Category Archives: Linux Stuff

Linux Stuff

Diagramming with bling: VRT updates free stencils for LibreOffice

Annoyed with much dated networking stencils in free diagramming software? Mark Oellermann of VRT, an Australian systems integration company, fixed that for you.

The situation with diagramming stencils for free software is no less frustrating that the situation with the actual diagramming software. If you do a lot of this kind of technical illustrations in your line of work, chances are you either use Visio-like proprietary software, clench your teeth, shut down your sense of beauty and get on with Dia’s set of shapes, or maybe ransack Open Clip Art Library for anything usable.

Strictly speaking, diagramming is about getting the job done. However, the bling does help selling projects to customers. And that’s where Mark’s contribution to LibreOffice is so important.

The collection he designed contains 200+ stencils in light and dark variants: routers, server racks, printers, desktops, laptops, IP phones — pretty much everything you need, if you are in the systems integration business, or if you are responsible for IT infrastructure in your company. It doesn’t exactly bring the art of flowcharting to the next level, but it does provide a sensible alternative.

Network shapescollection

Over to Mark:

I work for a small company that moved to LibreOffice and needed to create the sorts of IT networking diagrams you often see done with Visio’s isometric shapes, but couldn’t find any decent shape libraries in a suitable open format.

After much investigation I realised that it wouldn’t be too hard to produce something ourselves on par with what MS had done for Visio, so I dived in and some 2 years later we’ve got near 200 symbols, available on CC terms.

The project is not exactly news: the first collection was released over two years ago, but for some inexplicable reason it barely got public’s attention at all. The most recent version of the stencils collection was released last week and features newly added shapes for logical networking and visualisation/display systems.

Stencils can be installed as both and LibreOffice extensions.

Later this year Mark expects to ships the stencils in SVG and PNG, so that once Inkscape 0.91 is out, people could easily plug new shapes and use them (the upcoming release is featuring a Symbols palette), or easily convert them to Dia shapes.

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Explore new ideas with latest Distrho’s softsynths

Do you feel like you could do with more virtual instruments and sound FX plugins on Linux? Filipe Coelho released new ports of synths that are based on Yamaha DX7, Oberheim OB-X, and Roland TB-303.

The Ports section of the Distrho project is essentially comprised of native ports of plugins that had been released by their developers on KVR or elsewhere as free software. Pretty much all of those plugins were developed with the JUCE crossplatform multimedia framework which makes Filipe’s job a lot easier.

This section now contains 3 new software synthesizers and 3 new audio effects:

  • Dexed — a softsynth based on Yamaha DX7. It might look simple, but it’s versatile enough to produce a variety of sounds, from ethereal pads to weird sounds effects.
  • Nekobi — a softsynth that is loosely based around Roland TB-303. This might come in handy to those who have been composing in Ardour 3 and missing an LV2/VST version of the DSSI-based counterpart called Nekobee.
  • Obxd — another synth based on a real piece of hardware, this time — Oberheim OB-X. Vadim Filatov, original developer of the plugin, also participated in development of Dexed.
  • KlangFalter — a convolution reverb that supports true stereo impulse response files and loads them in their entirety while managing to keep the DSP load low enough (at least, that’s the claim).
  • MVerb — a reverb that provides a much anticipated free implementation of Jon Dattorro’s figure-of-eight topology of the feedback loop (see the paper for details). A Linux VST build of the plugin was provided by the original developer, Martin Eastwood. Filipe provided the LV2 version of the reverb effect.
  • Pitched Delay — a basic delay effect that can optionally pitch-correct the sound both inside and outside the feedback loop.

All plugins are available as LV2 and native Linux VST effects supported by e.g. Ardour and Qtractor digital audio workstations. Source code is up on GitHub, same as the issue tracker.

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Tupi project goes to Indiegogo, asks for funding of a Windows port

Gustav Gonzalez launched a fundraiser to create a Windows port of Tupi, a free exposure sheet based animation editor with tweening tools and a stopmotion plugin.

Tupi is essentially a one-man band project, so it’s going to take a while till it can be safely recommended for use on deadlines in production pipelines. However evidence suggests that the app turned out to be easy enough for kids around the world to learn the basics of animation.

Since neither Linux nor OSX dominate on the educational market, bringing Tupi to even more kids at schools simply means porting the animation editor to Windows.

Gustav estimated the project cost as USD $6000 which includes Indiegogo processing fee, development time for a month of work, a new laptop for development, annual hosting fee for the project’s own cloud service, and quality assurance testing of the upcoming Windows installer by a third party.

The developer seems determined to reach the goal whatever the result of the crowdfunding campaign would be. One week into the fundraiser Gustav got 4 out of 20 modules of the application to compile on Windows, and that’s just the beginning of the journey. There are still 3 weeks to fund it, and then (officially) a month to deliver an actual installer.

If you are not familiar with Tupi and you have either Linux or Mac around, fetch the latest version and give it a spin. The campaign’s page, should you choose to support the project, is right here.

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Guitarix gets octaver plugin, loads external effects

Hermann Meyer released a new version of Guitarix, free/libre guitar FX processor. If you are looking for something that (vaguely) resembles Amplitube or Guitar Rig on Linux, you might want to check this out.

The new version features a long anticipated octaver effect that somewhat misleadingly was called ‘Detune’. What it really does is adding a copy of the input stream with a hardcoded octave-large pitch shift upwards or downwards and an optional detune of up to 1/3 of a semitone from the shifted tone.

GxDetune octaver in Ardour 3

In high quality mode the octaver produces reasonable output from a crunch, but introduces a significant latency even when you choose latency correction. In the real-time mode the latency is more then bearable, but the quality suffers. You really don’t want to use the low quality mode, because you get neither quality, no real-time processing. If you process clean (no crunch) guitar sound, the quality is somewhat debatable even in the high quality mode.

Apart from that, there’s a Baxandall tonestack now (internal only), a Zita convolver based shimmer called GxShimmizita (LV2), and a self-explanatory named GxSwitchedTremolo effect (LV2).

A much appreciated new feature is an ability to insert any installed LADSPA or LV2 effect into the FX chain, so you are not married to internal implementations of chorus, delay etc. anymore.

Calf Multi Chorus LV2 inside Guitarix

Go to ‘Plugins > LADSPA/LV2 plugins’ (Ctrl+U) and mark the effect you want to be used from withing Guitarix, then click Save. Guitarix was automatically distribute the effects across FX categories in its window. Then you can drag’n’drop new effects as usual.

Get Guitarix 0.30.0 at SourceForge.

This, however, isn’t all news. In June, developers released two LV2 plugins:

  • GxBluemann — combines a tube screamer, a 12ax7 tube based amp, a Baxandall tonestack and a cabinet. It has no native UI, and the CPU load is merely ~5%.
  • GxRectifier — an amp made with Orange AD200 in mind, but instead of a single ECC83 tube emulation it has 2×ECC83, 1×ECC81, and 4×6550. Also, it has a 2-band Baxandall tonestack instead of the original 3-band one, as well as a rectifier and a 4×10 cabinet. Hermann is looking forward to feedback from bass players.

Finally, the SpecMatch tool that generates IR files is now shipped separately. You can get it at SourceForge as well.

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Krita team raises €15K on Kickstarter, revisits OSX plans

The first fundraiser by Krita developers is a financial success: three weeks into the campaign, creators of a popular free/libre painting app raised the requested €15K and are now on the way towards the first stretch goal.

With over €16K in the stash and 7 days to go, the team isn’t idle. Over the past few weeks they implemented quite a few new features, including at least one that were supposed to be among deliverables of the campaign:

They also improved robustness of the loading of Photoshop’s ABR brushes, made WMF, EMF, and SVG files loadable into single vector shapes, and improved an existing brush stabilizer.

More importantly, they revisited their plans for an OSX port. The initial idea was to make it the second stretch goal (€75.000 euros). Some of the users were, quite predictably, concerned about that. One typical comment for a coverage at was:

I’m not sure… 75k so they can start on a mac port? Kinda poor form, since if I donate toward that and they don’t reach that ‘goal’, then I’m out money, but still can’t use the software.

The first reaction of the team was:

If we don’t get enough funding for a mac port then we might do a separate kickstarter, but that’ll be next year, and a mac port will then be for, I guess, 3.1 or 3.2.

However, Boudewijn Rempt, lead developer of the project, was determined to show to OSX users that the team means business. He started reevaluating the amount of work that needs to be done to provide a Krita build and discovered that a very basic, proof-of-concept port is already doable.

I thought I’d need that [Qt5 port], but I actually have got a more or less working stripped-down KDE 4 build that has only the bits we need for Krita.

We [still] do need funding to make the OSX port good enough. It’s a huge amount of work: from OpenGL bugs to missing brush engines, from Krita only seeing 1GB of memory to missing dependencies, from a broken right-click palette to GUI ugliness.

Once you go beyond what you can do on your free saturday, development speed depends on available time, which is a direct function of available money.

I guess I will keep making these builds available together with Windows builds, but how good they will be — it depends on the problems I encounter, and the time I can free up for it.

As for the Qt5 port that is a prerequisite for a clean(er) OSX port, there might be another fundraiser around December specifically for that. The team wants the Qt5 port done by March 2015. There are no fixed plans for any further Kickstarter activity other than trying to raise more awareness for the running campaign and go up to at least 20K euros.

The latest build for OSX along with a disclaimer on feature parity against Windows/Linux version is available for downloading. There’s also an unstable build for Windows.

The campaign will end in 7 days, there’s still time to get another developer to work on Krita full-time.

Edit: the campaign closed on July 10 with €19,955 collected.

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Document Liberation project announces EPUB exporting tool

David Tardon of LibreOffice and Document Liberation fame started working on a new library for exporting EPUB files that are typically used for the distribution of ebooks.

The library, predictably called libepubgen, makes use of HTML and SVG content generators from librevenge to create EPUB files and provides API for slightly fancier things like splitting HTML data into multiple files.

David explained a few technical details in his blog post, but there’s always more to find out, and he kindly agreed to answer a few questions.

According to the commits log the tool should make valid EPUB 2.0 files. However in the blog you say “What is still missing is handling of foreign binary objects… I think I will convert these to SVG images”. However, SVG support is an EPUB 3.0 feature. Same goes for MathML equations. So what’s up with that?

I have not mentioned in explicitly, but I am only interested in EPUB 2.0. In my opinion, EPUB 3.0 went the same way as XSLT 2.0 — over-complication rather than improvement. Also, my PRS-505 does not handle EPUB 3.0 🙂

(Editor’s note: Book Industry Study Group’s compatibility grid for EPUB 3.0, even being somewhat outdated, suggests that EPUB 3.0 is still not quite popular among major vendors.)

As for SVG and MathML, that kind of inline code is only supported in EPUB 3.0 indeed. However, SVG images, that is, included through HTML tag “img”, can be used in 2.0, as SVG is one of OPS Core Media Types.

How useful would libepubgen be for a project with its own document model, one that is different from OpenDocument?

I would say that converting the internal document model of an application to librevenge model and then using libepubgen is simpler than generating EPUB directly, unless the document model is already very close to EPUB. But it is really a matter of tradeoffs.

Libepubgen, being based on librevenge, offers the use of a reasonable (we think 🙂 API for creating the document and it shields the user from the gory details of HTML, CSS and EPUB structure. So if the person implementing the export is already familiar with librevenge API, the libepubgen way seems better. On the other hand, if the implementer has detailed knowlegde of HTML, CSS, and EPUB structure, the advantage of libepubgen is much smaller.

Also, using libepubgen means an additional dependency for the project, which might or might not be a problem.

One additional advantage of using libepubgen is that, once one has implemented the document model to librevenge model conversion, it can be reused to export ODF too, through libodfgen.

That was the general view. Now, some thoughts about concrete applications. Scribus bundles the external libraries it uses, so the barrier of adding a new one is higher than in other projects.

On the other hand, Franz [Schmid] at least has had some experience with librevenge API. He has already implemented the librevenge to internal model conversion (for the libmspub and libvisio import), so, if I simplify this a bit, it is only a matter of “reversing” the code to get the other way. Also, they have ODG import, but not export. So the possibility of gaining export to two formats with one code might be appealing to them.

What about adding this exporter to LibreOffice?

It is rather easy to add a new one in our build system. The only concern is the increase in size of the installation sets. So the main question is whether it is needed: there already are two extensions that handle conversion to EPUB, so adding a third way to do it might be excessive 🙂

There would also have to be someone willing to write the integration code (maybe a GSoC task to write conversion code from UNO API to librevenge API for all 4 kinds of documents librevenge supports,and then use that to provide EPUB export through libepubgen).

About those two other projects — are you planning any sort of collaboration with e.g. eLAIX?

No. But I tried both eLAIX and writer2epub in the past. And I heard from other people who have used it; most of the comments were not flattering…

Anyway, there is difference in scope and intended use: eLAIX is apparently written in StarBasic, therefore it is very LibreOffice specific. libepubgen, however, is usable by any tool that can produce the librevenge document stream. This is most easily achieved by plugging one of our import libraries into it, like writerperfect does, but an application can produce it directly too.

So, any application that wishes to export EPUB can do it by producing the doc. stream. But it also allows applications, that can import EPUB, to use our import libraries. In that case EPUB is used as an intermediate format, in the same way like LibreOffice and Calligra use ODF (through libodfgen) or Inkscape uses SVG (through the internal librevenge::RVNGSVGDrawingGenerator).

But that is really just a rationalization. What it boils down to is: I thought EPUB generator was a good idea. I had some time. I did it .-)

Alessandro Rimoldi, who’s been working on EPUB exporting in Scribus for the past few years, commented:

Since I have a good unserstanding of how EPUB, HTML, and CSS work, David himself suggests that there is not much interest for me in his library.

That said, since Scribus is already using librevenge for reading formats, I think it makes sense to use libepubgen… This is also true for long term maintainability and also for providing ODT export!

So libepubgen won’t help me for now, but I think it’s probably be a good investment to move to it in the future.

Source code of libepubgen is available on SourceForge. First official release will be supposedly announced later this year.

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Drawchemy, Android app for sketching, pays tribute to Alchemy

Patrick Pilmeyer released the first public version of Drawchemy, a free/libre sketching app for Android, heavily inspired by Alchemy.

The original application, Alchemy, was once upon a time the darling of Linux-based artists such as David Revoy thanks to certain features that made sketching a bliss — think drawing with mirror symmetry.

In fact, the new app provides both horizontal and vertical symmetry modes and several painting tools with configurable settings: Line, Scraw, Ribbon, Splatter, and XShape. There are some additional settings such as color (you can switch between any two defined in HSB color model), opacity, and stroke width. The app works on a phone like Nexus 4, but you won’t do it justice until you run it on a tablet, really.

Drawchemy on Nexus 4

Regarding the origin of the project Patrick says:

I like to paint on computer, and I use open source drawing programs. Two months ago, I decided to make an Android “version” of Alchemy as a learning project. In the end, it was more than that. I released my application with the name of Drawchemy this week-end on the Google Play. I published my code under GPLv3 license. I also made a tumblr of what I did with it.

Various ideas from Alchemy have already made their way to apps like Krita, so it’s not the first time bits of the original application resurface elsewhere. Why?

It’s a well-known fact that people tend to use software in unpredictable ways, far from what developers originally had in mind. Alchemy embraced that simple truth with both hands and, quite possibly, with both legs as well. Thanks to a plugin system anyone could come up with a new module to create or modify shapes. Which people did — including arcane modules like using the sound from a mic input to affect drawing.

Here David Revoy demonstrates a more conventional approach to sketching with Alchemy:

It feels weird to talk about Alchemy in the past tense, especially since the latest contributed module, Triangles Create, is merely half a year old. However, the last release was made in 2010, latest changes in the source code repository are from 2012, and the forum is plagued by spammers of kitchenware persuasion. The situation wasn’t exactly much better in 2012, shortly after we interviewed Crowline, lead developer of the project at the time.

Since Alchemy is written in Java, porting it to Android in its entirety might prove to be just about doable. But that looks like a major undertaking, while creating new apps that provide some of Alchemy’s features seems easy enough to do.

Drawchemy is, in fact, not the first Android app that reuses ideas from Alchemy. Another project, Webchemy, was first released by Benjamin Vetter as a web app in 2012, then as an Android application earlier this year. The source code is also open and available on GitHub.

Whether Alchemy will eventually get a second chance, remains to be seen. For now, you have two of its offsprings to explore on that shiny gadget you keep carrying around.

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