intro this part is a continuation of the previous post. In this post i will explain how to stream video with ffmpeg on a LAN, and keep the latency as low as possible. note: this post is for lan only, client and server need to be on the same network or wifi. (In detail: you need te be in the same layer 2 segement) this is because we use multicast udp to transport the video.

FFMPEG is a video and audio manipulation library and cli program. ffmpeg is the main tool ffplay is a simple graphical viewer. ffprobe will only probe input data (file, stream, … ) A short explanation how the ffmpeg cli accepts parameters: ffmpeg <globaloptins> <format> <inputfile_options> <input> <output_option> <output> show info the ffmpeg cli has alot of options, this will give you a good starting point to find info about them:

introduction Since my last endavour in low latency firewalling, a lot has happend in the linux networking world. New algorithms where developed that reduce manual configuration by a large factor. I use this setup at home to: keep gaming latency low keep voice call’s (teams, slack, discord, teamspeak) latency low even in the event that there is high upload (cloud sync, email with large attachment, video streaming, backup), response times for interactive traffic are low and usable.

it is possible to do a live packet capure on a remote linux machine and process it live in wireshark on a windows machine. you need to have wireshark and plink (comes with putty) installed. To get a remote packet capture from a linux computer to a windows machine running wireshark: plink user@host -batch -P 222 "sudo tshark -i eth1 -w - " | "c:\Program Files\Wireshark\Wireshark.exe" -k -i - plink: windows executable that create’s an ssh link user@host: ssh user and host -batch: no questions asked -P: used port sudo tshark -i eth1 -w - : with sudo execute tshark on the remote server, listening on interface eth0 and -w write the output to stdout pipe the output of the remote ssh command to wireshark -i -: use stdin as input for wireshark

my backup server is running btrfs (kernel wiki) with raid1 (mirror), but i’m running out of space and don’t want to upgrade. And raid1 isn’t even necessary, it is the backup after all. To free up some space, well half of it, i used this command: btrfs balance start -dconvert=single / you can live migrate between ‘profiles’, for example from ‘single’ (data is saved only once on the btrfs filesyste), to raid1

ah, na 4 jaar nog eens een post zeg. De website wordt nu niet meer gemaakt met wordpress, maar met hugo. Niet dat wordpress slecht was, maar ik wilde geen mysql en php gebruiken ivm veiligheidslekken. Wordpress staat nu niet echt bekend voor zijn betrouwbaarheid qua beveiliging. In gebruik was wordpress wel goed! Hugo is een “static generator”, wat wil zeggen dat de website niet dynamisch gegenereerd wordt (zoals wordpresss), maar statisch.

Sometimes you raspberry pi (or other boards: arduino, olimex) has no Internet access but you want to keep time between reboots. A rtc (real time clock) will do the job. First, get one! They can be found on popular sites and ebay. The DS3231 is a bit more accurate than the other rtc’s but they all will do the job. adafruit ebay ebay2 olimex when you have an rtc module you have to connect with you raspberry.

At our lan party we use a yagi antenna to connect to fon-hotspots. But they are quite large difficult to mount indoors. And I was curios how antenna’s work. Well, there are a lot of different antenna types, I discovered. I wanted to build on on the following conditions cheap antenna easy to build First idea was to build a cantenna. But a bi-quad looks even more interesting! The corner antenna is the simplest of them all!

Fieuw, after a few hours of searching and testen i’ve got it working! Cacti can now shows disk io of our windows 2008 servers! Here is how i did it: wmi-client libwmiclient1 download them and install at http://www.orvant.com/packages/(go to bottom) cacti wmi plugin, download the wmi.phpand put it in your cacti/scripts/ folder. Make sure the webserver you are running can read the file! http://svn.parkingdenied.com/CactiWMI/trunk/ cacti wmi templates

Searching the web I stumbled upon: cyberciti It motivated me too share my own bashrc, have fun with it. my bashrc