dvd+rw-mediainfo does not return enough data on DVD-R

["Gene Cumm" <gene.cumm+deb@gmail.com>]

While trying to compare reviews on different DVD-R media at
http://www.videohelp.com/dvdmedia, I found that dvd+rw-mediainfo did
not return as much data as DVDInfoPro or DVDIdentifier when passing
more than one argument.  Running `dvd+rw-mediainfo /dev/dvdrw
<RANDOM_STRINGS>`, per the source code and miscellaneous posts
scattered across the web, returns a lot of debugging data.  When
dvd+rw-mediainfo returns the "media code", the equivalent to the ATIP
information for a DVD, it only returns 44 (4+40) bytes for a DVD-R[W].
 DVDInfoPro/DVDIdentifier return 48 bytes.  Some media actually has
data in those missing 4 bytes, including some Sonys I have.

Does anyone have an idea at what the "official" length of the media code is?