X-Git-Url: http://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/bb38026f1c7da4cc23680c02a66d2912d2925a58..eb973c52f2e5a325c7ca6df9b9ff95d4f0dc3100:/blog/index.html diff --git a/blog/index.html b/blog/index.html index 2bdeeec807..caec1056c6 100644 --- a/blog/index.html +++ b/blog/index.html @@ -19,10 +19,325 @@ +
+
Software created using taxpayers’ money should be Free Software
+
30th August 2018
+

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 +Public Money, Public Code to help +them. I hope you too will do the same.

+
+
+ + + Tags: english, opphavsrett. + + +
+
+
+ +
+
A bit more on privacy respecting health monitor / fitness tracker
+
13th August 2018
+

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 +Gadgetbridge. +It provide cloudless collection and storing of data from a variety of +trackers. Its +list +of supported devices 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 +Amazfit +Bip and +Xiaomi +Band 3.

+ +

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 +Garmin +FIT files containing the collected measurements. While +proprietary, FIT files apparently can be read at least by +GPSBabel and the +GpxPod 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 +Garmin Forerunner +935, 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.

+ +

A final idea was to build ones own unit, perhaps by basing it on a +wearable hardware platforms like +the Flora Geo +Watch. 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.

+ +

While I was working on tracking down links, I came across an +inspiring TED talk by Dave Debronkart about +being a +e-patient, and discovered the web site +Participatory +Medicine. 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.

+ +

As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

+
+
+ + + Tags: english. + + +
+
+
+ +
+
Privacy respecting health monitor / fitness tracker?
+
7th August 2018
+

Dear lazyweb,

+ +

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 only 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.

+ +

As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

+
+
+ + + Tags: english. + + +
+
+
+ +
+
Sharing images with friends and family using RSS and EXIF/XMP metadata
+
31st July 2018
+

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.

+ +

Some months ago, I discovered that +XScreensaver 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 +Kodi (both using +OpenELEC and +LibreELEC) provide the +Feedreader +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.

+ +

Armed with motivation and a test photo frame, I set out to generate +a RSS feed for the Kodi instance. I adjusted my Freedombox 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.

+ +

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:

+ +
+exiftool -headline='The RSS image title' \
+  -description='The RSS image description.' \
+  -subject+=for-family photo.jpeg
+
+ +

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.

+ +

Are there better ways to do this? Get in touch if you have better +suggestions.

+ +

As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

+
+
+ + + Tags: debian, english. + + +
+
+
+ +
+
Simple streaming the Linux desktop to Kodi using GStreamer and RTP
+
12th July 2018
+

Last night, I wrote +a +recipe to stream a Linux desktop using VLC to a instance of Kodi. +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.

+ +

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 +the JSON-RPC API in +Kodi 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.

+ +
+#!/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"
+
+ +

I hope you find the approach useful. I know I do.

+ +

As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

+
+
+ + + Tags: debian, english, video. + + +
+
+
+
Streaming the Linux desktop to Kodi using VLC and RTSP
12th July 2018
-

A while back, I was asked by a friend how to stream the desktop to +

PS: See +the +followup post for a even better approach.

+ +

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 @@ -474,246 +789,6 @@ activities, please send Bitcoin donations to my address

-
- -
28th April 2018
-

I VHS-kassettenes -tid var det rett frem å ta vare på et TV-program en ønsket å kunne se -senere, uten å være avhengig av at programmet ble sendt på nytt. -Kanskje ønsket en å se programmet på hytten der det ikke var -TV-signal, eller av andre grunner ha det tilgjengelig for fremtidig -fornøyelse. Dette er blitt vanskeligere med introduksjon av -digital-TV og webstreaming, der opptak til harddisk er utenfor de -flestes kontroll hvis de bruker ufri programvare og bokser kontrollert -av andre. Men for NRK her i Norge, finnes det heldigvis flere fri -programvare-alternativer, som jeg har -skrevet -om -før. -Så lenge kilden for nedlastingen er lovlig lagt ut på nett (hvilket -jeg antar NRK gjør), så er slik lagring til privat bruk også lovlig i -Norge.

- -

Sist jeg så på saken, i 2016, nevnte jeg at -youtube-dl ikke kunne -bake undertekster fra NRK inn i videofilene, og at jeg derfor -foretrakk andre alternativer. Nylig oppdaget jeg at dette har endret -seg. Fordelen med youtube-dl er at den er tilgjengelig direkte fra -Linux-distribusjoner som Debian -og Ubuntu, slik at en slipper å -finne ut selv hvordan en skal få dem til å virke.

- -

For å laste ned et NRK-innslag med undertekster, og få den norske -underteksten pakket inn i videofilen, så kan følgende kommando -brukes:

- -

-youtube-dl --write-sub --sub-format ttml \
-  --convert-subtitles srt --embed-subs \
-  https://tv.nrk.no/serie/ramm-ferdig-gaa/MUHU11000316/27-04-2018
-

- -

URL-eksemplet er dagens toppsak på tv.nrk.no. Resultatet er en -MP4-fil med filmen og undertekster som kan spilles av med VLC. Merk -at VLC ikke viser frem undertekster før du aktiverer dem. For å gjøre -det, høyreklikk med musa i fremviservinduet, velg menyvalget for -undertekst og så norsk språk. Jeg testet også '--write-auto-sub', -men det kommandolinjeargumentet ser ikke ut til å fungere, så jeg -endte opp med settet med argumentlisten over, som jeg fant i en -feilrapport i youtube-dl-prosjektets samling over feilrapporter.

- -

Denne støtten i youtube-dl gjør det svært enkelt å lagre -NRK-innslag, det være seg nyheter, filmer, serier eller dokumentater, -for å ha dem tilgjengelig for fremtidig referanse og bruk, uavhengig -av hvor lenge innslagene ligger tilgjengelig hos NRK. Så får det ikke -hjelpe at NRKs jurister mener at det er -vesensforskjellig -å legge tilgjengelig for nedlasting og for streaming, når det rent -teknisk er samme sak.

- -

Programmet youtube-dl støtter også en rekke andre nettsteder, se -prosjektoversikten for -en -komplett liste.

-
-
- - - Tags: multimedia, nice free software, norsk, video, web. - - -
-
-
- -
- -
24th April 2018
-

VG, -Dagbladet -og -NRK -melder i dag at flertallet i Familie- og kulturkomiteen på Stortinget -har bestemt seg for å introdusere en ny sensurinfrastruktur i Norge. -Fra før har Norge en «frivillig» sensurinfrastruktur basert på -DNS-navn, der de største ISP-ene basert på en liste med DNS-navn -forgifter DNS-svar og omdirigerer til et annet IP-nummer enn det som -ligger i DNS. Nå kommer altså IP-basert omdirigering i tillegg. Når -infrastrukturen er på plass, er sensur av IP-adresser redusert et -spørsmål om hvilke IP-nummer som skal blokkeres. Listen over -IP-adresser vil naturligvis endre seg etter hvert som myndighetene -endrer seg. Det er ingen betryggende tanke.

-
-
- - - Tags: norsk, sikkerhet. - - -
-
-
- -
- -
2nd April 2018
-

Brevpost er beskyttet av straffelovens bestemmelse som gjør det -kriminelt å åpne andres brev. Dette følger av (ny) straffelovs -§ 205 -(Krenkelse av retten til privat kommunikasjon), som sier at «Med -bot eller fengsel inntil 2 år straffes den som uberettiget ... c) -åpner brev eller annen lukket skriftlig meddelelse som er adressert -til en annen, eller på annen måte skaffer seg uberettiget tilgang til -innholdet.» Dette gjelder såvel postbud som alle andre som har -befatning med brevet etter at avsender har befatning med et lukket -brev. Tilsvarende står også tidligere utgaver av den norske -straffeloven.

- -

Når en registrerer seg på usikre digitale postkasseløsningene, som -f.eks. Digipost og e-Boks, og slik tar disse i bruk, så gir en de som -står bak løsningene tillatelse til å åpne sine brev. Dette er -nødvendig for at innholdet i digital post skal kunne vises frem til -mottaker via tjenestens websider. Dermed gjelder ikke straffelovens -paragraf om forbud mot å åpne brev, da tilgangen ikke lenger er -uberettiget. En gir altså fremmede tilgang til å lese sin -korrespondanse. I tillegg vil bruk av slike usikre digitale -postbokser føre til at det blir registrert når du leser brevene, hvor -du befinner deg (vha. tilkoblingens IP-adresse), hvilket utstyr du -bruker og en rekke annen personlig informasjon som ikke er -tilgjengelig når papirpost brukes. Jeg foretrekker at det er -lovmessig beskyttelse av min korrespondanse, som jo inneholder privat -og personlig informasjon. Det bidrar til litt bedre vern av personlig -integritet i dagens norske samfunn.

-
-
- - - Tags: norsk, personvern, surveillance. - - -
-
-
- -
- -
22nd March 2018
-

The leaders of the worlds have started to congratulate the -re-elected Russian head of state, and this causes some criticism. I -am though a little fascinated by a comment from USA senator John McCain, -sited -by The Hill and others: - -

-

"An American president does not lead the Free World by -congratulating dictators on winning sham elections."

-

- -

While I totally agree with the senator here, the way the quote is -phrased make me suspect that he is unaware of the simple fact that USA -have not lead the Free World since at least before its government -kidnapped a -completely innocent Canadian citizen in transit on his way home to -Canada via John F. Kennedy International Airport in September 2002 and -sent him to be tortured in Syria for a year.

- -

USA might be running ahead, but the path they are taking is not the -one taken by any Free World.

-
-
- - - Tags: english. - - -
-
-
- -
- -
21st March 2018
-

So, Cambridge Analytica is getting some well deserved criticism for -(mis)using information it got from Facebook about 50 million people, -mostly in the USA. What I find a bit surprising, is how little -criticism Facebook is getting for handing the information over to -Cambridge Analytica and others in the first place. And what about the -people handing their private and personal information to Facebook? -And last, but not least, what about the government offices who are -handing information about the visitors of their web pages to Facebook? -No-one who looked at the terms of use of Facebook should be surprised -that information about peoples interests, political views, personal -lifes and whereabouts would be sold by Facebook.

- -

What I find to be the real scandal is the fact that Facebook is -selling your personal information, not that one of the buyers used it -in a way Facebook did not approve when exposed. It is well known that -Facebook is selling out their users privacy, but a scandal -nevertheless. Of course the information provided to them by Facebook -would be misused by one of the parties given access to personal -information about the millions of Facebook users. Collected -information will be misused sooner or later. The only way to avoid -such misuse, is to not collect the information in the first place. If -you do not want Facebook to hand out information about yourself for -the use and misuse of its customers, do not give Facebook the -information.

- -

Personally, I would recommend to completely remove your Facebook -account, and take back some control of your personal information. -According -to The Guardian, it is a bit hard to find out how to request -account removal (and not just 'disabling'). You need to -visit -a specific Facebook page and click on 'let us know' on that page -to get to the -real account deletion screen. Perhaps something to consider? I -would not trust the information to really be deleted (who knows, -perhaps NSA, GCHQ and FRA already got a copy), but it might reduce the -exposure a bit.

- -

If you want to learn more about the capabilities of Cambridge -Analytica, I recommend to see the video recording of the one hour talk -Paul-Olivier Dehaye gave to NUUG last april about - -Data collection, psychometric profiling and their impact on -politics.

- -

And if you want to communicate with your friends and loved ones, -use some end-to-end encrypted method like -Signal or -Ring, and stop sharing your private -messages with strangers like Facebook and Google.

-
-
- - - Tags: english, personvern. - - -
-
-
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