<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/A_one_way_wall_on_the_border_.html">A one-way wall on the border?</a></div>
- <div class="date">14th October 2017</div>
- <div class="body"><p>I find it fascinating how many of the people being locked inside
-the proposed border wall between USA and Mexico support the idea. The
-proposal to keep Mexicans out reminds me of
-<a href="http://www.history.com/news/10-things-you-may-not-know-about-the-berlin-wall">the
-propaganda twist from the East Germany government</a> calling the wall
-the “Antifascist Bulwark” after erecting the Berlin Wall, claiming
-that the wall was erected to keep enemies from creeping into East
-Germany, while it was obvious to the people locked inside it that it
-was erected to keep the people from escaping.</p>
-
-<p>Do the people in USA supporting this wall really believe it is a
-one way wall, only keeping people on the outside from getting in,
-while not keeping people in the inside from getting out?</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Software_created_using_taxpayers__money_should_be_Free_Software.html">Software created using taxpayers’ money should be Free Software</a></div>
+ <div class="date">30th August 2018</div>
+ <div class="body"><p>It might seem obvious that software created using tax money should
+be available for everyone to use and improve. Free Software
+Foundation Europe recentlystarted a campaign to help get more people
+to understand this, and I just signed the petition on
+<a href="https://publiccode.eu/">Public Money, Public Code</a> to help
+them. I hope you too will do the same.</p>
</div>
<div class="tags">
- Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett</a>.
</div>
<div class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Generating_3D_prints_in_Debian_using_Cura_and_Slic3r__prusa_.html">Generating 3D prints in Debian using Cura and Slic3r(-prusa)</a></div>
- <div class="date"> 9th October 2017</div>
- <div class="body"><p>At my nearby maker space,
-<a href="http://sonen.ifi.uio.no/">Sonen</a>, I heard the story that it
-was easier to generate gcode files for theyr 3D printers (Ultimake 2+)
-on Windows and MacOS X than Linux, because the software involved had
-to be manually compiled and set up on Linux while premade packages
-worked out of the box on Windows and MacOS X. I found this annoying,
-as the software involved,
-<a href="https://github.com/Ultimaker/Cura">Cura</a>, is free software
-and should be trivial to get up and running on Linux if someone took
-the time to package it for the relevant distributions. I even found
-<a href="https://bugs.debian.org/706656">a request for adding into
-Debian</a> from 2013, which had seem some activity over the years but
-never resulted in the software showing up in Debian. So a few days
-ago I offered my help to try to improve the situation.</p>
-
-<p>Now I am very happy to see that all the packages required by a
-working Cura in Debian are uploaded into Debian and waiting in the NEW
-queue for the ftpmasters to have a look. You can track the progress
-on
-<a href="https://qa.debian.org/developer.php?email=3dprinter-general%40lists.alioth.debian.org">the
-status page for the 3D printer team</a>.</p>
-
-<p>The uploaded packages are a bit behind upstream, and was uploaded
-now to get slots in <a href="https://ftp-master.debian.org/new.html">the NEW
-queue</a> while we work up updating the packages to the latest
-upstream version.</p>
-
-<p>On a related note, two competitors for Cura, which I found harder
-to use and was unable to configure correctly for Ultimaker 2+ in the
-short time I spent on it, are already in Debian. If you are looking
-for 3D printer "slicers" and want something already available in
-Debian, check out
-<a href="https://tracker.debian.org/pkg/slic3r">slic3r</a> and
-<a href="https://tracker.debian.org/pkg/slic3r-prusa">slic3r-prusa</a>.
-The latter is a fork of the former.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/A_bit_more_on_privacy_respecting_health_monitor___fitness_tracker.html">A bit more on privacy respecting health monitor / fitness tracker</a></div>
+ <div class="date">13th August 2018</div>
+ <div class="body"><p>A few days ago, I wondered if there are any privacy respecting
+health monitors and/or fitness trackers available for sale these days.
+I would like to buy one, but do not want to share my personal data
+with strangers, nor be forced to have a mobile phone to get data out
+of the unit. I've received some ideas, and would like to share them
+with you.
+
+One interesting data point was a pointer to a Free Software app for
+Android named
+<a href="https://github.com/Freeyourgadget/Gadgetbridge/">Gadgetbridge</a>.
+It provide cloudless collection and storing of data from a variety of
+trackers. Its
+<a href="https://github.com/Freeyourgadget/Gadgetbridge/#supported-devices">list
+of supported devices</a> is a good indicator for units where the
+protocol is fairly open, as it is obviously being handled by Free
+Software. Other units are reportedly encrypting the collected
+information with their own public key, making sure only the vendor
+cloud service is able to extract data from the unit. The people
+contacting me about Gadgetbirde said they were using
+<a href="https://us.amazfit.com/shop/bip?variant=336750">Amazfit
+Bip</a> and
+<a href="http://www.xiaomimi6phone.com/xiaomi-mi-band-3-features-release-date-rumors/">Xiaomi
+Band 3</a>.</p>
+
+<p>I also got a suggestion to look at some of the units from Garmin.
+I was told their GPS watches can be connected via USB and show up as a
+USB storage device with
+<a href="https://www.gpsbabel.org/htmldoc-development/fmt_garmin_fit.html">Garmin
+FIT files</a> containing the collected measurements. While
+proprietary, FIT files apparently can be read at least by
+<a href="https://www.gpsbabel.org">GPSBabel</a> and the
+<a href="https://apps.nextcloud.com/apps/gpxpod">GpxPod</a> Nextcloud
+app. It is unclear to me if they can read step count and heart rate
+data. The person I talked to was using a
+<a href="https://buy.garmin.com/en-US/US/p/564291">Garmin Forerunner
+935</a>, which is a fairly expensive unit. I doubt it is worth it for
+a unit where the vendor clearly is trying its best to move from open
+to closed systems. I still remember when Garmin dropped NMEA support
+in its GPSes.</p>
+
+<p>A final idea was to build ones own unit, perhaps by basing it on a
+wearable hardware platforms like
+<a href="https://learn.adafruit.com/flora-geo-watch">the Flora Geo
+Watch</a>. Sound like fun, but I had more money than time to spend on
+the topic, so I suspect it will have to wait for another time.</p>
+
+<p>While I was working on tracking down links, I came across an
+inspiring TED talk by Dave Debronkart about
+<a href="https://archive.org/details/DavedeBronkart_2010X">being a
+e-patient</a>, and discovered the web site
+<a href="https://participatorymedicine.org/epatients/">Participatory
+Medicine</a>. If you too want to track your own health and fitness
+without having information about your private life floating around on
+computers owned by others, I recommend checking it out.</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/3d-printer">3d-printer</a>, <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
</div>
<div class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Mangler_du_en_skrue__eller_har_du_en_skrue_l_s_.html">Mangler du en skrue, eller har du en skrue løs?</a></div>
- <div class="date"> 4th October 2017</div>
- <div class="body">Når jeg holder på med ulike prosjekter, så trenger jeg stadig ulike
-skruer. Det siste prosjektet jeg holder på med er å lage
-<a href="https://www.thingiverse.com/thing:676916">en boks til en
-HDMI-touch-skjerm</a> som skal brukes med Raspberry Pi. Boksen settes
-sammen med skruer og bolter, og jeg har vært i tvil om hvor jeg kan
-få tak i de riktige skruene. Clas Ohlson og Jernia i nærheten har
-sjelden hatt det jeg trenger. Men her om dagen fikk jeg et fantastisk
-tips for oss som bor i Oslo.
-<a href="http://www.zachskruer.no/">Zachariassen Jernvare AS</a> i
-<a href="http://www.openstreetmap.org/?mlat=59.93421&mlon=10.76795#map=19/59.93421/10.76795">Hegermannsgate
-23A på Torshov</a> har et fantastisk utvalg, og åpent mellom 09:00 og
-17:00. De selger skruer, muttere, bolter, skiver etc i løs vekt, og
-så langt har jeg fått alt jeg har lett etter. De har i tillegg det
-meste av annen jernvare, som verktøy, lamper, ledninger, etc. Jeg
-håper de har nok kunder til å holde det gående lenge, da dette er en
-butikk jeg kommer til å besøke ofte. Butikken er et funn å ha i
-nabolaget for oss som liker å bygge litt selv. :)</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Privacy_respecting_health_monitor___fitness_tracker_.html">Privacy respecting health monitor / fitness tracker?</a></div>
+ <div class="date"> 7th August 2018</div>
+ <div class="body"><p>Dear lazyweb,</p>
+
+<p>I wonder, is there a fitness tracker / health monitor available for
+sale today that respect the users privacy? With this I mean a
+watch/bracelet capable of measuring pulse rate and other
+fitness/health related values (and by all means, also the correct time
+and location if possible), which is <strong>only</strong> provided for
+me to extract/read from the unit with computer without a radio beacon
+and Internet connection. In other words, it do not depend on a cell
+phone app, and do make the measurements available via other peoples
+computer (aka "the cloud"). The collected data should be available
+using only free software. I'm not interested in depending on some
+non-free software that will leave me high and dry some time in the
+future. I've been unable to find any such unit. I would like to buy
+it. The ones I have seen for sale here in Norway are proud to report
+that they share my health data with strangers (aka "cloud enabled").
+Is there an alternative? I'm not interested in giving money to people
+requiring me to accept "privacy terms" to allow myself to measure my
+own health.</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/norsk">norsk</a>.
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
</div>
<div class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Visualizing_GSM_radio_chatter_using_gr_gsm_and_Hopglass.html">Visualizing GSM radio chatter using gr-gsm and Hopglass</a></div>
- <div class="date">29th September 2017</div>
- <div class="body"><p>Every mobile phone announce its existence over radio to the nearby
-mobile cell towers. And this radio chatter is available for anyone
-with a radio receiver capable of receiving them. Details about the
-mobile phones with very good accuracy is of course collected by the
-phone companies, but this is not the topic of this blog post. The
-mobile phone radio chatter make it possible to figure out when a cell
-phone is nearby, as it include the SIM card ID (IMSI). By paying
-attention over time, one can see when a phone arrive and when it leave
-an area. I believe it would be nice to make this information more
-available to the general public, to make more people aware of how
-their phones are announcing their whereabouts to anyone that care to
-listen.</p>
-
-<p>I am very happy to report that we managed to get something
-visualizing this information up and running for
-<a href="http://norwaymakers.org/osf17">Oslo Skaperfestival 2017</a>
-(Oslo Makers Festival) taking place today and tomorrow at Deichmanske
-library. The solution is based on the
-<a href="http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html">simple
-recipe for listening to GSM chatter</a> I posted a few days ago, and
-will show up at the stand of <a href="http://sonen.ifi.uio.no/">Åpen
-Sone from the Computer Science department of the University of
-Oslo</a>. The presentation will show the nearby mobile phones (aka
-IMSIs) as dots in a web browser graph, with lines to the dot
-representing mobile base station it is talking to. It was working in
-the lab yesterday, and was moved into place this morning.</p>
-
-<p>We set up a fairly powerful desktop machine using Debian
-Buster/Testing with several (five, I believe) RTL2838 DVB-T receivers
-connected and visualize the visible cell phone towers using an
-<a href="https://github.com/marlow925/hopglass">English version of
-Hopglass</a>. A fairly powerfull machine is needed as the
-grgsm_livemon_headless processes from
-<a href="https://tracker.debian.org/pkg/gr-gsm">gr-gsm</a> converting
-the radio signal to data packages is quite CPU intensive.</p>
-
-<p>The frequencies to listen to, are identified using a slightly
-patched scan-and-livemon (to set the --args values for each receiver),
-and the Hopglass data is generated using the
-<a href="https://github.com/petterreinholdtsen/IMSI-catcher/tree/meshviewer-output">patches
-in my meshviewer-output branch</a>. For some reason we could not get
-more than four SDRs working. There is also a geographical map trying
-to show the location of the base stations, but I believe their
-coordinates are hardcoded to some random location in Germany, I
-believe. The code should be replaced with code to look up location in
-a text file, a sqlite database or one of the online databases
-mentioned in
-<a href="https://github.com/Oros42/IMSI-catcher/issues/14">the github
-issue for the topic</a>.
-
-<p>If this sound interesting, visit the stand at the festival!</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Sharing_images_with_friends_and_family_using_RSS_and_EXIF_XMP_metadata.html">Sharing images with friends and family using RSS and EXIF/XMP metadata</a></div>
+ <div class="date">31st July 2018</div>
+ <div class="body"><p>For a while now, I have looked for a sensible way to share images
+with my family using a self hosted solution, as it is unacceptable to
+place images from my personal life under the control of strangers
+working for data hoarders like Google or Dropbox. The last few days I
+have drafted an approach that might work out, and I would like to
+share it with you. I would like to publish images on a server under
+my control, and point some Internet connected display units using some
+free and open standard to the images I published. As my primary
+language is not limited to ASCII, I need to store metadata using
+UTF-8. Many years ago, I hoped to find a digital photo frame capable
+of reading a RSS feed with image references (aka using the
+<enclosure> RSS tag), but was unable to find a current supplier
+of such frames. In the end I gave up that approach.</p>
+
+<p>Some months ago, I discovered that
+<a href="https://www.jwz.org/xscreensaver/">XScreensaver</a> is able to
+read images from a RSS feed, and used it to set up a screen saver on
+my home info screen, showing images from the Daily images feed from
+NASA. This proved to work well. More recently I discovered that
+<a href="https://kodi.tv">Kodi</a> (both using
+<a href="https://www.openelec.tv/">OpenELEC</a> and
+<a href="https://libreelec.tv">LibreELEC</a>) provide the
+<a href="https://github.com/grinsted/script.screensaver.feedreader">Feedreader</a>
+screen saver capable of reading a RSS feed with images and news. For
+fun, I used it this summer to test Kodi on my parents TV by hooking up
+a Raspberry PI unit with LibreELEC, and wanted to provide them with a
+screen saver showing selected pictures from my selection.</p>
+
+<p>Armed with motivation and a test photo frame, I set out to generate
+a RSS feed for the Kodi instance. I adjusted my <a
+href="https://freedombox.org/">Freedombox</a> instance, created
+/var/www/html/privatepictures/, wrote a small Perl script to extract
+title and description metadata from the photo files and generate the
+RSS file. I ended up using Perl instead of python, as the
+libimage-exiftool-perl Debian package seemed to handle the EXIF/XMP
+tags I ended up using, while python3-exif did not. The relevant EXIF
+tags only support ASCII, so I had to find better alternatives. XMP
+seem to have the support I need.</p>
+
+<p>I am a bit unsure which EXIF/XMP tags to use, as I would like to
+use tags that can be easily added/updated using normal free software
+photo managing software. I ended up using the tags set using this
+exiftool command, as these tags can also be set using digiKam:</p>
+
+<blockquote><pre>
+exiftool -headline='The RSS image title' \
+ -description='The RSS image description.' \
+ -subject+=for-family photo.jpeg
+</pre></blockquote>
+
+<p>I initially tried the "-title" and "keyword" tags, but they were
+invisible in digiKam, so I changed to "-headline" and "-subject". I
+use the keyword/subject 'for-family' to flag that the photo should be
+shared with my family. Images with this keyword set are located and
+copied into my Freedombox for the RSS generating script to find.</p>
+
+<p>Are there better ways to do this? Get in touch if you have better
+suggestions.</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>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>.
+ 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 class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Easier_recipe_to_observe_the_cell_phones_around_you.html">Easier recipe to observe the cell phones around you</a></div>
- <div class="date">24th September 2017</div>
- <div class="body"><p>A little more than a month ago I wrote
-<a href="http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html">how
-to observe the SIM card ID (aka IMSI number) of mobile phones talking
-to nearby mobile phone base stations using Debian GNU/Linux and a
-cheap USB software defined radio</a>, and thus being able to pinpoint
-the location of people and equipment (like cars and trains) with an
-accuracy of a few kilometer. Since then we have worked to make the
-procedure even simpler, and it is now possible to do this without any
-manual frequency tuning and without building your own packages.</p>
-
-<p>The <a href="https://tracker.debian.org/pkg/gr-gsm">gr-gsm</a>
-package is now included in Debian testing and unstable, and the
-IMSI-catcher code no longer require root access to fetch and decode
-the GSM data collected using gr-gsm.</p>
-
-<p>Here is an updated recipe, using packages built by Debian and a git
-clone of two python scripts:</p>
-
-<ol>
-
-<li>Start with a Debian machine running the Buster version (aka
- testing).</li>
-
-<li>Run '<tt>apt install gr-gsm python-numpy python-scipy
- python-scapy</tt>' as root to install required packages.</li>
-
-<li>Fetch the code decoding GSM packages using '<tt>git clone
- github.com/Oros42/IMSI-catcher.git</tt>'.</li>
-
-<li>Insert USB software defined radio supported by GNU Radio.</li>
-
-<li>Enter the IMSI-catcher directory and run '<tt>python
- scan-and-livemon</tt>' to locate the frequency of nearby base
- stations and start listening for GSM packages on one of them.</li>
-
-<li>Enter the IMSI-catcher directory and run '<tt>python
- simple_IMSI-catcher.py</tt>' to display the collected information.</li>
-
-</ol>
-
-<p>Note, due to a bug somewhere the scan-and-livemon program (actually
-<a href="https://github.com/ptrkrysik/gr-gsm/issues/336">its underlying
-program grgsm_scanner</a>) do not work with the HackRF radio. It does
-work with RTL 8232 and other similar USB radio receivers you can get
-very cheaply
-(<a href="https://www.ebay.com/sch/items/?_nkw=rtl+2832">for example
-from ebay</a>), so for now the solution is to scan using the RTL radio
-and only use HackRF for fetching GSM data.</p>
-
-<p>As far as I can tell, a cell phone only show up on one of the
-frequencies at the time, so if you are going to track and count every
-cell phone around you, you need to listen to all the frequencies used.
-To listen to several frequencies, use the --numrecv argument to
-scan-and-livemon to use several receivers. Further, I am not sure if
-phones using 3G or 4G will show as talking GSM to base stations, so
-this approach might not see all phones around you. I typically see
-0-400 IMSI numbers an hour when looking around where I live.</p>
-
-<p>I've tried to run the scanner on a
-<a href="https://wiki.debian.org/RaspberryPi">Raspberry Pi 2 and 3
-running Debian Buster</a>, but the grgsm_livemon_headless process seem
-to be too CPU intensive to keep up. When GNU Radio print 'O' to
-stdout, I am told there it is caused by a buffer overflow between the
-radio and GNU Radio, caused by the program being unable to read the
-GSM data fast enough. If you see a stream of 'O's from the terminal
-where you started scan-and-livemon, you need a give the process more
-CPU power. Perhaps someone are able to optimize the code to a point
-where it become possible to set up RPi3 based GSM sniffers? I tried
-using Raspbian instead of Debian, but there seem to be something wrong
-with GNU Radio on raspbian, causing glibc to abort().</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Simple_streaming_the_Linux_desktop_to_Kodi_using_GStreamer_and_RTP.html">Simple streaming the Linux desktop to Kodi using GStreamer and RTP</a></div>
+ <div class="date">12th July 2018</div>
+ <div class="body"><p>Last night, I wrote
+<a href="http://people.skolelinux.org/pere/blog/Streaming_the_Linux_desktop_to_Kodi_using_VLC_and_RTSP.html">a
+recipe to stream a Linux desktop using VLC to a instance of Kodi</a>.
+During the day I received valuable feedback, and thanks to the
+suggestions I have been able to rewrite the recipe into a much simpler
+approach requiring no setup at all. It is a single script that take
+care of it all.</p>
+
+<p>This new script uses GStreamer instead of VLC to capture the
+desktop and stream it to Kodi. This fixed the video quality issue I
+saw initially. It further removes the need to add a m3u file on the
+Kodi machine, as it instead connects to
+<a href="https://kodi.wiki/view/JSON-RPC_API/v8">the JSON-RPC API in
+Kodi</a> and simply ask Kodi to play from the stream created using
+GStreamer. Streaming the desktop to Kodi now become trivial. Copy
+the script below, run it with the DNS name or IP address of the kodi
+server to stream to as the only argument, and watch your screen show
+up on the Kodi screen. Note, it depend on multicast on the local
+network, so if you need to stream outside the local network, the
+script must be modified. Also note, I have no idea if audio work, as
+I only care about the picture part.</p>
+
+<blockquote><pre>
+#!/bin/sh
+#
+# Stream the Linux desktop view to Kodi. See
+# http://people.skolelinux.org/pere/blog/Streaming_the_Linux_desktop_to_Kodi_using_VLC_and_RTSP.html
+# for backgorund information.
+
+# Make sure the stream is stopped in Kodi and the gstreamer process is
+# killed if something go wrong (for example if curl is unable to find the
+# kodi server). Do the same when interrupting this script.
+kodicmd() {
+ host="$1"
+ cmd="$2"
+ params="$3"
+ curl --silent --header 'Content-Type: application/json' \
+ --data-binary "{ \"id\": 1, \"jsonrpc\": \"2.0\", \"method\": \"$cmd\", \"params\": $params }" \
+ "http://$host/jsonrpc"
+}
+cleanup() {
+ if [ -n "$kodihost" ] ; then
+ # Stop the playing when we end
+ playerid=$(kodicmd "$kodihost" Player.GetActivePlayers "{}" |
+ jq .result[].playerid)
+ kodicmd "$kodihost" Player.Stop "{ \"playerid\" : $playerid }" > /dev/null
+ fi
+ if [ "$gstpid" ] && kill -0 "$gstpid" >/dev/null 2>&1; then
+ kill "$gstpid"
+ fi
+}
+trap cleanup EXIT INT
+
+if [ -n "$1" ]; then
+ kodihost=$1
+ shift
+else
+ kodihost=kodi.local
+fi
+
+mcast=239.255.0.1
+mcastport=1234
+mcastttl=1
+
+pasrc=$(pactl list | grep -A2 'Source #' | grep 'Name: .*\.monitor$' | \
+ cut -d" " -f2|head -1)
+gst-launch-1.0 ximagesrc use-damage=0 ! video/x-raw,framerate=30/1 ! \
+ videoconvert ! queue2 ! \
+ x264enc bitrate=8000 speed-preset=superfast tune=zerolatency qp-min=30 \
+ key-int-max=15 bframes=2 ! video/x-h264,profile=high ! queue2 ! \
+ mpegtsmux alignment=7 name=mux ! rndbuffersize max=1316 min=1316 ! \
+ udpsink host=$mcast port=$mcastport ttl-mc=$mcastttl auto-multicast=1 sync=0 \
+ pulsesrc device=$pasrc ! audioconvert ! queue2 ! avenc_aac ! queue2 ! mux. \
+ > /dev/null 2>&1 &
+gstpid=$!
+
+# Give stream a second to get going
+sleep 1
+
+# Ask kodi to start streaming using its JSON-RPC API
+kodicmd "$kodihost" Player.Open \
+ "{\"item\": { \"file\": \"udp://@$mcast:$mcastport\" } }" > /dev/null
+
+# wait for gst to end
+wait "$gstpid"
+</pre></blockquote>
+
+<p>I hope you find the approach useful. I know I do.</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>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>.
+ 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/video">video</a>.
</div>
<div class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_kaster_skygger_over_H_yre_og_Arbeiderpartiet.html">Datalagringsdirektivet kaster skygger over Høyre og Arbeiderpartiet</a></div>
- <div class="date"> 7th September 2017</div>
- <div class="body"><p>For noen dager siden publiserte Jon Wessel-Aas en bloggpost om
-«<a href="http://www.uhuru.biz/?p=1821">Konklusjonen om datalagring som
-EU-kommisjonen ikke ville at vi skulle få se</a>». Det er en
-interessant gjennomgang av EU-domstolens syn på snurpenotovervåkning
-av befolkningen, som er klar på at det er i strid med
-EU-lovgivingen.</p>
-
-<p>Valgkampen går for fullt i Norge, og om noen få dager er siste
-frist for å avgi stemme. En ting er sikkert, Høyre og Arbeiderpartiet
-får ikke min stemme
-<a href="http://people.skolelinux.org/pere/blog/Datalagringsdirektivet_gj_r_at_Oslo_H_yre_og_Arbeiderparti_ikke_f_r_min_stemme_i__r.html">denne
-gangen heller</a>. Jeg har ikke glemt at de tvang igjennom loven som
-skulle pålegge alle data- og teletjenesteleverandører å overvåke alle
-sine kunder. En lov som er vedtatt, og aldri opphevet igjen.</p>
-
-<p>Det er tydelig fra diskusjonen rundt grenseløs digital overvåkning
-(eller "Digital Grenseforsvar" som det kalles i Orvellisk nytale) at
-hverken Høyre og Arbeiderpartiet har noen prinsipielle sperrer mot å
-overvåke hele befolkningen, og diskusjonen så langt tyder på at flere
-av de andre partiene heller ikke har det. Mange av
-<a href="https://data.holderdeord.no/votes/1301946411e">de som stemte
-for Datalagringsdirektivet i Stortinget</a> (64 fra Arbeiderpartiet,
-25 fra Høyre) er fortsatt aktive og argumenterer fortsatt for å radere
-vekk mer av innbyggernes privatsfære.</p>
-
-<p>Når myndighetene demonstrerer sin mistillit til folket, tror jeg
-folket selv bør legge litt innsats i å verne sitt privatliv, ved å ta
-i bruk ende-til-ende-kryptert kommunikasjon med sine kjente og kjære,
-og begrense hvor mye privat informasjon som deles med uvedkommende.
-Det er jo ingenting som tyder på at myndighetene kommer til å være vår
-privatsfære.
-<a href="http://people.skolelinux.org/pere/blog/How_to_talk_with_your_loved_ones_in_private.html">Det
-er mange muligheter</a>. Selv har jeg litt sans for
-<a href="https://ring.cx/">Ring</a>, som er basert på p2p-teknologi
-uten sentral kontroll, er fri programvare, og støtter meldinger, tale
-og video. Systemet er tilgjengelig ut av boksen fra
-<a href="https://tracker.debian.org/pkg/ring">Debian</a> og
-<a href="https://launchpad.net/ubuntu/+source/ring">Ubuntu</a>, og det
-finnes pakker for Android, MacOSX og Windows. Foreløpig er det få
-brukere med Ring, slik at jeg også bruker
-<a href="https://signal.org/">Signal</a> som nettleserutvidelse.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Streaming_the_Linux_desktop_to_Kodi_using_VLC_and_RTSP.html">Streaming the Linux desktop to Kodi using VLC and RTSP</a></div>
+ <div class="date">12th July 2018</div>
+ <div class="body"><p>PS: See
+<ahref="http://people.skolelinux.org/pere/blog/Simple_streaming_the_Linux_desktop_to_Kodi_using_GStreamer_and_RTP.html">the
+followup post</a> for a even better approach.</p>
+
+<p>A while back, I was asked by a friend how to stream the desktop to
+my projector connected to Kodi. I sadly had to admit that I had no
+idea, as it was a task I never had tried. Since then, I have been
+looking for a way to do so, preferable without much extra software to
+install on either side. Today I found a way that seem to kind of
+work. Not great, but it is a start.</p>
+
+<p>I had a look at several approaches, for example
+<a href="https://github.com/mfoetsch/dlna_live_streaming">using uPnP
+DLNA as described in 2011</a>, but it required a uPnP server, fuse and
+local storage enough to store the stream locally. This is not going
+to work well for me, lacking enough free space, and it would
+impossible for my friend to get working.</p>
+
+<p>Next, it occurred to me that perhaps I could use VLC to create a
+video stream that Kodi could play. Preferably using
+broadcast/multicast, to avoid having to change any setup on the Kodi
+side when starting such stream. Unfortunately, the only recipe I
+could find using multicast used the rtp protocol, and this protocol
+seem to not be supported by Kodi.</p>
+
+<p>On the other hand, the rtsp protocol is working! Unfortunately I
+have to specify the IP address of the streaming machine in both the
+sending command and the file on the Kodi server. But it is showing my
+desktop, and thus allow us to have a shared look on the big screen at
+the programs I work on.</p>
+
+<p>I did not spend much time investigating codeces. I combined the
+rtp and rtsp recipes from
+<a href="https://wiki.videolan.org/Documentation:Streaming_HowTo/Command_Line_Examples/">the
+VLC Streaming HowTo/Command Line Examples</a>, and was able to get
+this working on the desktop/streaming end.</p>
+
+<blockquote><pre>
+vlc screen:// --sout \
+ '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{dst=projector.local,port=1234,sdp=rtsp://192.168.11.4:8080/test.sdp}'
+</pre></blockquote>
+
+<p>I ssh-ed into my Kodi box and created a file like this with the
+same IP address:</p>
+
+<blockquote><pre>
+echo rtsp://192.168.11.4:8080/test.sdp \
+ > /storage/videos/screenstream.m3u
+</pre></blockquote>
+
+<p>Note the 192.168.11.4 IP address is my desktops IP address. As far
+as I can tell the IP must be hardcoded for this to work. In other
+words, if someone elses machine is going to do the steaming, you have
+to update screenstream.m3u on the Kodi machine and adjust the vlc
+recipe. To get started, locate the file in Kodi and select the m3u
+file while the VLC stream is running. The desktop then show up in my
+big screen. :)</p>
+
+<p>When using the same technique to stream a video file with audio,
+the audio quality is really bad. No idea if the problem is package
+loss or bad parameters for the transcode. I do not know VLC nor Kodi
+enough to tell.</p>
+
+<p><strong>Update 2018-07-12</strong>: Johannes Schauer send me a few
+succestions and reminded me about an important step. The "screen:"
+input source is only available once the vlc-plugin-access-extra
+package is installed on Debian. Without it, you will see this error
+message: "VLC is unable to open the MRL 'screen://'. Check the log
+for details." He further found that it is possible to drop some parts
+of the VLC command line to reduce the amount of hardcoded information.
+It is also useful to consider using cvlc to avoid having the VLC
+window in the desktop view. In sum, this give us this command line on
+the source end
+
+<blockquote><pre>
+cvlc screen:// --sout \
+ '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{sdp=rtsp://:8080/}'
+</pre></blockquote>
+
+<p>and this on the Kodi end<p>
+
+<blockquote><pre>
+echo rtsp://192.168.11.4:8080/ \
+ > /storage/videos/screenstream.m3u
+</pre></blockquote>
+
+<p>Still bad image quality, though. But I did discover that streaming
+a DVD using dvdsimple:///dev/dvd as the source had excellent video and
+audio quality, so I guess the issue is in the input or transcoding
+parts, not the rtsp part. I've tried to change the vb and ab
+parameters to use more bandwidth, but it did not make a
+difference.</p>
+
+<p>I further received a suggestion from Einar Haraldseid to try using
+gstreamer instead of VLC, and this proved to work great! He also
+provided me with the trick to get Kodi to use a multicast stream as
+its source. By using this monstrous oneliner, I can stream my desktop
+with good video quality in reasonable framerate to the 239.255.0.1
+multicast address on port 1234:
+
+<blockquote><pre>
+gst-launch-1.0 ximagesrc use-damage=0 ! video/x-raw,framerate=30/1 ! \
+ videoconvert ! queue2 ! \
+ x264enc bitrate=8000 speed-preset=superfast tune=zerolatency qp-min=30 \
+ key-int-max=15 bframes=2 ! video/x-h264,profile=high ! queue2 ! \
+ mpegtsmux alignment=7 name=mux ! rndbuffersize max=1316 min=1316 ! \
+ udpsink host=239.255.0.1 port=1234 ttl-mc=1 auto-multicast=1 sync=0 \
+ pulsesrc device=$(pactl list | grep -A2 'Source #' | \
+ grep 'Name: .*\.monitor$' | cut -d" " -f2|head -1) ! \
+ audioconvert ! queue2 ! avenc_aac ! queue2 ! mux.
+</pre></blockquote>
+
+<p>and this on the Kodi end<p>
+
+<blockquote><pre>
+echo udp://@239.255.0.1:1234 \
+ > /storage/videos/screenstream.m3u
+</pre></blockquote>
+
+<p>Note the trick to pick a valid pulseaudio source. It might not
+pick the one you need. This approach will of course lead to trouble
+if more than one source uses the same multicast port and address.
+Note the ttl-mc=1 setting, which limit the multicast packages to the
+local network. If the value is increased, your screen will be
+broadcasted further, one network "hop" for each increase (read up on
+multicast to learn more. :)!</p>
+
+<p>Having cracked how to get Kodi to receive multicast streams, I
+could use this VLC command to stream to the same multicast address.
+The image quality is way better than the rtsp approach, but gstreamer
+seem to be doing a better job.</p>
+
+<blockquote><pre>
+cvlc screen:// --sout '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{mux=ts,dst=239.255.0.1,port=1234,sdp=sap}'
+</pre></blockquote>
+
+<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/dld">dld</a>, <a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk</a>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget</a>, <a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>, <a href="http://people.skolelinux.org/pere/blog/tags/valg">valg</a>.
+ 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/video">video</a>.
</div>
<div class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Simpler_recipe_on_how_to_make_a_simple__7_IMSI_Catcher_using_Debian.html">Simpler recipe on how to make a simple $7 IMSI Catcher using Debian</a></div>
- <div class="date"> 9th August 2017</div>
- <div class="body"><p>On friday, I came across an interesting article in the Norwegian
-web based ICT news magazine digi.no on
-<a href="https://www.digi.no/artikler/sikkerhetsforsker-lagde-enkel-imsi-catcher-for-60-kroner-na-kan-mobiler-kartlegges-av-alle/398588">how
-to collect the IMSI numbers of nearby cell phones</a> using the cheap
-DVB-T software defined radios. The article refered to instructions
-and <a href="https://www.youtube.com/watch?v=UjwgNd_as30">a recipe by
-Keld Norman on Youtube on how to make a simple $7 IMSI Catcher</a>, and I decided to test them out.</p>
-
-<p>The instructions said to use Ubuntu, install pip using apt (to
-bypass apt), use pip to install pybombs (to bypass both apt and pip),
-and the ask pybombs to fetch and build everything you need from
-scratch. I wanted to see if I could do the same on the most recent
-Debian packages, but this did not work because pybombs tried to build
-stuff that no longer build with the most recent openssl library or
-some other version skew problem. While trying to get this recipe
-working, I learned that the apt->pip->pybombs route was a long detour,
-and the only piece of software dependency missing in Debian was the
-gr-gsm package. I also found out that the lead upstream developer of
-gr-gsm (the name stand for GNU Radio GSM) project already had a set of
-Debian packages provided in an Ubuntu PPA repository. All I needed to
-do was to dget the Debian source package and built it.</p>
-
-<p>The IMSI collector is a python script listening for packages on the
-loopback network device and printing to the terminal some specific GSM
-packages with IMSI numbers in them. The code is fairly short and easy
-to understand. The reason this work is because gr-gsm include a tool
-to read GSM data from a software defined radio like a DVB-T USB stick
-and other software defined radios, decode them and inject them into a
-network device on your Linux machine (using the loopback device by
-default). This proved to work just fine, and I've been testing the
-collector for a few days now.</p>
-
-<p>The updated and simpler recipe is thus to</p>
-
-<ol>
-
-<li>start with a Debian machine running Stretch or newer,</li>
-
-<li>build and install the gr-gsm package available from
-<a href="http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/">http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/</a>,</li>
-
-<li>clone the git repostory from <a href="https://github.com/Oros42/IMSI-catcher">https://github.com/Oros42/IMSI-catcher</a>,</li>
-
-<li>run grgsm_livemon and adjust the frequency until the terminal
-where it was started is filled with a stream of text (meaning you
-found a GSM station).</li>
-
-<li>go into the IMSI-catcher directory and run 'sudo python simple_IMSI-catcher.py' to extract the IMSI numbers.</li>
-
-</ol>
-
-<p>To make it even easier in the future to get this sniffer up and
-running, I decided to package
-<a href="https://github.com/ptrkrysik/gr-gsm/">the gr-gsm project</a>
-for Debian (<a href="https://bugs.debian.org/871055">WNPP
-#871055</a>), and the package was uploaded into the NEW queue today.
-Luckily the gnuradio maintainer has promised to help me, as I do not
-know much about gnuradio stuff yet.</p>
-
-<p>I doubt this "IMSI cacher" is anywhere near as powerfull as
-commercial tools like
-<a href="https://www.thespyphone.com/portable-imsi-imei-catcher/">The
-Spy Phone Portable IMSI / IMEI Catcher</a> or the
-<a href="https://en.wikipedia.org/wiki/Stingray_phone_tracker">Harris
-Stingray</a>, but I hope the existance of cheap alternatives can make
-more people realise how their whereabouts when carrying a cell phone
-is easily tracked. Seeing the data flow on the screen, realizing that
-I live close to a police station and knowing that the police is also
-wearing cell phones, I wonder how hard it would be for criminals to
-track the position of the police officers to discover when there are
-police near by, or for foreign military forces to track the location
-of the Norwegian military forces, or for anyone to track the location
-of government officials...</p>
-
-<p>It is worth noting that the data reported by the IMSI-catcher
-script mentioned above is only a fraction of the data broadcasted on
-the GSM network. It will only collect one frequency at the time,
-while a typical phone will be using several frequencies, and not all
-phones will be using the frequencies tracked by the grgsm_livemod
-program. Also, there is a lot of radio chatter being ignored by the
-simple_IMSI-catcher script, which would be collected by extending the
-parser code. I wonder if gr-gsm can be set up to listen to more than
-one frequency?</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/What_is_the_most_supported_MIME_type_in_Debian_in_2018_.html">What is the most supported MIME type in Debian in 2018?</a></div>
+ <div class="date"> 9th July 2018</div>
+ <div class="body"><p>Five years ago,
+<a href="http://people.skolelinux.org/pere/blog/What_is_the_most_supported_MIME_type_in_Debian_.html">I
+measured what the most supported MIME type in Debian was</a>, by
+analysing the desktop files in all packages in the archive. Since
+then, the DEP-11 AppStream system has been put into production, making
+the task a lot easier. This made me want to repeat the measurement,
+to see how much things changed. Here are the new numbers, for
+unstable only this time:
+
+<p><strong>Debian Unstable:</strong></p>
+
+<pre>
+ count MIME type
+ ----- -----------------------
+ 56 image/jpeg
+ 55 image/png
+ 49 image/tiff
+ 48 image/gif
+ 39 image/bmp
+ 38 text/plain
+ 37 audio/mpeg
+ 34 application/ogg
+ 33 audio/x-flac
+ 32 audio/x-mp3
+ 30 audio/x-wav
+ 30 audio/x-vorbis+ogg
+ 29 image/x-portable-pixmap
+ 27 inode/directory
+ 27 image/x-portable-bitmap
+ 27 audio/x-mpeg
+ 26 application/x-ogg
+ 25 audio/x-mpegurl
+ 25 audio/ogg
+ 24 text/html
+</pre>
+
+<p>The list was created like this using a sid chroot: "cat
+/var/lib/apt/lists/*sid*_dep11_Components-amd64.yml.gz| zcat | awk '/^
+- \S+\/\S+$/ {print $2 }' | sort | uniq -c | sort -nr | head -20"</p>
+
+<p>It is interesting to see how image formats have passed text/plain
+as the most announced supported MIME type. These days, thanks to the
+AppStream system, if you run into a file format you do not know, and
+want to figure out which packages support the format, you can find the
+MIME type of the file using "file --mime <filename>", and then
+look up all packages announcing support for this format in their
+AppStream metadata (XML or .desktop file) using "appstreamcli
+what-provides mimetype <mime-type>. For example if you, like
+me, want to know which packages support inode/directory, you can get a
+list like this:</p>
+
+<p><blockquote><pre>
+% appstreamcli what-provides mimetype inode/directory | grep Package: | sort
+Package: anjuta
+Package: audacious
+Package: baobab
+Package: cervisia
+Package: chirp
+Package: dolphin
+Package: doublecmd-common
+Package: easytag
+Package: enlightenment
+Package: ephoto
+Package: filelight
+Package: gwenview
+Package: k4dirstat
+Package: kaffeine
+Package: kdesvn
+Package: kid3
+Package: kid3-qt
+Package: nautilus
+Package: nemo
+Package: pcmanfm
+Package: pcmanfm-qt
+Package: qweborf
+Package: ranger
+Package: sirikali
+Package: spacefm
+Package: spacefm
+Package: vifm
+%
+</pre></blockquote></p>
+
+<p>Using the same method, I can quickly discover that the Sketchup file
+format is not yet supported by any package in Debian:</p>
+
+<p><blockquote><pre>
+% appstreamcli what-provides mimetype application/vnd.sketchup.skp
+Could not find component providing 'mimetype::application/vnd.sketchup.skp'.
+%
+</pre></blockquote></p>
+
+<p>Yesterday I used it to figure out which packages support the STL 3D
+format:</p>
+
+<p><blockquote><pre>
+% appstreamcli what-provides mimetype application/sla|grep Package
+Package: cura
+Package: meshlab
+Package: printrun
+%
+</pre></blockquote></p>
+
+<p>PS: A new version of Cura was uploaded to Debian yesterday.</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>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance</a>.
+ 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 class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Norwegian_Bokm_l_edition_of_Debian_Administrator_s_Handbook_is_now_available.html">Norwegian Bokmål edition of Debian Administrator's Handbook is now available</a></div>
- <div class="date">25th July 2017</div>
- <div class="body"><p align="center"><img align="center" src="http://people.skolelinux.org/pere/blog/images/2017-07-25-debian-handbook-nb-testprint.png"/></p>
-
-<p>I finally received a copy of the Norwegian Bokmål edition of
-"<a href="https://debian-handbook.info/">The Debian Administrator's
-Handbook</a>". This test copy arrived in the mail a few days ago, and
-I am very happy to hold the result in my hand. We spent around one and a half year translating it. This paperbook edition
-<a href="https://debian-handbook.info/get/#norwegian">is available
-from lulu.com</a>. If you buy it quickly, you save 25% on the list
-price. The book is also available for download in electronic form as
-PDF, EPUB and Mobipocket, as can be
-<a href="https://debian-handbook.info/browse/nb-NO/stable/">read online
-as a web page</a>.</p>
-
-<p>This is the second book I publish (the first was the book
-"<a href="http://free-culture.cc/">Free Culture</a>" by Lawrence Lessig
-in
-<a href="http://www.lulu.com/shop/lawrence-lessig/free-culture/paperback/product-22440520.html">English</a>,
-<a href="http://www.lulu.com/shop/lawrence-lessig/culture-libre/paperback/product-22645082.html">French</a>
-and
-<a href="http://www.lulu.com/shop/lawrence-lessig/fri-kultur/paperback/product-22441576.html">Norwegian
-Bokmål</a>), and I am very excited to finally wrap up this
-project. I hope
-"<a href="http://www.lulu.com/shop/rapha%C3%ABl-hertzog-and-roland-mas/h%C3%A5ndbok-for-debian-administratoren/paperback/product-23262290.html">Håndbok
-for Debian-administratoren</a>" will be well received.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Debian_APT_upgrade_without_enough_free_space_on_the_disk___.html">Debian APT upgrade without enough free space on the disk...</a></div>
+ <div class="date"> 8th July 2018</div>
+ <div class="body"><p>Quite regularly, I let my Debian Sid/Unstable chroot stay untouch
+for a while, and when I need to update it there is not enough free
+space on the disk for apt to do a normal 'apt upgrade'. I normally
+would resolve the issue by doing 'apt install <somepackages>' to
+upgrade only some of the packages in one batch, until the amount of
+packages to download fall below the amount of free space available.
+Today, I had about 500 packages to upgrade, and after a while I got
+tired of trying to install chunks of packages manually. I concluded
+that I did not have the spare hours required to complete the task, and
+decided to see if I could automate it. I came up with this small
+script which I call 'apt-in-chunks':</p>
+
+<p><blockquote><pre>
+#!/bin/sh
+#
+# Upgrade packages when the disk is too full to upgrade every
+# upgradable package in one lump. Fetching packages to upgrade using
+# apt, and then installing using dpkg, to avoid changing the package
+# flag for manual/automatic.
+
+set -e
+
+ignore() {
+ if [ "$1" ]; then
+ grep -v "$1"
+ else
+ cat
+ fi
+}
+
+for p in $(apt list --upgradable | ignore "$@" |cut -d/ -f1 | grep -v '^Listing...'); do
+ echo "Upgrading $p"
+ apt clean
+ apt install --download-only -y $p
+ for f in /var/cache/apt/archives/*.deb; do
+ if [ -e "$f" ]; then
+ dpkg -i /var/cache/apt/archives/*.deb
+ break
+ fi
+ done
+done
+</pre></blockquote></p>
+
+<p>The script will extract the list of packages to upgrade, try to
+download the packages needed to upgrade one package, install the
+downloaded packages using dpkg. The idea is to upgrade packages
+without changing the APT mark for the package (ie the one recording of
+the package was manually requested or pulled in as a dependency). To
+use it, simply run it as root from the command line. If it fail, try
+'apt install -f' to clean up the mess and run the script again. This
+might happen if the new packages conflict with one of the old
+packages. dpkg is unable to remove, while apt can do this.</p>
+
+<p>It take one option, a package to ignore in the list of packages to
+upgrade. The option to ignore a package is there to be able to skip
+the packages that are simply too large to unpack. Today this was
+'ghc', but I have run into other large packages causing similar
+problems earlier (like TeX).</p>
+
+<p>Update 2018-07-08: Thanks to Paul Wise, I am aware of two
+alternative ways to handle this. The "unattended-upgrades
+--minimal-upgrade-steps" option will try to calculate upgrade sets for
+each package to upgrade, and then upgrade them in order, smallest set
+first. It might be a better option than my above mentioned script.
+Also, "aptutude upgrade" can upgrade single packages, thus avoiding
+the need for using "dpkg -i" in the script above.</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/debian-handbook">debian-handbook</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
+ 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 class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/_Rapporten_ser_ikke_p__informasjonssikkerhet_knyttet_til_personlig_integritet_.html">«Rapporten ser ikke på informasjonssikkerhet knyttet til personlig integritet»</a></div>
- <div class="date">27th June 2017</div>
- <div class="body"><p>Jeg kom over teksten
-«<a href="https://freedom-to-tinker.com/2017/06/21/killing-car-privacy-by-federal-mandate/">Killing
-car privacy by federal mandate</a>» av Leonid Reyzin på Freedom to
-Tinker i dag, og det gleder meg å se en god gjennomgang om hvorfor det
-er et urimelig inngrep i privatsfæren å la alle biler kringkaste sin
-posisjon og bevegelse via radio. Det omtalte forslaget basert på
-Dedicated Short Range Communication (DSRC) kalles Basic Safety Message
-(BSM) i USA og Cooperative Awareness Message (CAM) i Europa, og det
-norske Vegvesenet er en av de som ser ut til å kunne tenke seg å
-pålegge alle biler å fjerne nok en bit av innbyggernes privatsfære.
-Anbefaler alle å lese det som står der.
-
-<p>Mens jeg tittet litt på DSRC på biler i Norge kom jeg over et sitat
-jeg synes er illustrativt for hvordan det offentlige Norge håndterer
-problemstillinger rundt innbyggernes privatsfære i SINTEF-rapporten
-«<a href="https://www.sintef.no/publikasjoner/publikasjon/Download/?pubid=SINTEF+A23933">Informasjonssikkerhet
-i AutoPASS-brikker</a>» av Trond Foss:</p>
-
-<p><blockquote>
-«Rapporten ser ikke på informasjonssikkerhet knyttet til personlig
- integritet.»
-</blockquote></p>
-
-<p>Så enkelt kan det tydeligvis gjøres når en vurderer
-informasjonssikkerheten. Det holder vel at folkene på toppen kan si
-at «Personvernet er ivaretatt», som jo er den populære intetsigende
-frasen som gjør at mange tror enkeltindividers integritet tas vare på.
-Sitatet fikk meg til å undres på hvor ofte samme tilnærming, å bare se
-bort fra behovet for personlig itegritet, blir valgt når en velger å
-legge til rette for nok et inngrep i privatsfæren til personer i
-Norge. Det er jo sjelden det får reaksjoner. Historien om
-reaksjonene på Helse Sør-Østs tjenesteutsetting er jo sørgelig nok et
-unntak og toppen av isfjellet, desverre. Tror jeg fortsatt takker nei
-til både AutoPASS og holder meg så langt unna det norske helsevesenet
-som jeg kan, inntil de har demonstrert og dokumentert at de verdsetter
-individets privatsfære og personlige integritet høyere enn kortsiktig
-gevist og samfunnsnytte.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/The_worlds_only_stone_power_plant_.html">The worlds only stone power plant?</a></div>
+ <div class="date">30th June 2018</div>
+ <div class="body"><p>So far, at least hydro-electric power, coal power, wind power,
+solar power, and wood power are well known. Until a few days ago, I
+had never heard of stone power. Then I learn about a quarry in a
+mountain in
+<a href="https://en.wikipedia.org/wiki/Bremanger">Bremanger</a> i
+Norway, where
+<a href="https://www.bontrup.com/en/activities/raw-materials/bremanger-quarry/">the
+Bremanger Quarry</a> company is extracting stone and dumping the stone
+into a shaft leading to its shipping harbour. This downward movement
+in this shaft is used to produce electricity. In short, it is using
+falling rocks instead of falling water to produce electricity, and
+according to its own statements it is producing more power than it is
+using, and selling the surplus electricity to the Norwegian power
+grid. I find the concept truly amazing. Is this the worlds only
+stone power plant?</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/norsk">norsk</a>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
</div>
<div class="padding"></div>
<div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Updated_sales_number_for_my_Free_Culture_paper_editions.html">Updated sales number for my Free Culture paper editions</a></div>
- <div class="date">12th June 2017</div>
- <div class="body"><p>It is pleasing to see that the work we put down in publishing new
-editions of the classic <a href="http://www.free-culture.cc/">Free
-Culture book</a> by the founder of the Creative Commons movement,
-Lawrence Lessig, is still being appreciated. I had a look at the
-latest sales numbers for the paper edition today. Not too impressive,
-but happy to see some buyers still exist. All the revenue from the
-books is sent to the <a href="https://creativecommons.org/">Creative
-Commons Corporation</a>, and they receive the largest cut if you buy
-directly from Lulu. Most books are sold via Amazon, with Ingram
-second and only a small fraction directly from Lulu. The ebook
-edition is available for free from
-<a href="https://github.com/petterreinholdtsen/free-culture-lessig">Github</a>.</p>
-
-<table border="0">
-<tr><th rowspan="2" valign="bottom">Title / language</th><th colspan="3">Quantity</th></tr>
-<tr><th>2016 jan-jun</th><th>2016 jul-dec</th><th>2017 jan-may</th></tr>
-
-<tr>
- <td><a href="http://www.lulu.com/shop/lawrence-lessig/culture-libre/paperback/product-22645082.html">Culture Libre / French</a></td>
- <td align="right">3</td>
- <td align="right">6</td>
- <td align="right">15</td>
-</tr>
-
-<tr>
- <td><a href="http://www.lulu.com/shop/lawrence-lessig/fri-kultur/paperback/product-22441576.html">Fri kultur / Norwegian</a></td>
- <td align="right">7</td>
- <td align="right">1</td>
- <td align="right">0</td>
-</tr>
-
-<tr>
- <td><a href="http://www.lulu.com/shop/lawrence-lessig/free-culture/paperback/product-22440520.html">Free Culture / English</a></td>
- <td align="right">14</td>
- <td align="right">27</td>
- <td align="right">16</td>
-</tr>
-
-<tr>
- <td>Total</td>
- <td align="right">24</td>
- <td align="right">34</td>
- <td align="right">31</td>
-</tr>
-
-</table>
-
-<p>A bit sad to see the low sales number on the Norwegian edition, and
-a bit surprising the English edition still selling so well.</p>
-
-<p>If you would like to translate and publish the book in your native
-language, I would be happy to help make it happen. Please get in
-touch.</p>
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Add_on_to_control_the_projector_from_within_Kodi.html">Add-on to control the projector from within Kodi</a></div>
+ <div class="date">26th June 2018</div>
+ <div class="body"><p>My movie playing setup involve <a href="https://kodi.tv/">Kodi</a>,
+<a href="https://openelec.tv">OpenELEC</a> (probably soon to be
+replaced with <a href="https://libreelec.tv/">LibreELEC</a>) and an
+Infocus IN76 video projector. My projector can be controlled via both
+a infrared remote controller, and a RS-232 serial line. The vendor of
+my projector, <a href="https://www.infocus.com/">InFocus</a>, had been
+sensible enough to document the serial protocol in its user manual, so
+it is easily available, and I used it some years ago to write
+<a href="https://github.com/petterreinholdtsen/infocus-projector-control">a
+small script to control the projector</a>. For a while now, I longed
+for a setup where the projector was controlled by Kodi, for example in
+such a way that when the screen saver went on, the projector was
+turned off, and when the screen saver exited, the projector was turned
+on again.</p>
+
+<p>A few days ago, with very good help from parts of my family, I
+managed to find a Kodi Add-on for controlling a Epson projector, and
+got in touch with its author to see if we could join forces and make a
+Add-on with support for several projectors. To my pleasure, he was
+positive to the idea, and we set out to add InFocus support to his
+add-on, and make the add-on suitable for the official Kodi add-on
+repository.</p>
+
+<p>The Add-on is now working (for me, at least), with a few minor
+adjustments. The most important change I do relative to the master
+branch in the github repository is embedding the
+<a href="https://github.com/pyserial/pyserial">pyserial module</a> in
+the add-on. The long term solution is to make a "script" type
+pyserial module for Kodi, that can be pulled in as a dependency in
+Kodi. But until that in place, I embed it.</p>
+
+<p>The add-on can be configured to turn on the projector when Kodi
+starts, off when Kodi stops as well as turn the projector off when the
+screensaver start and on when the screesaver stops. It can also be
+told to set the projector source when turning on the projector.
+
+<p>If this sound interesting to you, check out
+<a href="https://github.com/fredrik-eriksson/kodi_projcontrol">the
+project github repository</a>. Perhaps you can send patches to
+support your projector too? As soon as we find time to wrap up the
+latest changes, it should be available for easy installation using any
+Kodi instance.</p>
+
+<p>For future improvements, I would like to add projector model
+detection and the ability to adjust the brightness level of the
+projector from within Kodi. We also need to figure out how to handle
+the cooling period of the projector. My projector refuses to turn on
+for 60 seconds after it was turned off. This is not handled well by
+the add-on at the moment.</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/docbook">docbook</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture</a>.
+ Tags: <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>
<h2>Archive</h2>
<ul>
+<li>2018
+<ul>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/01/">January (1)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/02/">February (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/03/">March (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/04/">April (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/06/">June (2)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/07/">July (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2018/08/">August (3)</a></li>
+
+</ul></li>
+
<li>2017
<ul>
<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/09/">September (3)</a></li>
-<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/10/">October (3)</a></li>
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/10/">October (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/11/">November (3)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/12/">December (4)</a></li>
</ul></li>
<h2>Tags</h2>
<ul>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (14)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (16)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (9)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (16)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (17)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/bsa">bsa (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/chrpath">chrpath (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (154)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (161)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (158)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/dld">dld (17)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (24)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (25)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (355)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (382)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (12)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (13)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (30)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (32)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (9)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/intervju">intervju (42)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (15)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (16)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (20)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (9)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/lego">lego (4)</a></li>
+
<li><a href="http://people.skolelinux.org/pere/blog/tags/lenker">lenker (8)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/lsdvd">lsdvd (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network (8)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (39)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (41)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (9)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (10)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (293)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (299)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (189)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (190)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (33)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/open311">open311 (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (64)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (72)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (104)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (107)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (1)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/reactos">reactos (1)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (5)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (6)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (53)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (54)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (12)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (52)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (55)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (3)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/usenix">usenix (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/valg">valg (9)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (59)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/verkidetfri">verkidetfri (11)</a></li>
+
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (66)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (40)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (41)</a></li>
</ul>
projects / homepage.git / blobdiff