[tex-live] [pdftex] PDF 1.5 by default in TL 2010

[Thierry Bouche]

Le mercredi 13 janvier 2010 à 12:14:54, Manuel écrivit :

MPG> Philip TAYLOR a écrit :

>> Yes, I could install a more recent version of Acrobat Reader;
>> however, there are real advantages in using Adobe Acrobat (as
>> opposed to Reader) but the cost of upgrading to (say)
>> AA Professional Extended 9 is way beyond my reach :-(
>> 
MPG> Sure, but then you could stay with TL09, or install a free viewer just for
MPG> viewing while keeping AA for the rest,

Not on the same machine! installing newer versions of AR implies
uninstalling old versions even of AA (if I understood correctly the
acronyms used by Phil...). Acrobat 5 was a really good, reliable, and
affordable (especially if you're in education) piece of software.
Moreover, you had free plug-ins by e.g. Enfocus (or commercial
extensions by the same): I am sure that in many workflows,
professional or not, keeping AA 5 has been preferred to an endless
upgrading (thus plug-ins as well, etc.).

Anyway, this is really a tiny detail. What is less tiny is the content
of the files distributed. In PDF 1.4, the internal structure of the
PDF tree is more or less transparent, so that any viewer supporting
PDF 1.0 can understand the file and display what it supports (the HTML
viewer philosophy, more or less), and just leave apart some objects
that are not understood. If you have so many annotations and objects
that this structure represents heavy weight overheads, then you could
just gzip your PDF file that would still be compatible with the
world. (Maybe not elegant, but efficient). If you produce a PDF file
where all this structure (which is verbose text) is compressed, then
the content of the file is just inaccessible to any third party parser
which has not been updated for PDF 1.5 (remember that people might be
interested not only in viewing or printing PDF, but also reading it
aloud for blind people, extracting metadata, converting textual
content to some XML dialect: it's not only acrobat replacements whose
compatibility have to be evaluated before such a move!).

It is funny to observe that while the trend for the ubiquitous format
like XML (do you see a strong demand for compressed SVG?) is to have
hyper-verbose uncompressed representation of content, we should care
so much about the size of PDF files. I've been told that most text
file transfer over the networks are compressed on the fly by the
routers (?) so that the actual impact on bandwidth might be zero.

 Thierry