Author: Barry O'Donovan

Testing SPAM and Virus Filters

I’ve recently performed a complete upgrade of Open Solutions’ mail servers and I’ve now moved onto doing likewise for one of our ISP customers with a lot of users.

These retrofits include installing virus and SPAM filters to protect both ourselves and the ISP customers but also to stop customers who have infected computers from spewing these emails out.

When everything’s up and appears to be working, I like to test both filtering systems to ensure they’re working. Quoting from eicar:

Using real viruses for testing in the real world is rather like setting fire to the dustbin in your office to see whether the smoke detector is working. Such a test will give meaningful results, but with unappealing, unacceptable risks.

Fortunately, test files exist for virus checkers and SpamAssassin:

  • The EICAR standard anti-virus test file can be found here.
  • SpamAssassin created the GTUBE (Generic Test for Unsolicited Bulk Email) for the same purpose and this can be found here.

We’re Now Available Over IPv6!

You probably won’t have noticed but this site is now available over IPv6:

$ host www.barryodonovan.com
www.barryodonovan.com has address 87.232.16.35
www.barryodonovan.com has IPv6 address 2a01:268:3002::35

I spend a lot of my working hours doing a lot with IPv6 and, as any sys admin knows, it’s quite often the case that you get around to doing these things for yourself last. In our case, there was a bit of work involved as we had to first get our ISP’s core network dual stacked with IPv6 – luckily they’re a customer of ours 😉

Stay tuned here and over on the company blog for upcoming IPv6 posts and announcements.

In the meantime, if your ISP isn’t offering IPv6 to end users yet, head on over to SixXS where you can get an IPv6 tunnel for free. If you’re based in Ireland be sure to chose HEAnet or Airwire as your PoP as they’re both based in Ireland and members of INEX so your latency will be as low as possible.

UPDATE: Much more on this an why over on the company blog: We’re IPv6 Ready – Finally!

Asterisk SIP Brute Force Attacks on the Rise

See my article on the company blog for a discussion on this, and a how to on using Fail2ban to help stop these attacks.

Go That Way, Really Fast

In the vein of Release Early, Release Often, Jeff Atwood, CTO of StackOverflow.com, has posted an interesting article on the topic and on the huge amount of work they have gotten done in five months and their fears that they’re still not moving fast enough.

We’re going to go that way, really fast. And if something gets in our way, we’ll turn.


Continuous Integration for PHP

I stumbled upon phpUnderControl today by chance and it looks like a very interesting project which integrates:

I hope to take a closer look at it in the near future for a new project we’re lining up at work (want to help us?).

Speaking of continuous integration, for another project we installed and look after a Hudson server for a customer who is developing a Java and Cocoa application – if you’re looking for a CI tool for a Java (or other) development project, this is definitely worth a look (easy installation, nice and intuitive interface and well featured).

Open Solutions is Hiring

We’ve just announced that we are looking for someone new to join our team over at Open Solutions.

UPDATE: Official Announcement

We’ve just announced that we are looking for someone new to join our team over at Open Solutions.

We’ll be making a more official announcement later next week but I’m heading away for a few days and wanted to get something out there.

Encoding Video for the HTC Desire

A useful script to encode all files passed as parameters(s) for viewing on a HTC Desire.

While I’m writing about video encoding, another task I did recently was encode a load of video files for my HTC Desire (a handset I’d strongly recommend for anyone). The main reason being that I like to watch something while pounding the threadmill in the gym.

A useful script to encode all files passed as parameters(s) (must all end in .avi) is:

#! /bin/bash

src="$*"
dst="_${*%%avi}mp4"

echo -en "Encoding $src\t\t\tPASS1"

ffmpeg -b 600kb -i "$src" -v 0 -pass 1 -passlogfile FF -vb 600Kb \
    -r 25 -an -threads 2 -y "$dst" /dev/null

echo -e "\tPASS2"

ffmpeg -b 600kb -i "$src" -v 0 -pass 2 -passlogfile FF -vb 600Kb \
    -r 25 -threads 2 -y -vol 1536 "$dst" /dev/null

rm FF-0.log

Encoding Full HD as FLV (for Gallery3)

I have a full HD camcorder and I wanted to stick some good quality video on my gallery for relatives to view. So, I needed to convert my sample 100MB MP4 full HD file to a suitably sized FLV for the Gallery. Here’s what I did…

I have a very nice Samsung R10 Full HD Camcorder which I bought last year. After a recent family holiday, I wanted to stick some good quality video on my gallery for relatives to view. The gallery is RC2 of the excellent Gallery 3 package which uses another excellent open source tool called Flow Player to play movies.

So, I needed to convert my test 100MB MP4 full HD file to a suitably sized FLV for the Gallery. My initial attempts with ffmpeg worked fine but the quality (sample) was very poor and changing the bit rate in different ways seemed to make no difference:

ffmpeg -i HDV_0056.MP4 -vb 600k -s vga -ar 22050 -y Test.flv
ffmpeg -i HDV_0056.MP4 -b 600k -s vga -ar 22050 -y Test.flv
ffmpeg -i HDV_0056.MP4 -vb 600k -s vga -ar 22050 -y Test.flv

I then turned to x264 and broke the process down to a number of stages:

  1. Extract the raw video to YUV4MPEG (this creates a 7GB file from my 100MB MP4): 
    ffmpeg -i HDV_0056.MP4 HDV_0056.y4m
  2. Encode the video component to H.264/FLV at the specified bit rate with good quality: 
    x264 --pass 1 --preset veryslow --threads 0 --bitrate 4000 \
        -o HDV_0056.flv HDV_0056.y4m
x264 --pass 2 --preset veryslow --threads 0 --bitrate 4000 \
        -o HDV_0056.flv HDV_0056.y4m

    Note that I’m using the veryslow preset which is… very slow! You can use other presets as explained in the x264 man page.

  3. Extract and convert the audio component to MP3 (the sample rate is important): 
    ffmpeg -i HDV_0056.MP4 -vn -ar 22050 HDV_0056.mp3
  4. Merge the converted audio and video back together: 
    ffmpeg -i HDV_0056.flv -i HDV_0056.mp3 -acodec copy \
        -vcodec copy -y FullSizeVideo.flv

    This yields a near perfect encoding at 22MB. It’s still full size though (HD at 1920×1080).

  5. The last step is to then use ffmpeg to resize the video and it now seems to respect bit rate parameters: 
    ffmpeg -i FullSizeVideo.flv -s vga -b 2000k \
        -vb 2000k SmallSizeVideo.flv

The resultant video can be seen here.

Robert Swain has a useful guide for ffmpeg x264 encoding.

Emily @ Glenroe Open Farm

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From their own site:

Glenroe Farm is one of Wicklow’s top tourist attractions. The farm is ideally located beside the picturesque North Wicklow coastline and less than an hour from Dublin City just off the N11.The farm is both educational and fun and here you can get up close to a wide variety of farm animals and pets, enjoy the great outdoors, relax in the peace and tranquillity of our Nature walk, have fun in the large outdoor playground overlooking the farm, try our home cooking from the Coffee Shop or bring your own picnic.