soledad penadés

London-New York (and back), via Hong Kong, Macau, Tokyo and San Francisco

sole — Sun, 29 Jan 2012 23:03:40 +0000

The sketch book I mentioned a couple weeks ago has finally been released! To recap (just in case you accidentally ended here and have no context), it is a travel sketchbook depicting our experiences while travelling around the world these past April and May.

I’ve finally settled on building a simple HTML(5) page with a sprinkle of Javascript to navigate the bigger images. Something that gets the job done, which is showing you my crazy sketches!

I might possibly build a Kindle version in the near future, so if you’re a Kindle user, stay tuned ;-)

In the meantime you can read a bit about the background and the “tools” in the project page.

A hack to parse RSS feeds with php

sole — Sat, 21 Jan 2012 17:19:37 +0000

Just happened to assemble this ~~script~~ hack recently, out of the requirement for a quick’n'dirty feed parsing feature:

$feed_contents = file_get_contents($feed_url);

$xml = simplexml_load_string($feed_contents, LIBXML_NOCDATA); 

$feed_array = json_decode(json_encode($xml));

print_r($feed_array); // Surprise!!

Now this evidently is not SimplePie or Magpie RSS or whatever feed reader library tickles your fancy*, but assuming the feed will never be malformed, it can save you lots of time! Isn’t that what php was meant for? :-P

At first it surprised me that it would even work–but it seems that the JSON module interoperates very nicely with SimpleXML objects. At the end you get an associative array in $feed_array which is a nice representation of the RSS 2 feed. It’s important to highlight the LIBXML_NOCDATA parameter, as it makes sure the CDATA nodes are read as text. Otherwise you would just get empty feed items, etc.

Obviously for this to work you need both the JSON and SimpleXML modules installed and enabled in your server. Since that’s something that always worries me, I wrote another quick script to test whether the hack would work on the server:

$functions = array('simplexml_load_string', 'json_decode');

foreach($functions as $f) {

  echo $f . ' exists? ' . (function_exists($f) ? 'yes' : 'no') . '
';

}

It should output something like…

simplexml_load_string yes

json_decode yes

Happy hacking! :-P

ffmpeg on Mac Os X Lion

sole — Wed, 18 Jan 2012 22:28:03 +0000

Now that I’m using a Mac (with Mac OS) at work I’m sorely missing truly essential tools such as ffmpeg. The only binary build I could find (without having to download fink and a ton more packages that I don’t really need) was a build from 2006. Two thousand and six! Which in ffmpeg terms is like the Pleistocene.

So given that I have XCode installed anyway, I decided to build ffmpeg myself, just as I had done back in 2007. It should be as doable as back then!

I found a post by Martin Los, which was pretty much all I needed to get started. I just changed a few things; for example you don’t need to -enable-libfaad anymore with recent versions of ffmpeg as I think they have their own (experimental?) faad encoder, and don’t rely on an external library. I also didn’t install SDL as from what I remember it was only used for showing ffplay’s output (mostly for opening a window, showing the decoded video, etc). In any case, ffmpeg compiled fine without having SDL, so I’m assuming it just didn’t compile ffplay which frankly I don’t use.

After I checked that Martin’s method worked, I decided to convert his instructions into an script. Usually I would write this script with Python but I am trying to learn a bit more bash lately, so I made an effort (and several searches) and wrote it in bash –and a couple of other utilities such as sed which were already installed on Mac. I believe the only tool which isn’t installed by default is Subversion, but I am not entirely sure about this (and I’m not going to format the system just to check!).

It was also interesting to use cURL (which is installed on a bare Mac Os) instead of wget, which I expected to be installed already (it wasn’t). Apparently SourceForge (which is where the libraries’ sources are hosted) makes some sort of redirection even if you’re using a direct link. The -L option allows it to follow through 30x redirections until it finds a 200 code or similar.

And here is the script for your enjoyment and all that:

#!/bin/bash



# Thanks to Martin Los for his guide: http://www.martinlos.com/?p=41



URLS=("http://downloads.sourceforge.net/project/lame/lame/3.99/lame-3.99.3.tar.gz" "http://downloads.sourceforge.net/project/faac/faac-src/faac-1.28/faac-1.28.tar.gz" "http://downloads.sourceforge.net/project/faac/faad2-src/faad2-2.7/faad2-2.7.tar.gz")



for i in "${URLS[@]}"

do

        echo $i

        curl -O -L $i

done



for i in $( ls *.tar.gz ); do

        tar -xzvf $i

done



for i in $( ls -d */); do

        cd $i

        ./configure

        make

        sudo make install

        cd ..

done



svn checkout svn://svn.ffmpeg.org/ffmpeg/trunk ffmpeg

cd ffmpeg

./configure --enable-libmp3lame --enable-libfaac --enable-gpl --enable-nonfree --enable-shared --disable-mmx --arch=x86_64 --cpu=core2

make

sudo make install

Using this shiny fresh build of ffmpeg I was able to convert several .MOV files which were rendered for iOS devices into MP4 files that Android devices could palate. This is the script I wrote (also with bash, to practise even more):

WIDTH="720"

HEIGHT="480"

BITRATE="1500k"

for i in $(ls *.mov); do

        ffmpeg -i $i -r 30 -vcodec mpeg4 -acodec libfaac -ac 1 -ar 44100 -vf scale=$WIDTH:$HEIGHT -b $BITRATE  -y $i.mp4

done

for i in *.mov.mp4; do j=`echo $i | sed 's/.mov.mp4/.mp4/'`; mv "$i" "$j"; done

Hope it’s useful!

Friday the 13th / Saturday the 14th

sole — Sat, 14 Jan 2012 13:18:24 +0000

Call me whatever you want to call me, but whenever I hear “Friday the 13th”, I immediately think of the image above.

It was on the front cover of a computer magazine back in 1990 (download it here). Computer viruses (virii?) had just become immensely popular in Spain thanks to the fact that

the Morris worm was still quite recent, and
several huge organisations in Spain had become infected

… triggering a massive, hysterical coverage in newspapers and TV (a moderate example, and more results from the archive).

The most popular virus in Spain was “Friday the 13th”, nicknamed Viernes 13 in Spanish (hence the image header). I always found incredibly funny that one of the removal tools was called “Sábado 14″ (“Saturday the 14th”).

That collaged computer corpse became my computing nightmare. It was a terrifying symbol: what we could end up looking like if we allowed those malicious (and mysterious) virus take over the world.

In my naivety, it scared me in more than one way. For some months I tended to attribute every strange computer behaviour to virus, even if we were simply using an Amstrad PCW, without modem or anything remotely similar, didn’t know anyone else with a machine like this one and thus did never, ever, pirate software. All the software we used was either expensively original back then, or typed from magazine listings, so we had a very low chance of a virus getting into that machine. Taking aside the fact that it didn’t have a hard drive, of course.

That didn’t matter: I suspected that the computer might have got infected somehow. Locoscript making strange things? It might have been a virus. The last line of the screen filled with strange garbage? (it tended to randomly display “~” characters when you pressed a key while the printer was working). It surely was a virus, and the ~ messages were its output. The keys didn’t work properly? (because they were mechanically jammed). A virus, no doubt!

We even discussed virus at school. I mean, just imagine 80′s kids, nine or ten years old, discussing virus on the morning break. Speculating whether this or that thing that happened when you turned on the video recorder could possibly be a virus. Mental!

I didn’t see “a real virus” until we got a PC, and I started to exchange software with more kids in the computers classroom. Even though, those were quite mild infections. Maybe I wasn’t a very dedicated pirate? I remember only four or three viruses we got: Brain, Stoned and that one featuring a bouncing ball.

I recall using a couple of command line tools to get rid of the virus. You first had to run SCAN.EXE and then there was another tool (CLEAN.EXE?) for removing the virus. That was the first “proper” antivirus I used (it seems those were the early beginnings of the McAfee antivirus family). Prior to that, the solutions consisted in running an specific tool for each virus you wanted to remove, or some funny ideas such as making sure the computer was turned off on the day the virus would turn on its payload, or formatting hard drives at low level. That could take ages, and those disks had just 20 megabytes!

Still, those virus were moderately curious in a way, like little pesky creatures that had just arrived into your computer by chance. Annoying, yes, but an unexpected, surprising phenomenon nevertheless. The arrival of the Internet changed things for bad in this field, boooo!

The end of the world

sole — Thu, 12 Jan 2012 22:10:56 +0000

It’s a New Year–we’re actually twelve days off it and I still haven’t found time to sit down and write about it. Which is good!

It’s also many years since I last wrote a “beginning of a year” post. It was different back then–blogs were the rage; journalists were scared of amateur bloggers stealing their jobs and wrote meta-articles describing a pale future in which everything would be clumsily assembled together by said novices. And, well, us the newbies didn’t care, and posted about everything in our blogs anyway. Then the “web 2.0″ came in full swing, and we diluted our content in a myriad of other websites, some of which have disappeared or radically changed their behaviour/rules since then. I’m not too happy with that, and so I declare that one of my main resolutions for this year is to post here more often.

That doesn’t mean that I won’t be posting stuff to other websites such as plus or twitter, as I’ve noticed that many people use them as a mixture of human RSS aggregators and comments section.

Onwards to this year’s projects/resolutions: since this is the year the world ends, I decided to make sure my projects are finished before that happens. I don’t want to leave an incongruent mess of unfinished stuff for future space-archaeologists to decipher, if there’s something to be found on Earth after the great cataclysm or whatever it is that will exterminate us. I’d rather make it easy for them to make sense of what it was all about.

One of the first things I have finished this year is my first ever travel diary of sorts. It depicts our journey from London to Hong Kong, then Tokyo, San Francisco and finally New York this past April-May 2011, with special guests such as Aaron Koblin, Jeri Ellsworth and moot (to mention a few). It was quite entertaining to draw famous people! Although I am not sure my interpretation is very truthful, but that’s part of the fun anyway!

I just finished scanning it a couple days ago, and I’m still trying to decide what’s the best way to publish/share it. In any case, I still have to crop, align and export all the pages (the 60+ pages) so I’m pretty sure I’ll get some ideas in the meantime, either by myself or in the comments (hint! hint! hint!) ;-)