Transcoding for mobiles
There are times where I need a few films on my mobile for my son to watch. For my particular mobile “Galaxy Gio” the constraints for hardware acceleration is 360p as anything bigger will cause it to switch to software which is slower and sometimes a slideshow. For the uninitiated, 360p means either 480×360 at 4:3 ratio (your old TV) or 640×360 at 16:9 ratio (your HD TV).
First we need to cleanup our file names and sometimes ‘rename’ doesn’t work properly. We list all files and separate them by commas and then parse line by line to first remove everything between () and then everything between . We then move from the old name to the new name.
Latency simulation over long fat network
One of our clients asked us how we handle latency, and not just a few ms across racks but 2 and even 3 digit ms latency that indicates geographically separate locations across continents, not just a country. Not only that, the “pipes” involved are 10Gbps and we had to fill them. We have the theories and made models of how it would work. We perhaps might not be able to fill a 10Gbps fully with one stream, we could fill it with multiple streams but we had to validate this conclusion.
The question now becomes, how do we test this. We’ve done our research and there are only a few commercial solutions available like the Netropy 10G2 which is a 4 port, 2 lane hardware latency simulator for $30,000 new. Not only is that outside my budget, it is still limited to simulating 2 10Gbps pipes while we need at least 3 lanes (6 ports) and possibility to expand to more as necessary. We decided it was cheaper in terms of total cost to put the research into creating our own Latency Simulator.
Dell DSET on Ubuntu 10.04 and 12.04
Dell System E-Support Tool (DSET) is an informative tool used by Dell’s support engineers to help diagnose problems for their clients. It is almost a requirement now and Dell usually refuses to continue support without a DSET report.
The problem is that DSET is only supported on Redhat and SuSE Linux and there isn’t any information on how to get it running in Ubuntu. I’ve assembled a rough guide on how to get DSET up and running on Ubuntu 10.04 and 12.04 and it is tested against a Dell R610 and R620.
Kabouter: a gnome terminal based multi-ssh connector
Kabouter is Dutch for gnome and also a tool to connect to a range of IP addresses via ssh. It uses gnome-terminal to manage the sessions which, for me, seems more natural than some of the other 3rd party SSH applications available.
Usage is simple:
[email protected]:~$ kabouter ampli 172.19.18.65 172.19.18.96
This creates a gnome-terminal session with 32 tabs connecting to the range of SSH enabled machines. This works very well when using it with SSH Multiplexing which then gives you a way to automate remote commands through SSH without needing secure key authentication and without having to authenticate each time you want to run a command.
vNES for J2ME on your mobile
If you have ever wanted to play a NES game on your mobile, then you might have heard about vNES. There is a J2ME version which allows it to run on most mobiles available today.
There are however a few rough edges to this application as it requires assembling the necessary files together and running a windows batch file. From a Linux point of view, I have created a replacement shell script that does a better job. It requires unix2dos, rename, and bash.