Amal Pillai

Pre-posterous

2009-12-16T21:16:00.000+05:30

Recently, I came across posterous and found that be a good site to write about something in more than 140 characters. I guess for a lot of what I would like to write, especially random thoughts, observations and fun stuff, posterous looks easier to use - and much faster and simpler to post !

So, I am experimenting with posterous for a while - project "pre-posterous". Here is a link to my posterous site

No access / slow loading / timeout of Linkedin

2009-08-13T20:33:00.003+05:30

I have been experiencing slow response (initially), and more recently, timeout while attempting to connect to Linkedin from home (Dell Inspiron 1420 running Ubuntu Hardy Heron 8.04, Firefox 3.1x or 3.5x, with D-Link 2640T ADSL/Wi-Fi combo modem/router. Apparently, there was no problem connecting with the office VPN, or through a proxy (e.g. www.tntproxy.com), but then Javascript is disabled with a proxy access --> I cannot update the profile or manage contacts.

I finally fixed the problem with the material discussed in:
http://marzoa.com/2009/03/08/d-link-dsl-g624t-and-linkedincom
https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/314713.

The ADSL default configuration for PPPoE is MTU (Maximum Transmission Unit) at 1400 and MRU (Maximum Receive Unit) at 1492. (I have Airtel 512 kbps DSL connection) Changing this to match the eth0 MTU default value of 1500 on the DSL modem did no good - apparently the modem cannot handle MTU = 1500. So, I tried the two steps to remove the iptables FORWARD and change the eth0 MTU:

(a) Delete the iptables rule as described from the router. I too had the offending line in position 1
iptables -D FORWARD 1
(b) Reset MTU on the machine (interface eth0 in my case)
sudo ifconfig eth0 MTU 1400
The MTU value is 1400 since TCPMSS is set to 1360 in the router. (Note: TCPMSS = 1400 - 40 = 1360)

Naturally, it is not a stable fix: I have to telnet to my modem, reset the iptables each time, but something is better than nothing... Next step: Try to upgrade router firmware and pray it does not screw things up any further ;-)

More fun with ffmpeg...

2009-08-01T19:36:00.006+05:30

The standard ffmpeg installed with Ubuntu does not have libmp3lame for mp3 encoding. Paul Maunders describes how to install ffmpeg with libmp3lame support from the Medibuntu distribution. Now it is easy to rip mp3 off a flash video file in either of the following ways:


ffmpeg -i some.flv -acodec mp3 some.mp3
ffmpeg -i some.flv -vn -acodec copy some.mp3

Here is the output from my machine:


apillai@giraffe:~/Videos/$ ffmpeg -i some.flv -vn -acodec copy some.mp3
FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2007 Fabrice Bellard, et al.
  configuration: --enable-gpl --enable-pp --enable-swscaler --enable-pthreads --enable-libvorbis --enable-libtheora --enable-libogg --enable-libgsm --enable-dc1394 --disable-debug --enable-libmp3lame --enable-libfaadbin --enable-libfaad --enable-libfaac --enable-xvid --enable-x264 --enable-liba52 --enable-amr_nb --enable-amr_wb --enable-shared --prefix=/usr
  libavutil version: 1d.49.3.0
  libavcodec version: 1d.51.38.0
  libavformat version: 1d.51.10.0
  built on Mar 17 2009 21:37:49, gcc: 4.2.4 (Ubuntu 4.2.4-1ubuntu3)
Seems stream 0 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 29.97 (30000/1001)
Input #0, flv, from 'some.flv':
  Duration: 00:04:43.9, start: 0.000000, bitrate: 64 kb/s
  Stream #0.0: Video: flv, yuv420p, 320x240, 29.97 fps(r)
  Stream #0.1: Audio: mp3, 22050 Hz, mono, 64 kb/s
Output #0, mp2, to 'some.mp3':
  Stream #0.0: Audio: mp3, 22050 Hz, mono, 64 kb/s    <=== mp3 stream
Stream mapping:
  Stream #0.1 -> #0.0
Press [q] to stop encoding
size=    2219kB time=284.0 bitrate=  64.0kbits/s  
video:0kB audio:2219kB global headers:0kB muxing overhead 0.000000%
apillai@giraffe:~/Videos/$

Now we have a clean mp3 that can be played on your ipod! Tux Radar has a nice write up on ffmpeg tips and tricks.

Holy crap !

2009-06-17T19:56:00.007+05:30

Here is an extract from a recent post by Uncle Bob in the ObjectMentor Blog:

"CRAP is a metric that is applied to each function in the system. The formula for CRAP is: CRAP = comp(f)2. X (1 – cov(f)/100)3. + comp(f), Where comp(f) = the cyclomatic complexity of the function f. and cov(f) = the unit test coverage of function f. So a function’s CRAP will be small iff the cyclomatic complexity is low and the test coverage is high. CRAP will be huge if cyclomatic complexity is high, and there is no coverage."

They even have a tool available for measuring this: crap4j ! Take a look at that sample report ! Holy crap ! What a change from the dry formality of percentage of dead code, fault density and so on... A follow-up post is here.

The twp (thin wallet program)

2009-06-14T16:31:00.002+05:30

I started an active intent to reduce the size of my wallet around the New Year. My wallet was becoming a dumpyard of transaction slips, cash, coins a few credit / debit cards, assorted visiting cards and what not... After all, size zero is so much in vogue these days and I didn't see why I should not cut the wallet to size first.

So I sat down and looked at what is really essential and came to the following conclusion: At any point of time, a couple of cards, copy of my driving license and some petty cash is fine. Coins are useless - not even beggars accept them these days. Transaction slips can be shunted out every other week; visiting cards can be kept elsewhere.

I purchased a new thin wallet that can hardly accommodate these items (lest I fall prey to stuffing once again) and I have been happy since the last few months. Optimization at times is not so much of an evil...

Movie List

2009-05-24T08:18:00.005+05:30

I have listed down a few interesting movies I have seen over the last few years. None of them are of the popular genre, nor are they too artistic to leave you with a sinking feeling of "what the hell was that" after the movie is over. UTV world movies has been airing a few of them - for the others you have to search other sources (Youtube ?). More of them, in a later post.

A man without a past, Drifting clouds (Finland): Amazing movies from the Finnish director Aki Kaurismäki
Darkness in Tallinn (Estonia) : Powerful play of darkness and light to depict the greed of the powerful and life of the ordinary
Dead man (English) : Haunting... that is all I can say about the movie and the music by Jim Jarmusch. Johnny Depp at his best ?
Junoon : A 1978 movie of Shyam Benegal, based on Flight of the Pigeons by Ruskin Bond.
The Valet" (France), Swindled (Spain) : Light comedies interspersed with realism.
My Girl (Thai) : You cannot but laugh nostalgically about childhood.
Children of Heaven, The Circle (Iran): So realistic, so poetic, so powerful...
Massacre in Rome (English) : Another war movie at the surface, but there is an eerie similarity with the functioning of a modern day corporate, especially in the politics and decision making around the preparation of execution list...

Free MBTI Online Analysis

2009-01-14T12:35:00.004+05:30

There is a comprehensive, yet free online test for Myers-Brigg Type Indicator. For the curious ones, I tend to be somewhere in between an INTJ and INTP.

Samsung SCX 4300 on Ubuntu

2009-01-14T12:26:00.002+05:30

I bought a Samsung SCX 4300 multifunction device a couple of weeks back. Getting it work with Ubuntu was a little tricky, but thanks to information from Volatile Yard, I got it working completely in a couple of hours. The experiences are listed in Ubuntu Launchpad and in Ubuntu Forums

Dell Inspiron 1420

2008-08-03T21:37:00.003+05:30

I got a new Dell Inspiron 1420 for my personal use and installed Ubuntu to dual boot it with the pre-installed Windows Vista. Installing a Linux distro for dual booting has come a long way since the first time I did it with Slackware and Windows NT - one needed to know the disk geometry, ensure that the partitions were within the first 1GB, tweaking the MBR and and worst, finally hand-tuning the X-Windows setup for a clean resolution. With Ubuntu, it looked like a "fire and forget". Good !

Getting the WiFi connection to work with the DELL 1395 mini-card (Broadcom 4315) needed a little tweak as outlined in http://ubuntuforums.org/showthread.php?t=704088, but it worked perfectly. What surprised me was that the Broadcom 4315 drivers that shipped with laptop for Vista did not work with ndiswrappers.

So far, so good.

The future of telco platforms

2008-06-05T20:19:00.003+05:30

A couple of months back, I saw a video on JavaFX by James Gosling that set me thinking.
Application development has already shifted to favor scripting languages and a general purpose platform such as Java. Adobe, Microsoft, Sun and Google are targetting the mass applications market with their emerging technologies (Silverlight, Flash, Ajax...) At present, industry strength platforms are developed by individual organizations for specific domains such as telecom, medical imaging and automation segments, which traditionally have been considered specialized with real-time requirements. JavaFX promises much more and possibly make a big headway into these niche areas dominated by systems and real-time programming. Let us look at a few interesting things that are happening around us:

Commoditization of multi-core machines is making parallelism as an essential, low level feature.
The OS is evolving into something more than what it is today, it is providing runtimes for multiple languages and various persistence models.
Parallelism and persistence are becoming part of languages. Rather higher order and domain specific languages such as F#, Erlang, Scala are increasingly becoming viable alternatives for industry wide usage.
Compiled languages like C and C++ are either moving to niches or are on their way out.

Sun has recently acquired MySQL AB and now hired Python programmers to allow JVM to run Python natively. Ah, may be Jython would now be part of Java ! Let us look at activities of Microsoft and Sun Microsystems in pushing their platforms.

Common runtime: .NET/CLR from MS, (j)VM from Sun.
Languages: MS supports C#, managed C++, Python, Ruby (and a host of languages) while Sun is focussed on Java and Python
Persistence : MS supports LINQ while Java has many persistence models right from POJO to beans to frameworks such as Hibernate.
Higher order languages: MS is pushing F# while Scala is emerging as a serious contender in the Java world.
Dev tools/IDE : Visual Studio vs. NetBeans

Evidently, MS and Sun are pursuing similar tactics. Here are my predictions:

In five years time, systems programming as a act of fighting with pointers, malloc/new, dumping core files, threads and writing obscure code for performance would reduce drastically.
Increased acceptance of domain-specific and higher order languages will bring code closer to models. This will make design and modeling an important domain specific activity.
The specific "platforms" for embedded systems, telecom, media processing, medical imaging will coalesce into a single basis, with protocol / interface extensions and DSLs for the specific nature of work.

The average programmer "writing code" for these domains will be relegated to level of a skilled blue-collar worker. This is already happening in application space - see the amount of outsourcing for coders. The scientist and the domain specialist can and continue to design systems. Of course, the specialist and highly skilled programmer would always be around to build and maintain the platforms.

Linux schedulers

2008-06-04T21:29:00.000+05:30

Some interesting links on the evolution of linux schedulers which discuss scheduling functions, O(1) scheduling and view-points on pluggable schedulers:

The O(1) scheduler: Available in 2.6 kernel series
CFS from Ingo Molnar: Available from Linux kernel 2.6.23+
RSDL from Con Kolivas: Sadly, Con quit kernel development unable to resolve the differences between himself, Ingo and Linus.

People, Management and Programming

2008-06-04T19:44:00.002+05:30

I found a few links that look at the management to software development in an unconventional way:

Peopleware is excellent example of how an ideal world would be for engineers.

Want to learn programming ?

2008-06-03T19:30:00.003+05:30

I often get to talk to beginners asking me at workplace on how to go about improving their programming skills. I learnt programming with free software (Linux, gcc) and hence my advice is naturally biased towards them.

The first step is to familiarize oneself with a few basic things:

An OS: Linux is my pick, though Win32 is not a bad choice. I find Ubuntu is an excellent distro that comes packed with all the goodies and a nice package manager to work with.
A compiled language : I suggest C++ or Java. It is unfair to be biased towards either. Rule of thumb: If you are interested in applications and "higher level" aspects - pick Java. On the other hand, if you want to write high-performance servers and systems, pick C++. And if you like to get into kernels and drivers, pick C. gcc is a great thing for C/C++
An interpreted language : My pick is Python for its elegance and simplicity.

Once you fix this up, pick the right tools. The most important of them are:

A good programmer's editor: For C/C++, it is better to start with a modern clone of vi or Emacs unless you are GUI freak. Java learners would be better off sticking to Eclipse or NetBeans. Whatever it is, ensure that it is a good programmer's editor - supports easy editing, commenting, indentation, compilation and integrates the debugging to some extent.
Environment: Nothing to beat the Unix tools. If you are on Win32, consider installing Cygwin or MinGW.
Build: I recommend CMake for C/C++ programmers. It saves a lot of time wasted in writing makefiles by hand and you also get a chance to organize a project. Java programmers would use Ant anyway.

You should aim for being able to write a small program in your editor, compile it and run / debug it with a debugger. It can be as simple as a "hello world", but you should be able to do it.

Other supporting things you should learn in due course :

Version control : Subversion is a good choice.
Packaging : How to package your sources and binaries: e.g. RPM
Programming style : How to make good designs, write good code and maintain the style. Keep doing it !

Finally, do not forget that technology is not exclusive to relationships, sociological aspects, management and politics. Learn as you go !

Landings per bridge - II !

2007-11-01T19:13:00.000+05:30

Addendum to the earlier post Landings per bridge

It appears that airplanes take off towards the M-Bridge during the season of the North-East monsoon and landings are from the other side. I now avoid the bridge at insane rush hours.

Video encoding with OSS tools

2007-11-01T18:29:00.001+05:30

I did a few quick and dirty experiments to convert the AVI video files shot with my Canon S2 IS to mpeg and Theora/Ogg formats. Looking for open source options, here are the details I found:

MPlayer: A neat cross platform player(mplayer) and encoder(mencoder).
ffmpeg: Another neat encoder (ffmpeg) and player (ffplayer). ffmpeg2theora is a quick and dirty option for conversion to Theora/Ogg formats.

Pre-built binaries are available for both programs for Windows and Linux. ffmpeg was the easiest to use. It converted my files (video: 30fps, 790kbps, 320x240 pixels, audio: 16bit PCM @ 1411kbps) to 1/3 size for mpeg at near lossless quality (-sameq). Here is a bash script that will do this for all AVI files in a given directory:


for i in `ls *.AVI`
do ffmpeg.exe -sameq -i $i ${i/\.AVI/\.mpg}
done

The Theora/Ogg converter does an excellent, but lossy compression (1/10 file size).


# automatically writes to Theora/Ogg format
ffmpeg2theora-0.19.exe file.avi

The video and audio lossage can be controlled by specifying -v and -a, but the Theora/Ogg file size approximated the mpeg file size for a slightly deteriorated quality of video with -v8. I have not tried out mencoder that ships along with MPlayer.

A couple of observations:

Noise in the video is noticeable only when the video is played at full-screen mode.
I would rate MPlayer better that ffplay (better full-screen support). Another popular cross platform player is VLC
MPlayer, ffmpeg and IceCast provide options to build video streaming servers. Programmers should look at the nice tutorial on how to write a video player with SDL and ffmpeg API.

Landings per bridge !

2007-08-19T12:09:00.000+05:30

While idling at the infamous M bridge during the rush hour traffic in Bangalore, I figured out a new way to measure traffic. Forget Little's theorem , Erlangs and passenger car units (pcu) per hour : here is a new and simple unit called landings per bridge.

The number of aircraft landings in the Bangalore HAL airport during the morning rush hour is fairly constant: approximately once every four minutes. Depending on the traffic, the more landings I witness while stuck on the bridge (which is one of the worst points of congestion), the higher is the degree of congestion ! An average morning is rated between 4-5, a bad day can run upto 8.

PS: I have to resort to the pcu/hr once the airport shifts to Devanahalli !

R&D, Patents, Innovation - the current game

2007-03-20T13:35:00.001+05:30

I happened to see a few articles / comments in the last few days on patenting and R&D. There is enough noise on the concept of patenting (especially on software patents). Have a look at this:

Linked list patented in 2006 : I didn't know linked lists were invented after they were taught in school.
Demise of the corporate R&D : The gestalt is probably the statement "many of the big scientific questions in computing have been answered—at least well enough for companies to find that innovation emerges from new ways of arranging today's technologies rather than inventing new ones". Perhaps this is why we have patents like the one above.
Organizations asked to donate patents : Should organizations be allowed to lock away interesting finds (in the form of patents, IPR) because they cannot/do not want to commercialize it ? To me, it looks more like the treatment of telecom spectrum - it is auctioned away to people who can run a telecom business rather than for allow squatters to sit on it. Here is a beautiful article on the bidding game.

Across the Great Wall

2006-09-23T23:44:00.000+05:30

I was in Beijing in the last week of July on an official visit - it was my first visit to China. The weather was temperate with occasional sun and lot of rain and grey clouds - probably due to the typhoons brewing in the eastern sea.

Snapshots from the trip :

Beijing was impressive - infrastructure, automobiles, business and of course driving sense ;-) The China daily had real news including coverage of the western world, but it had little political discussion or opinion. One page was dedicated to new ventures in hi-tech and manufacturing industries - the variety was awesome ! Traffic jams are bad, but the drivers do follow rules.
Shopping in the Sunny market (near Holiday Inn, Lido Place) which sells all and sundry items such as souvenirs, clothes, suitcases is an experience. Everything is cheap and most "branded" stuff is a "fake original". Bargaining seems to be the rule - you start from, say 200RMB for a suitcase (first quote) and can over a period of 5-10 minutes reduce the price to 50RMB (one RMB is ~ INR 5.7 if you buy it, selling rate is bad at INR 4.6 - 4.8). The sellers were mostly girls who speak excellent english. I admire their resilience and optimism. I bought some specialties : A "SAMSONITE" laptop bag at ~ INR 350, a nice painting, some ceramic and traditional chinese clothes (reminiscent of the sartorial outfit of little Pu Yi in the "Last emperor") for my daughter.

Food is excellent unless you are finicky about eating meat. The popular hyperbole of a menu of cooked insects as snack may be safely discounted. Being a native of God's own country, I relished the prawns, oysters, pork and chicken - all deliciously cooked and served tastefully. Using chopsticks was troublesome and I bravely admitted my ignorance, preferring the western cutlery. The food is nice and lightly spiced except for the Sichuan variety which reeks of chilli sauce! A restaurant (to which my colleagues took us) had a nice performance of the Peking opera, traditional chinese dances and kungfu.

Next time, I would sure like to see more of China, especially the Forbidden City and the Great Wall at Badaling. On the way back, I made use of the stopover at Singapore for a short tour of the city and the weather was fantastic. And then it was back home to the routine

Death of a thespian and life after that

2006-04-23T19:35:00.000+05:30

It started in the most innocuous way I ever imagined.

On Monday, 10th April at 18:00hrs, I was at the airport to my wife and our 3month old baby from the Bangalore airport. Being anxious to meet them, I was eagerly looking at all small babies & their mothers and trying to spot my wife. In the crowd, I noticed a familiar looking young man with a baby girl fast asleep on his shoulder, smiling broadly and walking towards the exit. "Looks like one of Dr. Rajkumar's sons", I mused for a moment... Sure enough, he was escorting his old father & mother, who were all smiles. By now I recognized the actor himself - in spite of his beaming smile, the tiredness and odema on his face and the hobbling walk gave away his health. As he passed by me, I noticed my wife and baby trying to retrieve their luggage and my attention shifted to them. I casually mentioned to my wife " I just saw the Kannada actor Dr. Rajkumar and his health looks really bad..." We spent the evening and the next day busy settling down and stacking up baby food.

While at work on April 12th, I heard rumours on Dr. Rajkumar's ill health and impending disturbances in and around the city, and it was not until 16:00hrs did I get a confirmation from the newsfeeds. After an hour long wait at the gas station, I started driving towards Whitefield at about 17:30 and met thin traffic. The roads were ominously deserted and all shops (even the ones on pushcarts) were closed. Many vehicles had hastily taken printouts of Dr. Rajkumar's photos hoping that to save them from being pelted with stones. Though I encountered blocked roads and burning tyres at Whitefield, I managed to reach home without facing any mishap.

What happened in the next couple of days is well reported by the media. Normalcy returned by Saturday and on Monday, I was back at work after the long weekend. We can debate whether the violence and mayhem was orchestrated or not, but any sensible individual cannot discount the divide between the modern, affluent Bangalorean and the less fortunate who eke out a living doing 3D (dirty, difficult and dangerous) jobs. Time for the intelligentsia and policy makers to take note.

The memory of violence and mayhem are almost erased from public memory by now. (Do you remember the name of the unfortunate young policeman lynched by a mob ? He was only 25 years old... ). But what I remember strongly is the picture of the poor man (in whose name all the vandalism was enacted), hobbling down with his family out of the airport, everyone all smiles, acknowledging the few who wished him, into the sunset. Never did I imagine he was walking out of the airport for the last time and the mayhem his death would bring is so sudden and violent.