Extract XML from docx file with xproc 3.0 p:unarchive

Hi,

I have to convert a big amount of docx files into a specific XML format.

I wrote the XSLT that convert de myFile.docx!/word/document.xml after extracting it manually.

I'd like to use Xproc to loop on a full directory of docx fildes to extract each document.xml apply the xslt and validate the result.

After looping on each files of the directory i do :

<p:variable name="docx.uri" select="ancestor::c:directory/base-uri(.) || c:file/base-uri(.)"/>
<p:load href="{docx.uri}" name="load" content-type=" application/vnd.openxmlformats-officedocument.wordprocessingml.document "/>
<p:unarchive>
    <p:with-input>
      <p:pipe step="load" port="result"/>
    </p:with-input>
</p:unarchive>

At this point (p:unarchive) I get a XC0085 error : Error processing ZIP archive: zip END header not found
I tried different content-type like application/zip, but still have the same error.

Does that mean it's not possible to extract .docx archive juste like a zip archive ?
I was confident xproc could do that ?
Or did I missed something here ?

I'm using MorganaXProc-III 1.2.3

By the way most of the files I have are .doc not .docx, so if extraction has a solution from docx, I'll have to first convert them to docx (it seems there's a python script for it, I guess I can't do it from xproc ?)

Thanks in advance for your help,
Cheers,

Matthieu Ricaud-Dussarget