DocBook documents are converted to Texinfo in two steps:
The DocBook source is converted by a XSLT stylesheet into an intermediate XML format, Texi-XML.
Texi-XML is simpler than DocBook and closer to the Texinfo format; it is intended to make the stylesheets’ job easier.
The stylesheet for this purpose is in xslt/texi/docbook.xsl. For portability, it should
always be referred to by the following URI:
http://docbook2x.sourceforge.net/latest/xslt/texi/docbook.xsl
Run this stylesheet with db2x_xsltproc.
Customizing. You can also customize the output by
creating your own XSLT stylesheet — changing parameters or
adding new templates — and importing xslt/texi/docbook.xsl.
Texi-XML is converted to the actual Texinfo files by db2x_texixml.
The docbook2texi command does both steps automatically, but if any problems occur, you can see the errors more clearly if you do each step separately:
$db2x_xsltproc -s teximydoc.xml -omydoc.txml$db2x_texixmlmydoc.txml
Options to the conversion stylesheet are described in the Texinfo stylesheets reference.