I'm looking for a .NET library (preferably free/open source) or a command line tool to programmatically convert ordinary PDF (or PDF/A if that's easier) files to PDF/X-1a (2001 or 2003) for print processing.
Must be something that can be used locally (no web service or cloud) and run preferably under MS Windows.
I know that Aspose.Pdf can do this but would like to have more (also cheaper) possibilities to achieve this.
I will also try to convert via Ghostscript since I found a stackoverflow issue pointing to that possibility.
Any ideas?