About Menelaos Bakopoulos

Mr. Menelaos Bakopoulos is currently pursuing his PhD both at Center for TeleInFrastruktur (CTiF) at Aalborg University (AAU) in Denmark and Athens Information Technology (AIT) in Athens, Greece. He received a Master in Information Technology and Telecommunications Systems from Athens Information Technology and a B.Sc. in Computer Science & Management Information Systems from the American College of Thessaloniki. Since April 2008 he has been a member of the Multimedia, Knowledge, and Web Technologies Group.

Posts by Menelaos Bakopoulos:

XDebug in XAMPP and Netbeans

Having written a lot of PHP code for a project using Notepad++, I got tired with the limitations of not having an IDE containing a debugger, and refactoring tools.

Quick post mostly for myself to have a reference on how to setup XDEBUG (which was quite easy using XAMPP).
If you don’t want to go the long road download the full version of XAMPP here ūüôā

1) First off as the DLL is already located it does not need to be downloaded.
2) Open php.ini and make the following edits:

A) Uncomment the line¬†zend_extension = “Somethingphp_xdebug.dll”
B) Uncomment the variables and set them as specified by netbeans …

2012 in review

The WordPress.com stats helper monkeys prepared a 2012 annual report for this blog.

Here’s an excerpt:

600 people reached the top of Mt. Everest in 2012. This blog got about 3,800 views in 2012. If every person who reached the top of Mt. Everest viewed this blog, it would have taken 6 years to get that many views.

Click here to see the complete report.

Running Java on Fujitsu Q700 NAS Server

NAS+JavaSmall post how I got java to work on Q700 NAS Server.
If you check the Datasheet for the server ( here ), you will see the Processor is a  Marvell 6281 1.2 GHz  . Essentially, this is a ARM 5 processor.
Based on some instructions from here , I navigated to http://www.oracle.com/technetwork/java/javase/downloads/embedded-jsp-135769.html ,
and downloaded the version ARMv5 Linux ‚Äď Headless EABI, SoftFP, Little Endian2 .

All that remained was untar-ing the content onto the NAS, and executing  java Рversion.

How to move “Virtualbox VMs” files

I came across a situation where my VMs were taking too much space from my C drive. The instructions below are from the forum post here.

“The most common I found is to remove your VMs from the manager without deleting the files. “Remove the VMs from the manager without deleting the files. You can then move the entire VM folder (not just the bare VDIs) to a new location, before adding them back to the manager.”

Here’s how I did it… Use these instructions at your own risks¬†;-)


Easily validating your Varnish cache VCL file and other quick tips

I’ve been playing around with varnish lately and had to make a change in a VLC file to perform URL re-writing before following with “hashing”, lookup, and if necessary forwarding to tomcat.
For anyone wanting further information on the varnish pipeline, as well as why someone should use varnish I recommend the following two articles:

1) http://open.blogs.nytimes.com/2010/09/15/using-varnish-so-news-doesnt-break-your-server/?smid=tw-share
2) https://www.varnish-software.com/static/book/VCL_Basics.html


Dealing with FFMPEG Error while opening codec for output stream…

Quick post about the ffmpeg error message: “Error while opening codec for output stream #0.0 – maybe incorrect parameters such as bit_rate, rate, width or height” .

We received some video files from a partner in the Safecity project, which did not play in all media players.
We tried VLC, windows media player, and a variety of other players but nothing worked.

Checking the file with a hex editor, I saw there was data within the video, and thought to try converting with FFMPEG using commands such as:

ffmpeg -i “damaged_file.avi” converted_file.mp4

However, ffmpeg  failed with the following error message:

Error while opening codec for output stream #0.0 – maybe incorrect parameters such as bit_rate, rate, width or height


Logging in VLC 2.0.3 not working in Windows 7 and Fix

Working on a project, I noticed that I could not access the VLC 2.0.3 log (or even see it).

I had followed the instructions related to the Tools>Messages dialog, and changed the Verbosity level to enable the logging but it was not working.

After some thought I realized that as these configurations are stored as files within the VLC program files folder.

VLC must be run as administrator for the logging to actually work due to the windows 7 security restrictions.

Google hiding search parameters in referer address


While checking my statscounter/analytics today and noticed that the number of links starting with the following had increased:

What I don’t like with these links is that I can no longer know what search was used to land the users on my page, in order to be able to tweek my SEO, and know what content is more demanded.

Reading a bit more about this I found out its’ google’s new policy to hide the search parameters for users privacy – Ok I can understand that.

There is however the opinion that this data is for sale if your an advertiser who is paying them (I have not confirmed this).

More information on this from designer Tim Minor in his blog post: Deconstructing Google url search parameters .

Remove duplicate entries from mysql table

Was writing some code, and dealt with this problem…so posting about solving this problem with 1 command (or more) depending on your decision.If you want to remove all duplicate rows with the same combination of N number of columns.

I’ll talk about two options in this post:

Add a unique key constraint that drops all duplicates

This one will remove all duplicates (based on the combination of columns you give) with one line.
The approach works by altering the table, and adding a unique key. Applying this unique key, causes all duplicate rows to be dropped leaving only one.


Quick and dirty PDF translation using Dropbox, and Google Translate

Hey all, quick non-programming post here about how to quickly translate a PDF doc with formatting from google translate (and keep most of the formatting).

Specifically, I wanted to translate a manual for a professional oven to Greek. My example though will use a preliminary version of my MSc thesis:


Google translate supports uploading documents via the translate a document link, but the result is not always very good with formatting.