Jopsen.dk/blog

August 24, 2010

Turning OpenOffice Math into a visual formula editor

Filed under: English,LibreOffice,Linux by Jonas Finnemann Jensen at 02:40

I’ve spend most my summer working on my GSoC project, which was to create a visual formula editor for OpenOffice Math. Currently, formulas are entered in OpenOffice Math using a plaintext command language, this can be efficent and easy for power users, however, it’s an absolute show stopper for most casual users. So I’ve spend my summer writing a visual formula editor for OpenOffice Math, you can see demonstration here:

I participated in GSoC for Go OpenOffice, which is a project that maintains a set of patches on top of OpenOffice. Go OpenOffice is the OpenOffice version distributed with OpenSuSE, Ubuntu and other distros, it is allegedly a lot better than the official OpenOffice release. And also available for Windows.

Hacking OpenOffice have been a very exciting experience. I haven’t worked on a project so large and complex before. It easily takes 2 hours to build OpenOffice and the sources and binaries fills about 13 GiB. Luckily I didn’t have to rebuild everytime I had to test something.

The visual formula editor, see video above, is not production ready yet. That is it needs extensive testing and a few extra features… However, I plan to keep working on it. You can read more about it’s features and current status here.

I don’t think I’ll keep updating that wiki page, but rather post some updates here once in a while. If you are eager to help test this feature when it comes that far, feel free to leave a comment with your email…

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August 26, 2009

Working on Pwytter in Google Summe of Code

Filed under: Computer,English,Linux,Pwytter by Jonas Finnemann Jensen at 00:44

This summer I’ve been working on Pwytter as a part of Google Summer of Code. My project was to separate the backend from the frontend and make a new user interface with PyQt. In my original propsal, I also wanted to do a GTK frontend, however, this was dropped in exchange for a more polished Qt frontend (I do have the basics for a GTK frontend lying around, if anybody is interested, but it’s far from usable).

While writing a backend for Pwytter I also created some abstractions for micro-blogging services, so that Pwytter supports multiple accounts and multiple services (currently Twitter and Identi.ca). With this new backend all the messages are also cached in an sqlite database, enabling Pwytter for work while offline.

pwytter

I also added theming support to the Qt frontend I wrote for Pwytter, above is a screenshot of Pwytter running the “Twitter-like” theme (as you can see have also be translated, so far only to Danish). Pwytter uses WebKit to display tweets, users and other types of content, thus themes can customize the GUI using HTML templates and Qt stylesheets. Documentation for writing such themes can be found in the project wiki, I plan to write an article on subject when this Pwytter branch is released. So far this Pwytter branch is still under development, and interested developers can find install instructions in the project wiki.

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December 15, 2008

RaptorMail, an encrypting GMail client

Filed under: Computer,Linux,School by Jonas Finnemann Jensen at 02:30

Tomorrow, I’m finally turning in my P1 project, that’s the first semester project, at Aalborg University. The project is about RSA, and usability of encrypting email clients, and as a part of the project we’ve implemented an encrypting email client for GMail. In Python, with PyGTK and SQLite as backend, e.g. access mail while not online.

Anyway, I thought I’d publish the report here for anyone to stumble upon. Honestly it’s not that great, it’s written in English and is subject to some serious gramma issues, as we’ve been pretty busy actually getting it ready… For those who does not know what a P1 project at AAU is, it is a project conducted by a group of 4-7 students. Most of the education at AAU, happens through these kind of projects, which is kind of nice and gives a lot of freedom. But just for the record, I have not written the entire report myself, so do not blame me all the horror that may be found within it…

Enough about the report, during the project we also wrote an encrypting GMail client, called RaptorMail – don’t ask why. A GMail client is actually quite interesting, if I managed to find the time, it would be real nice to nail the last few bugs and integrate it with GPG… An application to access GMail through a non-webinterface while still maintaining the same feature set would be nice to have. And cacheing all mail for offline usage is an absolute killer-feature.

But I’m afraid I have a lot of other small projects on my mind too, so actually getting it out there is probably not going to happen. But if anybody is looking for a way to synchronize and interface GMail with a local database from Python the “gmail_cache” module I’ve written for this project is fairly comprehensive and well documented.

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December 29, 2007

SimpleECDSA, a simple implementation of ECDSA in C

Filed under: Computer,English,Linux,School by Jonas Finnemann Jensen at 14:32

2 weeks ago I did a school project on ECDSA (Elliptic Curve Digital Signature Algorithm). At HTX we have to do a project that goes beyond the curriculum, we must combine two subjects and do an individual project about something we find interesting. I decided to combine mathematics and programming in a project about ECDSA. Personally I think it was great fun, but perhaps I have a twisted sense of humor

Anyway, I’ve publish my report here, it’s in Danish though. But I did also write an implementation of ECDSA in C. The implementation is called SimpleECDSA, though I must admit it not very Simple anymore. It uses GMP as integer library, and uses the standardized curves cryptographic operations.

The comments in my source is in English, though I did translate them to Danish, before delivering my paper. Anyway, I still have the source with English comments, so I thought I’d post the source here.

As I had a little spare time this holiday I’ve configured the source with the GNU build system. It my first tarball created with Autotools, and it’s mostly hacked together of snippets from the automake and autoconf manual. But it works and the package compiles, and “./configure” complains if GMP isn’t present. I did also manage to get “make check” to run my internal tests, so I think it’s pretty good, considering the fact that is my first package build with autotools.

If you’ve any comments, bug-reports or questions to my packaging or SimpleECDSA, feel free to leave a comment. SimpleECDSA is ofcourse released under GNU GPLv3, and can be downloaded here:

Download SimpleECDSA

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August 30, 2007

Volume normalization with Amarok

Filed under: English,Linux,TheLastRipper by Jonas Finnemann Jensen at 22:08

Some users of TheLastRipper has requested integrated volume nomalization (Issue 61). While I admit that I’ve noticed the volume changes between tracks, I’ve never really bordered to find a solution. But since others had similar issues, I decided to take a look at it. I ended up looking at ReplayGain, a project that aims to add a tag, containing volume information, to all songs. Then read the tag at playback and determine the volume. Though the value of the tag must be calculated first.

As this seams like a big feature, and as argued by Andreas in the issue tread, it’s probably not a feature for TheLastRipper. Nevertheless it doesn’t mean that the problem should be fixed, just that it should be done elsewhere. This is also good, since you entire music collection doesn’t necessarily origin from TheLastRipper. The solution is to implement this feature at playback level, meaning in your audio player.

For those of us running Ubuntu and using Amarok, this can be done easily. First open Amarok, choose “script-management”, Click download new scripts. This will open a dialog showing the newest, most popular and most downloaded script for Amarok. Just install the script called ReplayGain. Once this is installed you’ll have to install some dependencies with Synaptic. I’ll try to list those I think is needed: python-kde3, mp3gain, vorbisgain, flac, python-xml

If you enter the script-management in Amarok again, you can enable the ReplayGain script. Enable it, select it and click “Settings”, you can tweak the ReplayGain script a little here. Once your done with that leave the settings, and ReplayGain will print a small popup, telling you which optional dependencies you are missing. I’ve probably forgot to list some of them, you may find them in Synaptic if you think you need them. Though I haven’t found “aacgain” or “replaygain” in the Ubuntu repositories.

Well, you don’t need “replaygain” or “AACGain”, unless you, like me, have AAC music. Actually I’ve just bought my first AAC music from iTunes. I haven’t used iTunes before, but I thought I’d give it a try since they started releasing DRM-free content. So I installed iTunes in my virtual machine, and copied the AAC files back to my Ubuntu system after they were downloaded. First I must say, the quality of iTunes plus files are very good, and the files has ID3v2 tags (other mp3′s I’ve bought online did!). It’s sad that iTunes doesn’t run on Linux, Apple could at least offer a web interface for iTunes plus.

Well, if you have AAC encoded music, you’ll need AACGain, it’s not in Ubuntu or Debian repositories. Actually I couldn’t find any .deb packages for it anywhere. So I decided to make my own. You may download my ACCGain package here. Feel free to contact me if you want the source package.

Once you’re done installing dependencies, and have enabled the ReplayGain Amarok script, you can right click in your playlist and choose “Apply Replaygain tags”, I selected “To entire collection using album tags” it took a while but the volume was automatically determined by Amarok afterwards.

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