Hello trid users,
some days ago i run TrID on newest zip based Corel CorelDRAW pattern
*.pat. All are described correctly as generic Zip document container by
zip-doc-cont.trid.xml. But they are misidentified as zipped CorelDRAW
drawing (*.cdr) by cdr-zip.trid.xml. ( see appended output/trid-v-old.txt).
The newest file(1) command describes such PAT examples as Corel Draw pattern
with version 22 ( see appended output/file-new.txt)
All such inspected Corel samples are zip containers, where first archive
member is an uncompressed file with 8 byte name mimetype. The
compression method 0 is expressed by XML construct like:
<Bytes>0000</Bytes>
<Pos>8</Pos>
This can be verified by looking in listing output of 7zip ( see appended
output/7z-l.txt)
This file contains the corresponding mime type. This starts for inspected
Corel samples with "application/x-vnd.corel.". So i run tridscan on samples
and delete null and garbage patterns and get definition file
pat-corel-22.trid.xml. The mime type ends with zcf.pattern+zip. This gives a
39 (27h) byte long mime type string for this zip variant. This is expressed
in pat-corel-22.trid.xml by XML construct like:
<Bytes>2700000027000000080000006D696D65747970656170706C69636174696F6E2F
<ASCII> ' . . . ' . . . . . . . m i m e t y p e a p p l i c a t i o n /
<Pos>18</Pos>
In other Corel ZIP based file formats, such scheme is used for version 17
and higher, but with CorelDraw 2020 only version 22 can be generated. So i
mention this fact in a remark line.
There exist no official information about that file format on Corel web
site. Some information about such patterns is found on file formats archive
website, but this information refers mainly to older RIFF based
variants. This is expressed by line:
<RefURL>
http://fileformats.archiveteam.org/wiki/CorelDRAW</RefURL>
The RIFF part is stored as a file with name "root.dat". This is expressed
inside pat-corel-22.trid.xml in global string section by line like:
<String>ROOT.DAT</String>
With the new definition the undetected CorelDRAW Pattern are now recognized
( see appended output/trid-new.txt). TrID definition, some examples and
output are stored in archive pat_zip.zip. I hope that my XML file can be
used in future version of triddefs.
There exist also some middle aged pattern variants, which are RIFF based.
These files are also not described correctly by TrID at the moment. I will
try to handle these files in a future session.
With best wishes
Jörg Jenderek
