<link>http://people.skolelinux.org/pere/blog/</link>
<atom:link href="http://people.skolelinux.org/pere/blog/index.rss" rel="self" type="application/rss+xml" />
+ <item>
+ <title>Time for an official MIME type for patches?</title>
+ <link>http://people.skolelinux.org/pere/blog/Time_for_an_official_MIME_type_for_patches_.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Time_for_an_official_MIME_type_for_patches_.html</guid>
+ <pubDate>Thu, 1 Nov 2018 08:15:00 +0100</pubDate>
+ <description><p>As part of my involvement in
+<a href="https://gitlab.com/OsloMet-ABI/nikita-noark5-core">the Nikita
+archive API project</a>, I've been importing a fairly large lump of
+emails into a test instance of the archive to see how well this would
+go. I picked a subset of <a href="https://notmuchmail.org/">my
+notmuch email database</a>, all public emails sent to me via
+@lists.debian.org, giving me a set of around 216 000 emails to import.
+In the process, I had a look at the various attachments included in
+these emails, to figure out what to do with attachments, and noticed
+that one of the most common attachment formats do not have
+<a href="https://www.iana.org/assignments/media-types/media-types.xhtml">an
+official MIME type</a> registered with IANA/IETF. The output from
+diff, ie the input for patch, is on the top 10 list of formats
+included in these emails. At the moment people seem to use either
+text/x-patch or text/x-diff, but neither is officially registered. It
+would be better if one official MIME type were registered and used
+everywhere.</p>
+
+<p>To try to get one official MIME type for these files, I've brought
+up the topic on
+<a href="https://www.ietf.org/mailman/listinfo/media-types">the
+media-types mailing list</a>. If you are interested in discussion
+which MIME type to use as the official for patch files, or involved in
+making software using a MIME type for patches, perhaps you would like
+to join the discussion?</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>
+</description>
+ </item>
+
+ <item>
+ <title>Measuring the speaker frequency response using the AUDMES free software GUI - nice free software</title>
+ <link>http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html</guid>
+ <pubDate>Mon, 22 Oct 2018 08:40:00 +0200</pubDate>
+ <description><p><img src="http://people.skolelinux.org/pere/blog/images/2018-10-22-audmes-measure-speakers.png" align="right" width="40%"/></p>
+
+<p>My current home stereo is a patchwork of various pieces I got on
+flee markeds over the years. It is amazing what kind of equipment
+show up there. I've been wondering for a while if it was possible to
+measure how well this equipment is working together, and decided to
+see how far I could get using free software. After trawling the web I
+came across an article from DIY Audio and Video on
+<a href="https://www.diyaudioandvideo.com/Tutorial/SpeakerResponseTesting/">Speaker
+Testing and Analysis</a> describing how to test speakers, and it listing
+several software options, among them
+<a href="https://sourceforge.net/projects/audmes/">AUDio MEasurement
+System (AUDMES)</a>. It is the only free software system I could find
+focusing on measuring speakers and audio frequency response. In the
+process I also found an interesting article from NOVO on
+<a href="http://novo.press/understanding-speaker-specifications-and-frequency-response/">Understanding
+Speaker Specifications and Frequency Response</a> and an article from
+ecoustics on
+<a href="https://www.ecoustics.com/articles/understanding-speaker-frequency-response/">Understanding
+Speaker Frequency Response</a>, with a lot of information on what to
+look for and how to interpret the graphs. Armed with this knowledge,
+I set out to measure the state of my speakers.</p>
+
+<p>The first hurdle was that AUDMES hadn't seen a commit for 10 years
+and did not build with current compilers and libraries. I got in
+touch with its author, who no longer was spending time on the program
+but gave me write access to the subversion repository on Sourceforge.
+The end result is that now the code build on Linux and is capable of
+saving and loading the collected frequency response data in CSV
+format. The application is quite nice and flexible, and I was able to
+select the input and output audio interfaces independently. This made
+it possible to use a USB mixer as the input source, while sending
+output via my laptop headphone connection. I lacked the hardware and
+cabling to figure out a different way to get independent cabling to
+speakers and microphone.</p>
+
+<p>Using this setup I could see how a large range of high frequencies
+apparently were not making it out of my speakers. The picture show
+the frequency response measurement of one of the speakers. Note the
+frequency lines seem to be slightly misaligned, compared to the CSV
+output from the program. I can not hear several of these are high
+frequencies, according to measurement from
+<a href="http://freehearingtestsoftware.com">Free Hearing Test
+Software</a>, an freeware system to measure your hearing (still
+looking for a free software alternative), so I do not know if they are
+coming out out the speakers. I thus do not quite know how to figure
+out if the missing frequencies is a problem with the microphone, the
+amplifier or the speakers, but I managed to rule out the audio card in my
+PC by measuring my Bose noise canceling headset using its own
+microphone. This setup was able to see the high frequency tones, so
+the problem with my stereo had to be in the amplifier or speakers.</p>
+
+<p>Anyway, to try to role out one factor I ended up picking up a new
+set of speakers at a flee marked, and these work a lot better than the
+old speakers, so I guess the microphone and amplifier is OK. If you
+need to measure your own speakers, check out AUDMES. If more people
+get involved, perhaps the project could become good enough to
+<a href="https://bugs.debian.org/910876">include in Debian</a>? And if
+you know of some other free software to measure speakers and amplifier
+performance, please let me know. I am aware of the freeware option
+<a href="https://www.roomeqwizard.com/">REW</a>, but I want something
+that can be developed also when the vendor looses interest.</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>
+</description>
+ </item>
+
+ <item>
+ <title>Web browser integration of VLC with Bittorrent support</title>
+ <link>http://people.skolelinux.org/pere/blog/Web_browser_integration_of_VLC_with_Bittorrent_support.html</link>
+ <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Web_browser_integration_of_VLC_with_Bittorrent_support.html</guid>
+ <pubDate>Sun, 21 Oct 2018 09:50:00 +0200</pubDate>
+ <description><p>Bittorrent is as far as I know, currently the most efficient way to
+distribute content on the Internet. It is used all by all sorts of
+content providers, from national TV stations like
+<a href="https://www.nrk.no/">NRK</a>, Linux distributors like
+<a href="https://www.debian.org/">Debian</a> and
+<a href="https://www.ubuntu.com/">Ubuntu</a>, and of course the
+<a href="https://archive.org/">Internet archive</A>.
+
+<p>Almost a month ago
+<a href="https://tracker.debian.org/pkg/vlc-plugin-bittorrent">a new
+package adding Bittorrent support to VLC</a> became available in
+Debian testing and unstable. To test it, simply install it like
+this:</p>
+
+<p><pre>
+apt install vlc-plugin-bittorrent
+</pre></p>
+
+<p>Since the plugin was made available for the first time in Debian,
+several improvements have been made to it. In version 2.2-4, now
+available in both testing and unstable, a desktop file is provided to
+teach browsers to start VLC when the user click on torrent files or
+magnet links. The last part is thanks to me finally understanding
+what the strange x-scheme-handler style MIME types in desktop files
+are used for. By adding x-scheme-handler/magnet to the MimeType entry
+in the desktop file, at least the browsers Firefox and Chromium will
+suggest to start VLC when selecting a magnet URI on a web page. The
+end result is that now, with the plugin installed in Buster and Sid,
+one can visit any
+<a href="https://archive.org/details/CopyingIsNotTheft1080p">Internet
+Archive page with movies</a> using a web browser and click on the
+torrent link to start streaming the movie.</p>
+
+<p>Note, there is still some misfeatures in the plugin. One is the
+fact that it will hang and
+<a href="https://github.com/johang/vlc-bittorrent/issues/13">block VLC
+from exiting until the torrent streaming starts</a>. Another is the
+fact that it
+<a href="https://github.com/johang/vlc-bittorrent/issues/9">will pick
+and play a random file in a multi file torrent</a>. This is not
+always the video file you want. Combined with the first it can be a
+bit hard to get the video streaming going. But when it work, it seem
+to do a good job.</p>
+
+<p>For the Debian packaging, I would love to find a good way to test
+if the plugin work with VLC using autopkgtest. I tried, but do not
+know enough of the inner workings of VLC to get it working. For now
+the autopkgtest script is only checking if the .so file was
+successfully loaded by VLC. If you have any suggestions, please
+submit a patch to the Debian bug tracking system.</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>
+</description>
+ </item>
+
<item>
<title>Release 0.2 of free software archive system Nikita announced</title>
<link>http://people.skolelinux.org/pere/blog/Release_0_2_of_free_software_archive_system_Nikita_announced.html</link>
</description>
</item>
- <item>
- <title>A bit more on privacy respecting health monitor / fitness tracker</title>
- <link>http://people.skolelinux.org/pere/blog/A_bit_more_on_privacy_respecting_health_monitor___fitness_tracker.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/A_bit_more_on_privacy_respecting_health_monitor___fitness_tracker.html</guid>
- <pubDate>Mon, 13 Aug 2018 09:00:00 +0200</pubDate>
- <description><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>
-</description>
- </item>
-
- <item>
- <title>Privacy respecting health monitor / fitness tracker?</title>
- <link>http://people.skolelinux.org/pere/blog/Privacy_respecting_health_monitor___fitness_tracker_.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Privacy_respecting_health_monitor___fitness_tracker_.html</guid>
- <pubDate>Tue, 7 Aug 2018 16:00:00 +0200</pubDate>
- <description><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>
-</description>
- </item>
-
- <item>
- <title>Sharing images with friends and family using RSS and EXIF/XMP metadata</title>
- <link>http://people.skolelinux.org/pere/blog/Sharing_images_with_friends_and_family_using_RSS_and_EXIF_XMP_metadata.html</link>
- <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Sharing_images_with_friends_and_family_using_RSS_and_EXIF_XMP_metadata.html</guid>
- <pubDate>Tue, 31 Jul 2018 23:30:00 +0200</pubDate>
- <description><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
-&lt;enclosure&gt; 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>
-</description>
- </item>
-
</channel>
</rss>
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