Bug 83448 - Add subsetting support for odf-embedded fonts
Summary: Add subsetting support for odf-embedded fonts
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: filters and storage (show other bugs)
(earliest affected)
Hardware: All All
: medium enhancement
Assignee: Not Assigned
Depends on:
Blocks: Fonts-Embedded
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Reported: 2014-09-03 17:52 UTC by Mingye Wang
Modified: 2019-02-22 13:00 UTC (History)
3 users (show)

See Also:
Crash report or crash signature:


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Description Mingye Wang 2014-09-03 17:52:58 UTC
As a user from China, I sometimes embed some CJK fonts like Source Han Sans in the odt files, and I always use multiple font weights at the same time. This causes the odt files to be extremely big, and takes some time to open. It seems that MS Office has such feature.

Btw, sometimes LibreOffice even embed some never-used fonts into the document. I found the names of the corresponding fonts in the xml files inside the ODT, but they are just some style information that are never used. LibreOffice is doing a bad job at this.

I am using LibreOffice on Windows 8.1. I guess it is a cross-platform problem. 

This bug report seems to be just an enhancement, but it is really important to the users of Pan-CJK fonts which often comes with a lot of glyphs.

If you need the file (~35MiB) to see what actually happened, just ask.
Comment 1 Joel Madero 2014-09-03 19:01:19 UTC
Please strip that file down as much as possible and then attach. You can only attach up to 10 megs so it'll have to be stripped down a bit.

Marking as NEEDINFO - once you get us a simple (really the simpler the better) test document mark the bug as UNCONFIRMED. Thanks
Comment 2 Adolfo Jayme Barrientos 2014-09-04 05:43:49 UTC
@Joel, I don’t think it’s necessary to ask the reporter to attach the font here, if you want to get it just google it and download it, it’s free. ;-)

I am marking this NEW because it’s a valid enhancement request and I am familiar with the MS Office feature Arthur mentions, which is called “font subsetting”, that is indeed missing from LibreOffice.
Comment 3 Mingye Wang 2016-05-05 17:43:51 UTC
I guess this should be a storage or Base feature instead.
Comment 4 Mingye Wang 2017-10-13 01:20:43 UTC
LibreOffice's PDF part seems to do the font subsetting part well. Any chance for taking those things for ODF files?
Comment 5 Mingye Wang 2018-02-19 22:07:52 UTC
Ah. There are quite a few flavors of CreateFontSubset lying around, sorted by what platform mechanisms they can use. The Windows one unsurprisingly supports TTF only just like MSO does...