Re: Ghostscript/GhostPDL 9.22 Release Candidate 1

[Masamichi Hosoda]

>>If there is a full font embedded (non-subset) PDF,
>>does the bigpdfs trick work effectively?
> 
> Its still, in my opinion, a risky thing to do. However, if the font
> were fully embedded, you wouldn't need to use Ghostscript and the
> PDFDontUseFontObjectNum bug approach (which is the risky part).
> 
> Because the fonts would be genuinely identical, MuPDF would be able to
> spot the font streams at least as being the same and would be able to
> reliably remove the duplicates.
> 
> The Font and FontDescriptor dictionaries might not be possible to
> remove, so the effect wouldn't be quite as good as the current
> approach, but these dictionaries run to a few tens or at most a few
> hundred bytes. The FontFile streams are where most of the space is
> going, and those would be possible to remove, if they were truly
> duplicates.

I understand that the bigpdfs trick should to be fixed
to use MuPDF instead of PDFDontUseFontObjectNum bug.

>>Or, even so, should we take other methods (e.g. using non-embedded
>>PDFs)?
> 
> I'm not sure what other methods there would be. Using EPS inclusions
> would have the same effect as PDF. Rendering to bitmaps would be (I'd
> guess) as large as the PDF files, and would suffer from
> non-scalability.
> 
> Converting to TeX format would probably work, but apparently there
> were problems with that.
> 
> Is there some other approach available ?

There is a method of using font non-embedded PDF.
In my experiment, it seems to work fine except TrueType fonts.

It uses like
`-c ".setpdfwrite << /NeverEmbed [ /Emmentaler-20 /TeXGyreSchola-Regular ] >> 
setdistillerparams"`
instead of
`-sOutputFile=filename.pdf`.

I've made sample files `20170922_lilypond_eps_pdf_examples.tar.xz`.
https://drive.google.com/file/d/0ByGBX3PDrqjsSFhVdXJfbjFjRlk/view?usp=sharing

In the tarball:

`fonts?-bigpdfs.eps`: EPS that is generated by LilyPond.
`fonts?-bigpdfs-noembed.pdf`: No font embedded PDF
                              that is generated by Ghostscript
                              with `/NeverEmbed` parameter like above.
`include-bigpdfs-noembed.pdf`: TeX outputted PDF that lacks LilyPond fonts.
`include-bigpdfs-noembed-gse.pdf`: Finally PDF that is font embedded
                                   by Ghostscript.

In `include-bigpdfs-noembed-gse.pdf`,
OTF seems to be fine. However, some glyphs of TTF are broken.