[pdftex] Reducing the number of font descriptors (was: Font subsetting with PDFs from InDesign?)

[Thanh Han The]

On Fri, Jul 11, 2008 at 2:57 PM, Martin Schröder <martin at oneiros.de> wrote:
> 2008/7/11 Thanh Han The <hanthethanh at gmail.com>:
>> On Fri, Jul 11, 2008 at 2:22 PM, Martin Schröder <martin at oneiros.de> wrote:
>>> And the conclusion was: When including PDFs you always get a new font
>>> descriptor for every font in the PDFs.
>>
>> FWIW: it's the way pdftex does pdf inclusion since the very beginning.
>
> And everybody else (pdftk, Frame) does the same, it seems.
> How hard would it be to change that, i.e. to merge fonts? Or are there
> tools that already do this?

for pdftex it's rather difficult. If you want to merge font
descriptors, you must:

- make sure the encodings/charwidths/... are the same;
- decode page contents and parse them, and rename the font tags if
needed to avoid collision;
- maybe a few things more...

since it's hard to get this right, it's very unlikely pdftex will
support this, since we want pdf inclusion to be stable.

Thanh