So the new president in the United States of America claim to be -surprised to discover that he was wiretapped during the election -before he was elected president. He even claim this must be illegal. -Well, doh, if it is one thing the confirmations from Snowden -documented, it is that the entire population in USA is wiretapped, one -way or another. Of course the president candidates were wiretapped, -alongside the senators, judges and the rest of the people in USA.
- -Next, the Federal Bureau of Investigation ask the Department of -Justice to go public rejecting the claims that Donald Trump was -wiretapped illegally. I fail to see the relevance, given that I am -sure the surveillance industry in USA according to themselves believe -they have all the legal backing they need to conduct mass surveillance -on the entire world.
- -There is even the director of the FBI stating that he never saw an -order requesting wiretapping of Donald Trump. That is not very -surprising, given how the FISA court work, with all its activity being -secret. Perhaps he only heard about it?
- -What I find most sad in this story is how Norwegian journalists -present it. In a news reports the other day in the radio from the -Norwegian National broadcasting Company (NRK), I heard the journalist -claim that 'the FBI denies any wiretapping', while the reality is that -'the FBI denies any illegal wiretapping'. There is a fundamental and -important difference, and it make me sad that the journalists are -unable to grasp it.
+ +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.
+ +I had a look at several approaches, for example +using uPnP +DLNA as described in 2011, 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.
+ +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.
+ +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.
+ +I did not spend much time investigating codeces. I combined the +rtp and rtsp recipes from +the +VLC Streaming HowTo/Command Line Examples, and was able to get +this working on the desktop/streaming end.
+ ++ ++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}' +
I ssh-ed into my Kodi box and created a file like this with the +same IP address:
+ ++ ++echo rtsp://192.168.11.4:8080/test.sdp \ + > /storage/videos/screenstream.m3u +
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. :)
+ +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.
+ +Update 2018-07-12: 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 + +
+ ++cvlc screen:// --sout \ + '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{sdp=rtsp://:8080/}' +
and this on the Kodi end
+ +
+ ++echo rtsp://192.168.11.4:8080/ \ + > /storage/videos/screenstream.m3u +
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.
+ +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: + +
+ ++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. +
and this on the Kodi end
+ +
+ ++echo udp://@239.255.0.1:1234 \ + > /storage/videos/screenstream.m3u +
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. :)!
+ +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.
+ ++ ++cvlc screen:// --sout '#transcode{vcodec=mp4v,acodec=mpga,vb=800,ab=128}:rtp{mux=ts,dst=239.255.0.1,port=1234,sdp=sap}' +
As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
For almost a year now, we have been working on making a Norwegian -Bokmål edition of The Debian -Administrator's Handbook. Now, thanks to the tireless effort of -Ole-Erik, Ingrid and Andreas, the initial translation is complete, and -we are working on the proof reading to ensure consistent language and -use of correct computer science terms. The plan is to make the book -available on paper, as well as in electronic form. For that to -happen, the proof reading must be completed and all the figures need -to be translated. If you want to help out, get in touch.
- -A - -fresh PDF edition in A4 format (the final book will have smaller -pages) of the book created every morning is available for -proofreading. If you find any errors, please -visit -Weblate and correct the error. The -state -of the translation including figures is a useful source for those -provide Norwegian bokmål screen shots and figures.
+ +Five years ago, +I +measured what the most supported MIME type in Debian was, 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: + +
Debian Unstable:
+ ++ 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 ++ +
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"
+ +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:
+ ++ ++% 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 +% +
Using the same method, I can quickly discover that the Sketchup file +format is not yet supported by any package in Debian:
+ ++ ++% appstreamcli what-provides mimetype application/vnd.sketchup.skp +Could not find component providing 'mimetype::application/vnd.sketchup.skp'. +% +
Yesterday I used it to figure out which packages support the STL 3D +format:
+ ++ ++% appstreamcli what-provides mimetype application/sla|grep Package +Package: cura +Package: meshlab +Package: printrun +% +
PS: A new version of Cura was uploaded to Debian yesterday.
+ +As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
A few days ago I ordered a small batch of -the ChaosKey, a small -USB dongle for generating entropy created by Bdale Garbee and Keith -Packard. Yesterday it arrived, and I am very happy to report that it -work great! According to its designers, to get it to work out of the -box, you need the Linux kernel version 4.1 or later. I tested on a -Debian Stretch machine (kernel version 4.9), and there it worked just -fine, increasing the available entropy very quickly. I wrote a small -test oneliner to test. It first print the current entropy level, -drain /dev/random, and then print the entropy level for five seconds. -Here is the situation without the ChaosKey inserted:
+ +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':
+ ++ ++#!/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 +
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.
+ +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).
+ +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.
-- --% cat /proc/sys/kernel/random/entropy_avail; \ - dd bs=1M if=/dev/random of=/dev/null count=1; \ - for n in $(seq 1 5); do \ - cat /proc/sys/kernel/random/entropy_avail; \ - sleep 1; \ - done -300 -0+1 oppføringer inn -0+1 oppføringer ut -28 byte kopiert, 0,000264565 s, 106 kB/s -4 -8 -12 -17 -21 -% -
The entropy level increases by 3-4 every second. In such case any -application requiring random bits (like a HTTPS enabled web server) -will halt and wait for more entrpy. And here is the situation with -the ChaosKey inserted:
- -- --% cat /proc/sys/kernel/random/entropy_avail; \ - dd bs=1M if=/dev/random of=/dev/null count=1; \ - for n in $(seq 1 5); do \ - cat /proc/sys/kernel/random/entropy_avail; \ - sleep 1; \ - done -1079 -0+1 oppføringer inn -0+1 oppføringer ut -104 byte kopiert, 0,000487647 s, 213 kB/s -433 -1028 -1031 -1035 -1038 -% -
Quite the difference. :) I bought a few more than I need, in case -someone want to buy one here in Norway. :)
- -Update: The dongle was presented at Debconf last year. You might -find the talk -recording illuminating. It explains exactly what the source of -randomness is, if you are unable to spot it from the schema drawing -available from the ChaosKey web site linked at the start of this blog -post.
+As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.