X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/aaf3a8d6ac3f87b3060fda22f11cb474d2e37af0..162b054d8dd0d79ca99380bae4c82b4512ea7a2d:/blog/index.rss diff --git a/blog/index.rss b/blog/index.rss index 317126122a..085c7f3828 100644 --- a/blog/index.rss +++ b/blog/index.rss @@ -6,6 +6,369 @@ http://people.skolelinux.org/pere/blog/ + + CasparCG Server for TV broadcast playout in Debian + http://people.skolelinux.org/pere/blog/CasparCG_Server_for_TV_broadcast_playout_in_Debian.html + http://people.skolelinux.org/pere/blog/CasparCG_Server_for_TV_broadcast_playout_in_Debian.html + Tue, 15 Jan 2019 00:10:00 +0100 + <p>The layered video playout server created by Sveriges Television, +<a href="https://casparcg.com/">CasparCG Server</a>, entered Debian +today. This completes many months of work to get the source ready to +go into Debian. The first upload to the Debian NEW queue happened a +month ago, but the work upstream to prepare it for Debian started more +than two and a half month ago. So far +<a href="https://tracker.debian.org/pkg/casparcg-server">the +casparcg-server package</a> is only available for amd64, but I hope +this can be improved. The package is in contrib because it depend on +the <a href="https://tracker.debian.org/pkg/fdk-aac">non-free fdk-aac +library</a>. The Debian package lack support for streaming web pages +because Debian is missing CEF, Chromium Embedded Framework. CEF is +wanted by several packages in Debian. But because the Chromium source +is <a href="https://bugs.debian.org/893448">not available as a build +dependency</a>, it is not yet possible to upload CEF to Debian. I +hope this will change in the future.</p> + +<p>The reason I got involved is that +<a href="https://frikanalen.no/">the Norwegian open channel +Frikanalen</a> is starting to use CasparCG for our HD playout, and I +would like to have all the free software tools we use to run the TV +channel available as packages from the Debian project. The last +remaining piece in the puzzle is Open Broadcast Encoder, but it depend +on quite a lot of patched libraries which would have to be included in +Debian first.</p> + + + + + Learn to program with Minetest on Debian + http://people.skolelinux.org/pere/blog/Learn_to_program_with_Minetest_on_Debian.html + http://people.skolelinux.org/pere/blog/Learn_to_program_with_Minetest_on_Debian.html + Sat, 15 Dec 2018 15:30:00 +0100 + <p>A fun way to learn how to program +<a href="https://www.python.org/">Python</a> is to follow the +instructions in the book +"<a href="https://nostarch.com/programwithminecraft">Learn to program +with Minecraft</a>", which introduces programming in Python to people +who like to play with Minecraft. The book uses a Python library to +talk to a TCP/IP socket with an API accepting build instructions and +providing information about the current players in a Minecraft world. +The TCP/IP API was first created for the Minecraft implementation for +Raspberry Pi, and has since been ported to some server versions of +Minecraft. The book contain recipes for those using Windows, MacOSX +and Raspian. But a little known fact is that you can follow the same +recipes using the free software construction game +<a href="https://minetest.net/">Minetest</a>.</p> + +<p>There is <a href="https://github.com/sprintingkiwi/pycraft_mod">a +Minetest module implementing the same API</a>, making it possible to +use the Python programs coded to talk to Minecraft with Minetest too. +I +<a href="https://ftp-master.debian.org/new/minetest-mod-pycraft_0.20%2Bgit20180331.0376a0a%2Bdfsg-1.html">uploaded +this module</a> to Debian two weeks ago, and as soon as it clears the +FTP masters NEW queue, learning to program Python with Minetest on +Debian will be a simple 'apt install' away. The Debian package is +maintained as part of the Debian Games team, and +<a href="https://salsa.debian.org/games-team/unfinished/minetest-mod-pycraft">the +packaging rules</a> are currently located under 'unfinished' on +Salsa.</p> + +<p>You will most likely need to install several of the Minetest +modules in Debian for the examples included with the library to work +well, as there are several blocks used by the example scripts that are +provided via modules in Minetest. Without the required blocks, a +simple stone block is used instead. My initial testing with a analog +clock did not get gold arms as instructed in the python library, but +instead used stone arms.</p> + +<p>I tried to find a way to add the API to the desktop version of +Minecraft, but were unable to find any working recipes. The +<a href="https://www.epiphanydigest.com/tag/minecraft-python-api/">recipes</a> +I <a href="https://github.com/kbsriram/mcpiapi">found</a> are only +working with a standalone Minecraft server setup. Are there any +options to use with the normal desktop version?</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> + + + + + Non-blocking bittorrent plugin for vlc + http://people.skolelinux.org/pere/blog/Non_blocking_bittorrent_plugin_for_vlc.html + http://people.skolelinux.org/pere/blog/Non_blocking_bittorrent_plugin_for_vlc.html + Wed, 12 Dec 2018 07:20:00 +0100 + <p>A few hours ago, a new and improved version (2.4) of +<a href="https://tracker.debian.org/pkg/vlc-plugin-bittorrent">the VLC +bittorrent plugin</a> was uploaded to Debian. This new version +include a complete rewrite of the bittorrent related code, which seem +to make the plugin non-blocking. This mean you can actually exit VLC +even when the plugin seem to be unable to get the bittorrent streaming +started. The new version also include support for filtering playlist +by file extension using command line options, if you want to avoid +processing audio, video or images. The package is currently in Debian +unstable, but should be available in Debian testing in two days. To +test it, simply install it like this:</p> + +<p><pre> +apt install vlc-plugin-bittorrent +</pre></p> + +<p>After it is installed, you can try to use it to play a file +downloaded live via bittorrent like this: + +<p><pre> +vlc https://archive.org/download/Glass_201703/Glass_201703_archive.torrent +</pre></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> + + + + + Retten til kontant betaling er en rettighet som må brukes for å beholdes + http://people.skolelinux.org/pere/blog/Retten_til_kontant_betaling_er_en_rettighet_som_m__brukes_for___beholdes.html + http://people.skolelinux.org/pere/blog/Retten_til_kontant_betaling_er_en_rettighet_som_m__brukes_for___beholdes.html + Tue, 11 Dec 2018 10:00:00 +0100 + <p><a href="https://www.fn.no/Om-FN/Avtaler/Menneskerettigheter/FNs-verdenserklaering-om-menneskerettigheter">FNs +menneskerettighetserklæring</a> artikkel 13 første punkt lyder som +følger:</p> + +<p><blockquote> +Enhver har rett til å bevege seg fritt og til fritt å velge +oppholdssted innenfor en stats grenser. +</blockquote></p> + +<p>Det er altså en menneskerett å kunne bevege seg fritt i landet. +For å bevege seg fritt i landet, så må en kunne bevege seg uten å bli +sporet. Det vil i dagens samfunn innebære å bevege seg uten å legge +igjen digitale spor og uten å være radiomerket. Hvis en vet at ens +bevegelser, hvor en befinner seg når, og hvem som befinner seg i +nærheten, blir samlet inn og gjort tilgjengelig for fremmede, det være +seg myndighetene eller private organisasjoner, så kan en ikke lenger +bevege seg fritt. Dette gjør at det er en forutsetning for å ha glede +av retten til å bevege seg fritt i landet at en motstår fristelsen til +å legge igjen digitale spor når en betaler for seg. Rettigheter som +ikke blir brukt, blir fjernet. Den eneste måten i dag å unngå å legge +igjen digitale spor når en betaler for seg, er å betale med kontanter, +samt takke nei til å legge igjen navn og adresse (slik f.eks. Elkjøp +ber om &mdash; jeg sier de kan legge inn «anonym anonym» når +datasystemet deres trenger et navn). Personlig anbefaler jeg å +konsekvent bruke kontant betaling når man beveger seg rundt, for å +bidra til forsvaret av menneskerettighetene i Norge. Kanskje noe også +for deg? Merk at det ikke er tilstrekkelig for å unngå sporing å +betale med kontanter, men det er et lite steg i riktig retning.</p> + +<p>Det er flere andre argumenter i tillegg til +menneskerettighetsargumentet for å bruke kontanter. I går hadde +Dagbladet en utmerket kommentar av sin journalist John Olav Egeland om +hvilket +<a href="https://www.dagbladet.no/kultur/kontantlost-diktatur/70543434">kontantløst +diktatur</a> som venter oss hvis mange nok slutter å insistere på å +betale med kontanter. Jeg anbefaler deg å lese den.</p> + +<p>Som vanlig, hvis du bruker Bitcoin og ønsker å vise din støtte til +det jeg driver med, setter jeg pris på om du sender Bitcoin-donasjoner +til min adresse +<b><a href="bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b">15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b</a></b>. +Merk, betaling med bitcoin er ikke anonymt. :)</p> + + + + + Why is your site not using Content Security Policy / CSP? + http://people.skolelinux.org/pere/blog/Why_is_your_site_not_using_Content_Security_Policy___CSP_.html + http://people.skolelinux.org/pere/blog/Why_is_your_site_not_using_Content_Security_Policy___CSP_.html + Sun, 9 Dec 2018 15:00:00 +0100 + <p>Yesterday, I had the pleasure of watching on Frikanalen the OWASP +talk by Scott Helme titled +"<a href="https://frikanalen.no/video/626080/">What We’ve Learned From +Billions of Security Reports</a>". I had not heard of the +<a href="https://en.wikipedia.org/wiki/Content_Security_Policy">Content +Security Policy standard</a> nor its ability to "call home" when a +browser detect a policy breach (I do not follow web page design +development much these days), and found the talk very illuminating.</p> + +<p>The mechanism allow a web site owner to use HTTP headers to tell +visitors web browser which sources (internal and external) are allowed to +be used on the web site. Thus it become possible to enforce a "only +local content" policy despite web designers urge to fetch programs +from random sites on the Internet, like the one +<a href="https://securityaffairs.co/wordpress/68966/hacking/browsealoud-plugin-hack.html">enabling +the attack</a> reported by Scott Helme earlier this year.</p> + +<p>Using CSP seem like an obvious thing for a site admin to implement +to take some control over the information leak that occur when +external sources are used to render web pages, it is a mystery more +sites are not using CSP? It is being +<a href="https://www.w3.org/TR/CSP/">standardized under W3C</a> these +days, and is supposed by most web browsers</p> + +<p>I managed to find <a href="https://github.com/mozilla/django-csp">a +Django middleware for implementing CSP</a> and was happy to discover +it was already in Debian. I plan to use it to add CSP support to the +Frikanalen web site soon.</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> + + + + + New and improved Frikanalen Kodi addon version 0.0.3 + http://people.skolelinux.org/pere/blog/New_and_improved_Frikanalen_Kodi_addon_version_0_0_3.html + http://people.skolelinux.org/pere/blog/New_and_improved_Frikanalen_Kodi_addon_version_0_0_3.html + Thu, 8 Nov 2018 10:30:00 +0100 + <p>If you read my blog regularly, you probably know I am involved in +running and developing the <a href="https://frikanalen.no/">Norwegian +TV channel Frikanalen</a>. It is an open channel, allowing everyone +in Norway to publish videos on a TV channel with national coverage. +You can think of it as Youtube for national television. +In addition to distribution on RiksTV and Uninett, Frikanalen is also +available as a Kodi addon. The last few days I have updated the code +to add more features. A +<a href="https://kodi.tv/addon/plugins-video-add-ons/frikanalen-nett-tv">new +and improved version 0.0.3 Frikanalen addon</a> was just made +available via the Kodi repositories. This new version include a +option to browse videos by category, as well as free text search +in the video archive. It will now also show the video duration in the +video lists, which were missing earlier. A new and experimental +link to the HD video stream currently being worked on is provided, for +those that want to see what the <a href="https://casparcg.com/">CasparCG</a> +output look like. The alternative is the SD video stream, generated +using MLT. CasparCG is controlled by our +<a href="https://github.com/Frikanalen/mltplayout/">mltplayout +server</a> which instead of talking to mlt is giving PLAY instructions +to the CasparCG server when it is time to start a new program.</p> + +<p>By now, you are probably wondering what kind of content is being +played on the channel. These days, it is filled with technical +presentations like those from <a href="https://www.nuug.no/">NUUG</a>, +<a href="https://www.debconf.org/">Debconf</a>, Makercon, and TED, +but there are also some periods with +<a href="https://www.empo.no/">EMPT TV</a> and +<a href="https://www.p7.no/">P7</a>. + +<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> + + + + + Time for an official MIME type for patches? + http://people.skolelinux.org/pere/blog/Time_for_an_official_MIME_type_for_patches_.html + http://people.skolelinux.org/pere/blog/Time_for_an_official_MIME_type_for_patches_.html + Thu, 1 Nov 2018 08:15:00 +0100 + <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> + + + + + Measuring the speaker frequency response using the AUDMES free software GUI - nice free software + http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html + http://people.skolelinux.org/pere/blog/Measuring_the_speaker_frequency_response_using_the_AUDMES_free_software_GUI___nice_free_software.html + Mon, 22 Oct 2018 08:40:00 +0200 + <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> + + + Web browser integration of VLC with Bittorrent support http://people.skolelinux.org/pere/blog/Web_browser_integration_of_VLC_with_Bittorrent_support.html @@ -38,7 +401,7 @@ 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 og Sid, +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 @@ -137,514 +500,6 @@ irc.freenode.net</a>) or email (<a href="https://lists.nuug.no/mailman/listinfo/nikita-noark">nikita-noark mailing list</a>).</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> - - - - - Fetching trusted timestamps using the rfc3161ng python module - http://people.skolelinux.org/pere/blog/Fetching_trusted_timestamps_using_the_rfc3161ng_python_module.html - http://people.skolelinux.org/pere/blog/Fetching_trusted_timestamps_using_the_rfc3161ng_python_module.html - Mon, 8 Oct 2018 12:30:00 +0200 - <p>I have earlier covered the basics of trusted timestamping using the -'openssl ts' client. See blog post for -<a href="http://people.skolelinux.org/pere/blog/Public_Trusted_Timestamping_services_for_everyone.html">2014</a>, -<a href="http://people.skolelinux.org/pere/blog/syslog_trusted_timestamp___chain_of_trusted_timestamps_for_your_syslog.html">2016</a> -and -<a href="http://people.skolelinux.org/pere/blog/Idea_for_storing_trusted_timestamps_in_a_Noark_5_archive.html">2017</a> -for those stories. But some times I want to integrate the timestamping -in other code, and recently I needed to integrate it into Python. -After searching a bit, I found -<a href="https://dev.entrouvert.org/projects/python-rfc3161">the -rfc3161 library</a> which seemed like a good fit, but I soon -discovered it only worked for python version 2, and I needed something -that work with python version 3. Luckily I next came across -<a href="https://github.com/trbs/rfc3161ng/">the rfc3161ng library</a>, -a fork of the original rfc3161 library. Not only is it working with -python 3, it have fixed a few of the bugs in the original library, and -it has an active maintainer. I decided to wrap it up and make it -<a href="https://tracker.debian.org/pkg/python-rfc3161ng">available in -Debian</a>, and a few days ago it entered Debian unstable and testing.</p> - -<p>Using the library is fairly straight forward. The only slightly -problematic step is to fetch the required certificates to verify the -timestamp. For some services it is straight forward, while for others -I have not yet figured out how to do it. Here is a small standalone -code example based on of the integration tests in the library code:</p> - -<pre> -#!/usr/bin/python3 - -""" - -Python 3 script demonstrating how to use the rfc3161ng module to -get trusted timestamps. - -The license of this code is the same as the license of the rfc3161ng -library, ie MIT/BSD. - -""" - -import os -import pyasn1.codec.der -import rfc3161ng -import subprocess -import tempfile -import urllib.request - -def store(f, data): - f.write(data) - f.flush() - f.seek(0) - -def fetch(url, f=None): - response = urllib.request.urlopen(url) - data = response.read() - if f: - store(f, data) - return data - -def main(): - with tempfile.NamedTemporaryFile() as cert_f,\ - tempfile.NamedTemporaryFile() as ca_f,\ - tempfile.NamedTemporaryFile() as msg_f,\ - tempfile.NamedTemporaryFile() as tsr_f: - - # First fetch certificates used by service - certificate_data = fetch('https://freetsa.org/files/tsa.crt', cert_f) - ca_data_data = fetch('https://freetsa.org/files/cacert.pem', ca_f) - - # Then timestamp the message - timestamper = \ - rfc3161ng.RemoteTimestamper('http://freetsa.org/tsr', - certificate=certificate_data) - data = b"Python forever!\n" - tsr = timestamper(data=data, return_tsr=True) - - # Finally, convert message and response to something 'openssl ts' can verify - store(msg_f, data) - store(tsr_f, pyasn1.codec.der.encoder.encode(tsr)) - args = ["openssl", "ts", "-verify", - "-data", msg_f.name, - "-in", tsr_f.name, - "-CAfile", ca_f.name, - "-untrusted", cert_f.name] - subprocess.check_call(args) - -if '__main__' == __name__: - main() -</pre> - -<p>The code fetches the required certificates, store them as temporary -files, timestamp a simple message, store the message and timestamp to -disk and ask 'openssl ts' to verify the timestamp. A timestamp is -around 1.5 kiB in size, and should be fairly easy to store for future -use.</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> - - - - - Automatic Google Drive sync using grive in Debian - http://people.skolelinux.org/pere/blog/Automatic_Google_Drive_sync_using_grive_in_Debian.html - http://people.skolelinux.org/pere/blog/Automatic_Google_Drive_sync_using_grive_in_Debian.html - Thu, 4 Oct 2018 15:20:00 +0200 - <p>A few days, I rescued a Windows victim over to Debian. To try to -rescue the remains, I helped set up automatic sync with Google Drive. -I did not find any sensible Debian package handling this -automatically, so I rebuild the grive2 source from -<a href="http://www.webupd8.org/">the Ubuntu UPD8 PPA</a> to do the -task and added a autostart desktop entry and a small shell script to -run in the background while the user is logged in to do the sync. -Here is a sketch of the setup for future reference.</p> - -<p>I first created <tt>~/googledrive</tt>, entered the directory and -ran '<tt>grive -a</tt>' to authenticate the machine/user. Next, I -created a autostart hook in <tt>~/.config/autostart/grive.desktop</tt> -to start the sync when the user log in:</p> - -<p><blockquote><pre> -[Desktop Entry] -Name=Google drive autosync -Type=Application -Exec=/home/user/bin/grive-sync -</pre></blockquote></p> - -<p>Finally, I wrote the <tt>~/bin/grive-sync</tt> script to sync -~/googledrive/ with the files in Google Drive.</p> - -<p><blockquote><pre> -#!/bin/sh -set -e -cd ~/ -cleanup() { - if [ "$syncpid" ] ; then - kill $syncpid - fi -} -trap cleanup EXIT INT QUIT -/usr/lib/grive/grive-sync.sh listen googledrive 2>&1 | sed "s%^%$0:%" & -syncpdi=$! -while true; do - if ! xhost >/dev/null 2>&1 ; then - echo "no DISPLAY, exiting as the user probably logged out" - exit 1 - fi - if [ ! -e /run/user/1000/grive-sync.sh_googledrive ] ; then - /usr/lib/grive/grive-sync.sh sync googledrive - fi - sleep 300 -done 2>&1 | sed "s%^%$0:%" -</pre></blockquote></p> - -<p>Feel free to use the setup if you want. It can be assumed to be -GNU GPL v2 licensed (or any later version, at your leisure), but I -doubt this code is possible to claim copyright on.</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> - - - - - Valutakrambod - A python and bitcoin love story - http://people.skolelinux.org/pere/blog/Valutakrambod___A_python_and_bitcoin_love_story.html - http://people.skolelinux.org/pere/blog/Valutakrambod___A_python_and_bitcoin_love_story.html - Sat, 29 Sep 2018 22:20:00 +0200 - <p>It would come as no surprise to anyone that I am interested in -bitcoins and virtual currencies. I've been keeping an eye on virtual -currencies for many years, and it is part of the reason a few months -ago, I started writing a python library for collecting currency -exchange rates and trade on virtual currency exchanges. I decided to -name the end result valutakrambod, which perhaps can be translated to -small currency shop.</p> - -<p>The library uses the tornado python library to handle HTTP and -websocket connections, and provide a asynchronous system for -connecting to and tracking several services. The code is available -from -<a href="http://github.com/petterreinholdtsen/valutakrambod">github</a>.</p> - -</p>There are two example clients of the library. One is very simple and -list every updated buy/sell price received from the various services. -This code is started by running bin/btc-rates and call the client code -in valutakrambod/client.py. The simple client look like this:</p> - -<p><blockquote><pre> -import functools -import tornado.ioloop -import valutakrambod -class SimpleClient(object): - def __init__(self): - self.services = [] - self.streams = [] - pass - def newdata(self, service, pair, changed): - print("%-15s %s-%s: %8.3f %8.3f" % ( - service.servicename(), - pair[0], - pair[1], - service.rates[pair]['ask'], - service.rates[pair]['bid']) - ) - async def refresh(self, service): - await service.fetchRates(service.wantedpairs) - def run(self): - self.ioloop = tornado.ioloop.IOLoop.current() - self.services = valutakrambod.service.knownServices() - for e in self.services: - service = e() - service.subscribe(self.newdata) - stream = service.websocket() - if stream: - self.streams.append(stream) - else: - # Fetch information from non-streaming services immediately - self.ioloop.call_later(len(self.services), - functools.partial(self.refresh, service)) - # as well as regularly - service.periodicUpdate(60) - for stream in self.streams: - stream.connect() - try: - self.ioloop.start() - except KeyboardInterrupt: - print("Interrupted by keyboard, closing all connections.") - pass - for stream in self.streams: - stream.close() -</pre></blockquote></p> - -<p>The library client loops over all known "public" services, -initialises it, subscribes to any updates from the service, checks and -activates websocket streaming if the service provide it, and if no -streaming is supported, fetches information from the service and sets -up a periodic update every 60 seconds. The output from this client -can look like this:</p> - -<p><blockquote><pre> -Bl3p BTC-EUR: 5687.110 5653.690 -Bl3p BTC-EUR: 5687.110 5653.690 -Bl3p BTC-EUR: 5687.110 5653.690 -Hitbtc BTC-USD: 6594.560 6593.690 -Hitbtc BTC-USD: 6594.560 6593.690 -Bl3p BTC-EUR: 5687.110 5653.690 -Hitbtc BTC-USD: 6594.570 6593.690 -Bitstamp EUR-USD: 1.159 1.154 -Hitbtc BTC-USD: 6594.570 6593.690 -Hitbtc BTC-USD: 6594.580 6593.690 -Hitbtc BTC-USD: 6594.580 6593.690 -Hitbtc BTC-USD: 6594.580 6593.690 -Bl3p BTC-EUR: 5687.110 5653.690 -Paymium BTC-EUR: 5680.000 5620.240 -</pre></blockquote></p> - -<p>The exchange order book is tracked in addition to the best buy/sell -price, for those that need to know the details.</p> - -<p>The other example client is focusing on providing a curses view -with updated buy/sell prices as soon as they are received from the -services. This code is located in bin/btc-rates-curses and activated -by using the '-c' argument. Without the argument the "curses" output -is printed without using curses, which is useful for debugging. The -curses view look like this:</p> - -<p><blockquote><pre> - Name Pair Bid Ask Spr Ftcd Age - BitcoinsNorway BTCEUR 5591.8400 5711.0800 2.1% 16 nan 60 - Bitfinex BTCEUR 5671.0000 5671.2000 0.0% 16 22 59 - Bitmynt BTCEUR 5580.8000 5807.5200 3.9% 16 41 60 - Bitpay BTCEUR 5663.2700 nan nan% 15 nan 60 - Bitstamp BTCEUR 5664.8400 5676.5300 0.2% 0 1 1 - Bl3p BTCEUR 5653.6900 5684.9400 0.5% 0 nan 19 - Coinbase BTCEUR 5600.8200 5714.9000 2.0% 15 nan nan - Kraken BTCEUR 5670.1000 5670.2000 0.0% 14 17 60 - Paymium BTCEUR 5620.0600 5680.0000 1.1% 1 7515 nan - BitcoinsNorway BTCNOK 52898.9700 54034.6100 2.1% 16 nan 60 - Bitmynt BTCNOK 52960.3200 54031.1900 2.0% 16 41 60 - Bitpay BTCNOK 53477.7833 nan nan% 16 nan 60 - Coinbase BTCNOK 52990.3500 54063.0600 2.0% 15 nan nan - MiraiEx BTCNOK 52856.5300 54100.6000 2.3% 16 nan nan - BitcoinsNorway BTCUSD 6495.5300 6631.5400 2.1% 16 nan 60 - Bitfinex BTCUSD 6590.6000 6590.7000 0.0% 16 23 57 - Bitpay BTCUSD 6564.1300 nan nan% 15 nan 60 - Bitstamp BTCUSD 6561.1400 6565.6200 0.1% 0 2 1 - Coinbase BTCUSD 6504.0600 6635.9700 2.0% 14 nan 117 - Gemini BTCUSD 6567.1300 6573.0700 0.1% 16 89 nan - Hitbtc+BTCUSD 6592.6200 6594.2100 0.0% 0 0 0 - Kraken BTCUSD 6565.2000 6570.9000 0.1% 15 17 58 - Exchangerates EURNOK 9.4665 9.4665 0.0% 16 107789 nan - Norgesbank EURNOK 9.4665 9.4665 0.0% 16 107789 nan - Bitstamp EURUSD 1.1537 1.1593 0.5% 4 5 1 - Exchangerates EURUSD 1.1576 1.1576 0.0% 16 107789 nan - BitcoinsNorway LTCEUR 1.0000 49.0000 98.0% 16 nan nan - BitcoinsNorway LTCNOK 492.4800 503.7500 2.2% 16 nan 60 - BitcoinsNorway LTCUSD 1.0221 49.0000 97.9% 15 nan nan - Norgesbank USDNOK 8.1777 8.1777 0.0% 16 107789 nan -</pre></blockquote></p> - -<p>The code for this client is too complex for a simple blog post, so -you will have to check out the git repository to figure out how it -work. What I can tell is how the three last numbers on each line -should be interpreted. The first is how many seconds ago information -was received from the service. The second is how long ago, according -to the service, the provided information was updated. The last is an -estimate on how often the buy/sell values change.</p> - -<p>If you find this library useful, or would like to improve it, I -would love to hear from you. Note that for some of the services I've -implemented a trading API. It might be the topic of a future blog -post.</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> - - - - - VLC in Debian now can do bittorrent streaming - http://people.skolelinux.org/pere/blog/VLC_in_Debian_now_can_do_bittorrent_streaming.html - http://people.skolelinux.org/pere/blog/VLC_in_Debian_now_can_do_bittorrent_streaming.html - Mon, 24 Sep 2018 21:20:00 +0200 - <p>Back in February, I got curious to see -<a href="http://people.skolelinux.org/pere/blog/Using_VLC_to_stream_bittorrent_sources.html">if -VLC now supported Bittorrent streaming</a>. It did not, despite the -fact that the idea and code to handle such streaming had been floating -around for years. I did however find -<a href="https://github.com/johang/vlc-bittorrent">a standalone plugin -for VLC</a> to do it, and half a year later I decided to wrap up the -plugin and get it into Debian. I uploaded it to NEW a few days ago, -and am very happy to report that it -<a href="https://tracker.debian.org/pkg/vlc-plugin-bittorrent">entered -Debian</a> a few hours ago, and should be available in Debian/Unstable -tomorrow, and Debian/Testing in a few days.</p> - -<p>With the vlc-plugin-bittorrent package installed you should be able -to stream videos using a simple call to</p> - -<p><blockquote><pre> -vlc https://archive.org/download/TheGoat/TheGoat_archive.torrent -</pre></blockquote></p> - -</p>It can handle magnet links too. Now if only native vlc had -bittorrent support. Then a lot more would be helping each other to -share public domain and creative commons movies. The plugin need some -stability work with seeking and picking the right file in a torrent -with many files, but is already usable. Please note that the plugin -is not removing downloaded files when vlc is stopped, so it can fill -up your disk if you are not careful. Have fun. :)</p> - -<p>I would love to get help maintaining this package. Get in touch if -you are interested.</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> - - - - - Using the Kodi API to play Youtube videos - http://people.skolelinux.org/pere/blog/Using_the_Kodi_API_to_play_Youtube_videos.html - http://people.skolelinux.org/pere/blog/Using_the_Kodi_API_to_play_Youtube_videos.html - Sun, 2 Sep 2018 23:40:00 +0200 - <p>I continue to explore my Kodi installation, and today I wanted to -tell it to play a youtube URL I received in a chat, without having to -insert search terms using the on-screen keyboard. After searching the -web for API access to the Youtube plugin and testing a bit, I managed -to find a recipe that worked. If you got a kodi instance with its API -available from http://kodihost/jsonrpc, you can try the following to -have check out a nice cover band.</p> - -<p><blockquote><pre>curl --silent --header 'Content-Type: application/json' \ - --data-binary '{ "id": 1, "jsonrpc": "2.0", "method": "Player.Open", - "params": {"item": { "file": - "plugin://plugin.video.youtube/play/?video_id=LuRGVM9O0qg" } } }' \ - http://projector.local/jsonrpc</pre></blockquote></p> - -<p>I've extended kodi-stream program to take a video source as its -first argument. It can now handle direct video links, youtube links -and 'desktop' to stream my desktop to Kodi. It is almost like a -Chromecast. :)</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> - - - - - Software created using taxpayers’ money should be Free Software - http://people.skolelinux.org/pere/blog/Software_created_using_taxpayers__money_should_be_Free_Software.html - http://people.skolelinux.org/pere/blog/Software_created_using_taxpayers__money_should_be_Free_Software.html - Thu, 30 Aug 2018 13:50:00 +0200 - <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> - - - - - A bit more on privacy respecting health monitor / fitness tracker - http://people.skolelinux.org/pere/blog/A_bit_more_on_privacy_respecting_health_monitor___fitness_tracker.html - http://people.skolelinux.org/pere/blog/A_bit_more_on_privacy_respecting_health_monitor___fitness_tracker.html - Mon, 13 Aug 2018 09:00:00 +0200 - <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> - - - - - Privacy respecting health monitor / fitness tracker? - http://people.skolelinux.org/pere/blog/Privacy_respecting_health_monitor___fitness_tracker_.html - http://people.skolelinux.org/pere/blog/Privacy_respecting_health_monitor___fitness_tracker_.html - Tue, 7 Aug 2018 16:00:00 +0200 - <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>