[Doc-SIG] Issues with 2.1 doc PDF files

[Dinu Gherman]

Hi Fred,

ok, I did some investigation into that topic, basically some
comparisons of PDF files across different realeases. The pre-
liminary result is, maybe, quite interesting.

"Fred L. Drake, Jr." wrote:
> 
> Dinu Gherman writes:
>  >
>  > - file sizes are much bigger for 2.1 (50-100%)
> 
>   Yeah, I thought they looked a little large, but wasn't sure why.
> I've also noticed (and this isn't new) that the A4 versions are quite
> a bit larger than the US-Letter versions: about 50% for the PDF, not
> so much for the PostScript.  I have no idea why this would be the
> case.  I presume you were looking at the A4 version.

I think there shouldn't be any reason why this has to be like
that! In fact, if you compare a file like ref.pdf for 2.0 and
2.1 by listing the used fonts in Acrobat Reader via the menu
File -> Document Info -> Fonts you'll see that in the A4 ver-
sions the 2.1 file lists Helvetica, Helvetica-Oblique and
Times-Roman. But the 2.0 version lists a whole bunch of CM*
fonts which is TeX's ancient Computer Modern family. You can
actually *see* the difference if you sufficiently magnify, 
say, the document title on the front page and the version
number below it.

For me the reason why this 2.1 A4 version of ref.pdf is about
twice the size of the corresponding 2.0 file is that these
CM fonts are embedded in the PDF! 

The reason why this effect cannot be observed for the corres-
ponding PDF letter verions of the same document is that they 
both do not use embedded CM fonts! 

I haven't verified this for all other documents, but it seems
like a good reason to me explaining the general difference in
size between A4 and letter PDFs. Now, *why* the A4 files do
contain embedded fonts is an entirely different question! ;-)

>  > - fonts are approximated with pixelized bitmaps
> 
>   That's not good.

This is also an entirely different issue, as the tut.pdf in
A4 for 2.1 doesn't contain any normal fonts at all, but only
bitmaps as you can also find out doing the same research in 
Acrobat Reader!

>  > As a result you get:
>  >
>  > - much longer page building times in PDF readers
>  > - considerable longer search times
>  > - much longer print times (probably - haven't checked)
>  >
>  > I've not verified this for each PDF file (it's prominently
>  > obvious for the tutorial, though), but I assume the same
>  > effects can be observed for all of them, when comparing with
>  > corresponding files from the previous release.
> 
>   This would be something to look at -- recall that we added some
> magic to the tutorial to control interpretation of the document
> encoding, so that some Latin-1 characters would be typeset correctly.
> (This was at your prodding, as I recall!  ;-)  Could you please look
> at at least one of the other documents to see if they exhibit the same
> symptoms?

Apparently, the only line you added to do this is this one:

  \usepackage[T1]{fontenc}

which should do the job. I also use this:

  \usepackage[latin1]{inputenc}

but I just found out I can do without. In general I use this
line when running pdf(La)TeX over the sources:

\usepackage[pdftex,
  plainpages=false, 
  colorlinks=true, 
  bookmarks=true, 
  bookmarksnumbered=true,
  linkcolor=blue]{hyperref}

I haven't seen anything equivalent in the official LaTeX sources,
though, so I'm not quite sure how these are build...

>  > So, I'm really curious what the reason for this phenomenon
>  > could be? If there isn't any, I suggest reproducing the
>  > files to no longer show the described effects as they will
> 
>   If you can tell me how to control these things, I'm sure we can
> build another distribution.  I have no idea how to control this --
> this goes deeper into the LaTeX/pdfLaTeX magic than I'm familiar
> with.

Well, I can tell you what I do to create these documents on 
my box. I'm using vanilla MiKTeX 2 on Win2K, which gives me
the following version number for pdftex:

  C:\>pdftex
  This is pdfTeX, Version 3.14159-14f-released-20000525 (MiKTeX 2)
  **

Using this I get PDFs without any pixelized or mebedded fonts,
and without applying any additonal magic.

For all the offical PDF documentation files I've checked I get 
via File -> Document Info -> General this: pdfTeX-0.13d. Those 
that I'm producing myself say pdfTeX-0.14f. This might be a 
reason and it might be not - I don't know, probably not.

In any case something strange was going on when the A4 PDFs 
were produced (leading to embedded CM fonts) and something 
very strange happened for the 2.1 A4 PDF tutorial (bitmaps
throughout). BTW, the former (including file size differen-
ces) can be also observed on the official PS files.

This is about all I can do in a reasonable time frame to pro-
vide a good starting point for further research. I'm not con-
sidering myself a TeX guru or something like that, so I'll 
need to pass this on to somebody else here...

Regards,

Dinu