Re: Latest lilypond git master creating PDF 1.4 files instead of 1.7

[David Wright]

On Fri 10 Sep 2021 at 13:52:04 (-0700), H. S. Teoh wrote:
> On Fri, Sep 10, 2021 at 09:52:09PM +0200, Jean Abou Samra wrote:
> > Le 10/09/2021 à 19:09, H. S. Teoh a écrit :
> > > OK, I attached a contrived .ly file that produces 2 pages of music
> > > (the effect is most noticeable when there's more than 1 page), and
> > > two .pdf's, one compiled by the official Debian lilypond package
> > > (2.22.1), and one by my local lilypond build (latest git master).
> > > 
> > > The second file (test-bad.pdf) is noticeably slower to view on a PDF
> > > viewer; this is especially noticeable when flipping between pages.
> > > Whereas the first one (test-good.pdf) renders quickly and pages
> > > quickly.
> > 
> > What is your PDF reader? With all of Evince,
> > Okular and Firefox's built-in PDF reader on my
> > Ubuntu system, both files render fast enough and
> > I cannot see a noticeable difference.
> [...]
> 
> I'm using GV, which shows noticeably slowdown.  I tested again with
> Evince; the slowdown is still there but only in a more complex score.
> With the contrived score I posted it's not really noticeable. Also,
> Evince appears to cache generated pages at startup: with a more complex
> score there's a noticeable delay during startup, but thereafter about
> 2-3 pages are cached, and the delay only happens when you scroll to an
> uncached page.  With 2.22.1, there is no such slowdown.
> 
> Since PDF reader performance seems an unreliable measure of this issue,
> here's another one: running pdf2ps and then ps2pdf on the 2.22.1 score
> produces a compressed score (well, sometimes it doesn't compress well
> but the resulting file size is comparable to the original).  But on git
> master, both pdf2ps and ps2pdf take a very long time to run, and produce
> a .ps and second .pdf about 10x the size of the original file.
> 
> Something about the .pdf produced by (my build of) git master causes
> these tools to behave an in unusual way, and I want to find out why, and
> whether it's something caused by lilypond itself, or by some build
> misconfiguration on my part.

I've had a comment in my .bashrc file for years reminding me never to
use pdf2ps, but pdftops instead (comes with poppler). I think pdf2ps
might be suitable for the final rendering step in, say, CUPS.

I did run your test on test-good.pdf, using Debian buster:

109532 test-good.pdf →pdf2ps→  230847 good2.ps  →ps2pdf→ 28144 good2.pdf

109532 test-good.pdf →pdftops→ 100040 goodto.ps →ps2pdf→ 19427 goodto.pdf

2000% screenshots attached.

Cheers,
David.

test-good.png
Description: PNG image

good2.png
Description: PNG image

goodto.png
Description: PNG image