Bug 44643 - Difference in fractional font size handling in .ppt files, Impress vs. Powerpoint
Summary: Difference in fractional font size handling in .ppt files, Impress vs. Powerp...
Status: RESOLVED WORKSFORME
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Impress (show other bugs)
Version:
(earliest affected)
3.3.4 release
Hardware: All All
: lowest normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: Font-Rendering
  Show dependency treegraph
 
Reported: 2012-01-10 09:31 UTC by mathog
Modified: 2020-09-21 09:51 UTC (History)
3 users (show)

See Also:
Crash report or crash signature:


Attachments
example PDF with fractional font sizes (exported from Inkscape) (13.17 KB, application/pdf)
2012-01-10 09:31 UTC, mathog
Details
Image imported and saved to .ppt by LOImpress. (is .ppt, .zip is to allow upload) (31.50 KB, application/x-zip-compressed)
2012-01-10 09:32 UTC, mathog
Details
Screen dump of what the .ppt file looks like in Powerpoint (22.72 KB, image/png)
2012-01-10 09:33 UTC, mathog
Details

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Description mathog 2012-01-10 09:31:46 UTC
Created attachment 55386 [details]
example PDF with fractional font sizes (exported from Inkscape)

LO 3.4.4 release
MS PowerPoint 2003
Windows XP SP3

1.  Create a drawing with fractional font sizes (not integer points) in Inkscape, save as PDF.
2.  Import PDF in LODraw
3.  Copy drawing
4.  Paste drawing into LOImpress
5.  Save as .ppt file.

The resulting .ppt file has the following issues:

1.  In LOImpress the text looks as it did in the PDF but the font sizes are improperly displayed as whole integers when the text is selected.  That is, text
which is 12.8 points is said to be 13 points.

2.  When the .ppt file is opened in PowerPoint (2003) the font sizes are identified as the rounded to the nearest integer values AND they are also drawn that way.

Consequently, the resulting .ppt file does not look the same in Impress and PowerPoint.  

Clearly Impress is storing the fractional font sizes in the .ppt file somehow, but however it does this isn't being honored by PowerPoint.  Ideally the .ppt store would be done in such a way that Powerpoint can use the fractional font sizes.  Otherwise at least throw a (specific) warning.
Comment 1 mathog 2012-01-10 09:32:53 UTC
Created attachment 55387 [details]
Image imported and saved to .ppt by LOImpress. (is .ppt, .zip is to allow upload)
Comment 2 mathog 2012-01-10 09:33:42 UTC
Created attachment 55388 [details]
Screen dump of what the .ppt file looks like in Powerpoint

Note how the text now overflows the bounding rectangles.
Comment 3 mathog 2012-01-11 15:38:33 UTC
Tested this with 3.5.0b2 on Windows XP SP3.

The issue is still as previously described.

Tried saving in .pptx format.  Unfortunately for that one the bounding rectangles are lost.  They are initially there following:

draw
open PDF file
select all
copy

impress
paste
save as (pptx).

However, when Impress is closed and the .pptx reopened the bounding rectangles are gone.  Worse, the .pptx will not open in MS Powerpoint 2003 (with the 2007 compatibility pack).  This was the same with both 3.4.4 and 3.4.5b2.

On the plus side, if you can call it that, the fractional font sizes are retained in the .pptx format and shown that was in the font size area in LOImpress, both 3.4.4 and 3.4.5b2.

Tried opening the .pptx in PowerPoint 2010, but that version didn't like the .pptx file either.  PPT 2010 was able to open the .ppt file, and it looked exactly the same as it did in PPT 2003.
Comment 4 sasha.libreoffice 2012-05-07 07:50:16 UTC
Thanks for bugreport
reproduced that second attachment (rename from zip to ppt) looks differently in PP and in Impress. In Impress font size is slightly bigger. This often result in corrupted layout in presentations.
this tested in 3.3.4 and 3.5.3 on Fedora 64 bit

opening first attachment pdf in LO Draw:
in 3.5.3 difference is even more than in 3.3.4 (difference in Draw and pdf viewer)

Changing version to 3.3.4 as most early reproducible
Comment 5 nikos42 2013-11-08 21:23:39 UTC
Confirmed with LibreOffice 4.1.2.3
Comment 6 QA Administrators 2015-04-19 03:19:56 UTC Comment hidden (obsolete)
Comment 7 Buovjaga 2015-06-15 07:41:50 UTC
The font size looks ok now in .ppt, but the border and background color of the boxes is gone.

Win 7 Pro 64-bit Version: 5.1.0.0.alpha1+
Build ID: 01a189abcd9a4ca472a74b3b2c000c9338fc2c91
TinderBox: Win-x86@39, Branch:master, Time: 2015-06-14_07:46:28
Locale: fi-FI (fi_FI)
Comment 8 QA Administrators 2016-09-20 10:00:31 UTC Comment hidden (obsolete)
Comment 9 Timur 2018-04-19 11:35:00 UTC
In 6.1+ result is better than before as seen on screen dump.
Could be closed for this specific document but "fractional font size handling in .ppt files" general issue remains.
ODP is saved fine. PPT is saved by replacing Liberation to Arial. 
I don't see that "Impress is storing the fractional font sizes in the .ppt file somehow", even PPT opened in Impress has rounded font sizes.
Comment 10 QA Administrators 2019-09-29 03:07:54 UTC Comment hidden (obsolete)
Comment 11 Timur 2020-09-21 08:55:38 UTC
This is one of those forgotten bugs that are unlikely to be fixed, because now it's not clear what needs to be fixed.
The resulting .ppt file does look the same in Impress and PowerPoint.  
If you disagree, please test with current LO and write.
Comment 12 Buovjaga 2020-09-21 09:51:22 UTC
(In reply to Buovjaga from comment #7)
> The font size looks ok now in .ppt, but the border and background color of
> the boxes is gone.

Yeah, I don't see these issues anymore either

Arch Linux 64-bit
Version: 7.1.0.0.alpha0+
Build ID: 1f07c2e440326f2b2c8ffbb53c91570e6cfcd74d
CPU threads: 8; OS: Linux 5.8; UI render: default; VCL: kf5
Locale: fi-FI (fi_FI.UTF-8); UI: en-US
Calc: threaded
Built on 19 September 2020