade, string outputIntent="", int errorMask=-1)
        {
            using (Pdf2Pdf conv = new Pdf2Pdf())
            {
                string logFilePath = outFilePath.Replace(".pdf", "") + "-log.txt";

                // 1. Configure the converter
                conv.Conformance = conformance;
                conv.AllowDowngrade = allowDowngrade;
                conv.AllowUpgrade = allowUpgrade;
                conv.ReportSummary = true;

                if (!string.IsNullOrWhiteSpace(outputIntent)) conv.OutputIntentProfile = outputIntent;
                if (errorMask >= 0) conv.ConversionErrorMask = errorMask;

                // 2. Convert document according to parameters set
                if (!conv.Convert(inFilePath, String.Empty, outFilePath, logFilePath))
                {
                    if (conv.ErrorCode == PDFErrorCode.PDF_E_CONVERSION)
                        printConversionErrors(conv.ConversionErrors);
                    else
                        Console.WriteLine(conv.ErrorCode + ": " + conv.ErrorMessage);

                    Console.WriteLine("See '" + logFilePath + "' for details.");
                }
            }
        }

        /// <summary>
        /// Prints given conversion errors
        /// </summary>
        /// <param name="conversionErrors">Encoded conversion error flags</param>
        public static void printConversionErrors(int conversionErrors)
        {
            Console.WriteLine("File converted to PDF/A, but conversion errors were encountered. Please check the resulting file manually.");
            Array errors = Enum.GetValues(typeof(PDFConversionError));
            foreach (PDFConversionError err in errors)
            {
                if (((int)err & conversionErrors) != 0)
                    Console.WriteLine("* " + err.ToString());
            }
        }
    }
}

pdf2pdf -v -rs -cl pdfa-2a in.pdf out.pdf
# Convert in.pdf to PDF/A-2a
# -v: verbose mode
# -rs: report summary
# -cl pdfa-2a: convert to PDF/A-2a

pdf2pdf -v -rs -cl pdfa-2a -ad in.pdf out.pdf
# Convert in.pdf to PDF/A-2a, but allow automatic downgrade of conformance level (to e.g. PDF/A-2b) if requested level cannot be met
# -ad: allow automatic downgrade

pdf2pdf -v -rs -cl pdfa-1b -au in.pdf out.pdf
# Convert in.pdf to PDF/A-1b, but allow automatic upgrade of PDF/A version, if target standard does not support certain elements of input document (e.g. from PDF/A-1 to PDF/A-2)
# -au: allow automatic upgrade