[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

RE: Proposal: new fsfs.conf properties

From: Markus Schaber <m.schaber_at_codesys.com>
Date: Tue, 11 Jul 2017 12:53:45 +0000

Hi,

(Sorry, it seems my previous message was sent _very_ prematurely :-(

From: Pavel Lyalyakin [mailto:pavel.lyalyakin_at_visualsvn.com]
> Hello Paul,
>
> On Sat, Jul 8, 2017 at 2:51 AM, Paul Hammant <paul_at_hammant.org> wrote:
> >
> > 1. compression-exempt-suffixes = mp3,mp4,jpeg
> >
> > 2. deltification-exempt-suffixes = mp3,mp4,jpeg
> >
> > Regardless of the setting of 'compression-level', #1 above two mean certain
> things can skip the compression attempt. It must give up at a certain point
> right?
> >
> > Same for deltification re #2
> >
> > I'm assuming debate happens now. Then y'all let me go off and diligently
> file a Jira ticket for this feature request, or I slink away suitably
> admonished...
> >
> > - Paul
>
> I'm not sure whether this is going to be useful. How do you expect these
> exemptions to help Subversion users? What's the story?

I agree partly. Skipping compression for known "incompressible" formats like mpX, png or gif can come with performance benefits, saving some CPU cycles (see the recent performance disccussions on this list)

However, I'm not sure whether the same amounts for deltification. There are editing tasks which do not reencode the whole image / movie, and they can profit from deltification, for example:

- Lossless rotation / cropping of jpeg images.
- Editing / stripping the EXIF data of jpeg images.
- Embedding / dropping the preview thumbnail of jpeg images.
- Lossless MP3 editing (e. G. via mp3DirectCut).
- Editing MP3 meta data (e. G. Song Title)
(... and more...)

In all those cases, skipping deltification can drastically increase storage.

Best regards

Markus Schaber

CODESYS® a trademark of 3S-Smart Software Solutions GmbH

Inspiring Automation Solutions

3S-Smart Software Solutions GmbH
Dipl.-Inf. Markus Schaber | Product Development Core Technology
Memminger Str. 151 | 87439 Kempten | Germany
Tel. +49-831-54031-979 | Fax +49-831-54031-50

E-Mail: m.schaber@codesys.com | Web: http://www.codesys.com | CODESYS store: http://store.codesys.com
CODESYS forum: http://forum.codesys.com

Managing Directors: Dipl.Inf. Dieter Hess, Dipl.Inf. Manfred Werner | Trade register: Kempten HRB 6186 | Tax ID No.: DE 167014915

This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received
this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorised copying, disclosure
or distribution of the material in this e-mail is strictly forbidden.
Received on 2017-07-11 15:04:24 CEST

This is an archived mail posted to the Subversion Dev mailing list.