+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/The_new__best__multimedia_player_in_Debian_.html">The new "best" multimedia player in Debian?</a></div>
+ <div class="date"> 6th June 2016</div>
+ <div class="body"><p>When I set out a few weeks ago to figure out
+<a href="http://people.skolelinux.org/pere/blog/What_is_the_best_multimedia_player_in_Debian_.html">which
+multimedia player in Debian claimed to support most file formats /
+MIME types</a>, I was a bit surprised how varied the sets of MIME types
+the various players claimed support for. The range was from 55 to 130
+MIME types. I suspect most media formats are supported by all
+players, but this is not really reflected in the MimeTypes values in
+their desktop files. There are probably also some bogus MIME types
+listed, but it is hard to identify which one this is.</p>
+
+<p>Anyway, in the mean time I got in touch with upstream for some of
+the players suggesting to add more MIME types to their desktop files,
+and decided to spend some time myself improving the situation for my
+favorite media player VLC. The fixes for VLC entered Debian unstable
+yesterday. The complete list of MIME types can be seen on the
+<a href="https://wiki.debian.org/DebianMultimedia/PlayerSupport">Multimedia
+player MIME type support status</a> Debian wiki page.</p>
+
+<p>The new "best" multimedia player in Debian? It is VLC, followed by
+totem, parole, kplayer, gnome-mpv, mpv, smplayer, mplayer-gui and
+kmplayer. I am sure some of the other players desktop files support
+several of the formats currently listed as working only with vlc,
+toten and parole.</p>
+
+<p>A sad observation is that only 14 MIME types are listed as
+supported by all the tested multimedia players in Debian in their
+desktop files: audio/mpeg, audio/vnd.rn-realaudio, audio/x-mpegurl,
+audio/x-ms-wma, audio/x-scpls, audio/x-wav, video/mp4, video/mpeg,
+video/quicktime, video/vnd.rn-realvideo, video/x-matroska,
+video/x-ms-asf, video/x-ms-wmv and video/x-msvideo. Personally I find
+it sad that video/ogg and video/webm is not supported by all the media
+players in Debian. As far as I can tell, all of them can handle both
+formats.</p>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia</a>, <a href="http://people.skolelinux.org/pere/blog/tags/video">video</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/A_program_should_be_able_to_open_its_own_files_on_Linux.html">A program should be able to open its own files on Linux</a></div>
+ <div class="date"> 5th June 2016</div>
+ <div class="body"><p>Many years ago, when koffice was fresh and with few users, I
+decided to test its presentation tool when making the slides for a
+talk I was giving for NUUG on Japhar, a free Java virtual machine. I
+wrote the first draft of the slides, saved the result and went to bed
+the day before I would give the talk. The next day I took a plane to
+the location where the meeting should take place, and on the plane I
+started up koffice again to polish the talk a bit, only to discover
+that kpresenter refused to load its own data file. I cursed a bit and
+started making the slides again from memory, to have something to
+present when I arrived. I tested that the saved files could be
+loaded, and the day seemed to be rescued. I continued to polish the
+slides until I suddenly discovered that the saved file could no longer
+be loaded into kpresenter. In the end I had to rewrite the slides
+three times, condensing the content until the talk became shorter and
+shorter. After the talk I was able to pinpoint the problem –
+kpresenter wrote inline images in a way itself could not understand.
+Eventually that bug was fixed and kpresenter ended up being a great
+program to make slides. The point I'm trying to make is that we
+expect a program to be able to load its own data files, and it is
+embarrassing to its developers if it can't.</p>
+
+<p>Did you ever experience a program failing to load its own data
+files from the desktop file browser? It is not a uncommon problem. A
+while back I discovered that the screencast recorder
+gtk-recordmydesktop would save an Ogg Theora video file the KDE file
+browser would refuse to open. No video player claimed to understand
+such file. I tracked down the cause being <tt>file --mime-type</tt>
+returning the application/ogg MIME type, which no video player I had
+installed listed as a MIME type they would understand. I asked for
+<a href="http://bugs.gw.com/view.php?id=382">file to change its
+behavour</a> and use the MIME type video/ogg instead. I also asked
+several video players to add video/ogg to their desktop files, to give
+the file browser an idea what to do about Ogg Theora files. After a
+while, the desktop file browsers in Debian started to handle the
+output from gtk-recordmydesktop properly.</p>
+
+<p>But history repeats itself. A few days ago I tested the music
+system Rosegarden again, and I discovered that the KDE and xfce file
+browsers did not know what to do with the Rosegarden project files
+(*.rg). I've reported <a href="http://bugs.debian.org/825993">the
+rosegarden problem to BTS</a> and a fix is commited to git and will be
+included in the next upload. To increase the chance of me remembering
+how to fix the problem next time some program fail to load its files
+from the file browser, here are some notes on how to fix it.</p>
+
+<p>The file browsers in Debian in general operates on MIME types.
+There are two sources for the MIME type of a given file. The output from
+<tt>file --mime-type</tt> mentioned above, and the content of the
+shared MIME type registry (under /usr/share/mime/). The file MIME
+type is mapped to programs supporting the MIME type, and this
+information is collected from
+<a href="https://www.freedesktop.org/wiki/Specifications/desktop-entry-spec/">the
+desktop files</a> available in /usr/share/applications/. If there is
+one desktop file claiming support for the MIME type of the file, it is
+activated when asking to open a given file. If there are more, one
+can normally select which one to use by right-clicking on the file and
+selecting the wanted one using 'Open with' or similar. In general
+this work well. But it depend on each program picking a good MIME
+type (preferably
+<a href="http://www.iana.org/assignments/media-types/media-types.xhtml">a
+MIME type registered with IANA</a>), file and/or the shared MIME
+registry recognizing the file and the desktop file to list the MIME
+type in its list of supported MIME types.</p>
+
+<p>The <tt>/usr/share/mime/packages/rosegarden.xml</tt> entry for
+<a href="http://www.freedesktop.org/wiki/Specifications/shared-mime-info-spec">the
+Shared MIME database</a> look like this:</p>
+
+<p><blockquote><pre>
+<?xml version="1.0" encoding="UTF-8"?>
+<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
+ <mime-type type="audio/x-rosegarden">
+ <sub-class-of type="application/x-gzip"/>
+ <comment>Rosegarden project file</comment>
+ <glob pattern="*.rg"/>
+ </mime-type>
+</mime-info>
+</pre></blockquote></p>
+
+<p>This states that audio/x-rosegarden is a kind of application/x-gzip
+(it is a gzipped XML file). Note, it is much better to use an
+official MIME type registered with IANA than it is to make up ones own
+unofficial ones like the x-rosegarden type used by rosegarden.</p>
+
+<p>The desktop file of the rosegarden program failed to list
+audio/x-rosegarden in its list of supported MIME types, causing the
+file browsers to have no idea what to do with *.rg files:</p>
+
+<p><blockquote><pre>
+% grep Mime /usr/share/applications/rosegarden.desktop
+MimeType=audio/x-rosegarden-composition;audio/x-rosegarden-device;audio/x-rosegarden-project;audio/x-rosegarden-template;audio/midi;
+X-KDE-NativeMimeType=audio/x-rosegarden-composition
+%
+</pre></blockquote></p>
+
+<p>The fix was to add "audio/x-rosegarden;" at the end of the
+MimeType= line.</p>
+
+<p>If you run into a file which fail to open the correct program when
+selected from the file browser, please check out the output from
+<tt>file --mime-type</tt> for the file, ensure the file ending and
+MIME type is registered somewhere under /usr/share/mime/ and check
+that some desktop file under /usr/share/applications/ is claiming
+support for this MIME type. If not, please report a bug to have it
+fixed. :)</p>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Tor___from_its_creators_mouth_11_years_ago.html">Tor - from its creators mouth 11 years ago</a></div>
+ <div class="date">28th May 2016</div>
+ <div class="body"><p>A little more than 11 years ago, one of the creators of Tor, and
+the current President of <a href="https://www.torproject.org/">the Tor
+project</a>, Roger Dingledine, gave a talk for the members of the
+<a href="http://www.nuug.no/">Norwegian Unix User group</a> (NUUG). A
+video of the talk was recorded, and today, thanks to the great help
+from David Noble, I finally was able to publish the video of the talk
+on Frikanalen, the Norwegian open channel TV station where NUUG
+currently publishes its talks. You can
+<a href="http://frikanalen.no/se">watch the live stream using a web
+browser</a> with WebM support, or check out the recording on the video
+on demand page for the talk
+"<a href="http://beta.frikanalen.no/video/625599">Tor: Anonymous
+communication for the US Department of Defence...and you.</a>".</p>
+
+<p>Here is the video included for those of you using browsers with
+HTML video and Ogg Theora support:</p>
+
+<p><video width="70%" poster="http://simula.gunkies.org/media/625599/large_thumb/20050421-tor-frikanalen.jpg" controls>
+ <source src="http://simula.gunkies.org/media/625599/theora/20050421-tor-frikanalen.ogv" type="video/ogg"/>
+</video></p>
+
+<p>I guess the gist of the talk can be summarised quite simply: If you
+want to help the military in USA (and everyone else), use Tor. :)</p>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/frikanalen">frikanalen</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/video">video</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Isenkram_with_PackageKit_support___new_version_0_23_available_in_Debian_unstable.html">Isenkram with PackageKit support - new version 0.23 available in Debian unstable</a></div>
+ <div class="date">25th May 2016</div>
+ <div class="body"><p><a href="https://tracker.debian.org/pkg/isenkram">The isenkram
+system</a> is a user-focused solution in Debian for handling hardware
+related packages. The idea is to have a database of mappings between
+hardware and packages, and pop up a dialog suggesting for the user to
+install the packages to use a given hardware dongle. Some use cases
+are when you insert a Yubikey, it proposes to install the software
+needed to control it; when you insert a braille reader list it
+proposes to install the packages needed to send text to the reader;
+and when you insert a ColorHug screen calibrator it suggests to
+install the driver for it. The system work well, and even have a few
+command line tools to install firmware packages and packages for the
+hardware already in the machine (as opposed to hotpluggable hardware).</p>
+
+<p>The system was initially written using aptdaemon, because I found
+good documentation and example code on how to use it. But aptdaemon
+is going away and is generally being replaced by
+<a href="http://www.freedesktop.org/software/PackageKit/">PackageKit</a>,
+so Isenkram needed a rewrite. And today, thanks to the great patch
+from my college Sunil Mohan Adapa in the FreedomBox project, the
+rewrite finally took place. I've just uploaded a new version of
+Isenkram into Debian Unstable with the patch included, and the default
+for the background daemon is now to use PackageKit. To check it out,
+install the <tt>isenkram</tt> package and insert some hardware dongle
+and see if it is recognised.</p>
+
+<p>If you want to know what kind of packages isenkram would propose for
+the machine it is running on, you can check out the isenkram-lookup
+program. This is what it look like on a Thinkpad X230:</p>
+
+<p><blockquote><pre>
+% isenkram-lookup
+bluez
+cheese
+fprintd
+fprintd-demo
+gkrellm-thinkbat
+hdapsd
+libpam-fprintd
+pidgin-blinklight
+thinkfan
+tleds
+tp-smapi-dkms
+tp-smapi-source
+tpb
+%p
+</pre></blockquote></p>
+
+<p>The hardware mappings come from several places. The preferred way
+is for packages to announce their hardware support using
+<a href="https://www.freedesktop.org/software/appstream/docs/">the
+cross distribution appstream system</a>.
+See
+<a href="http://people.skolelinux.org/pere/blog/tags/isenkram/">previous
+blog posts about isenkram</a> to learn how to do that.</p>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Discharge_rate_estimate_in_new_battery_statistics_collector_for_Debian.html">Discharge rate estimate in new battery statistics collector for Debian</a></div>
+ <div class="date">23rd May 2016</div>
+ <div class="body"><p>Yesterday I updated the
+<a href="https://tracker.debian.org/pkg/battery-stats">battery-stats
+package in Debian</a> with a few patches sent to me by skilled and
+enterprising users. There were some nice user and visible changes.
+First of all, both desktop menu entries now work. A design flaw in
+one of the script made the history graph fail to show up (its PNG was
+dumped in ~/.xsession-errors) if no controlling TTY was available.
+The script worked when called from the command line, but not when
+called from the desktop menu. I changed this to look for a DISPLAY
+variable or a TTY before deciding where to draw the graph, and now the
+graph window pop up as expected.</p>
+
+<p>The next new feature is a discharge rate estimator in one of the
+graphs (the one showing the last few hours). New is also the user of
+colours showing charging in blue and discharge in red. The percentages
+of this graph is relative to last full charge, not battery design
+capacity.</p>
+
+<p align="center"><img src="http://people.skolelinux.org/pere/blog/images/2016-05-23-battery-stats-rate.png"/></p>
+
+<p>The other graph show the entire history of the collected battery
+statistics, comparing it to the design capacity of the battery to
+visualise how the battery life time get shorter over time. The red
+line in this graph is what the previous graph considers 100 percent:
+
+<p align="center"><img src="http://people.skolelinux.org/pere/blog/images/2016-05-23-battery-stats-history.png"/></p>
+
+<p>In this graph you can see that I only charge the battery to 80
+percent of last full capacity, and how the capacity of the battery is
+shrinking. :(</p>
+
+<p>The last new feature is in the collector, which now will handle
+more hardware models. On some hardware, Linux power supply
+information is stored in /sys/class/power_supply/ACAD/, while the
+collector previously only looked in /sys/class/power_supply/AC/. Now
+both are checked to figure if there is power connected to the
+machine.</p>
+
+<p>If you are interested in how your laptop battery is doing, please
+check out the
+<a href="https://tracker.debian.org/pkg/battery-stats">battery-stats</a>
+in Debian unstable, or rebuild it on Jessie to get it working on
+Debian stable. :) The upstream source is available from <a
+href="https://github.com/petterreinholdtsen/battery-stats">github</a>.
+Patches are very welcome.</p>
+
+<p>As usual, if you use Bitcoin and want to show your support of my
+activities, please send Bitcoin donations to my address
+<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>.</p>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
projects / homepage.git / blobdiff