Thoughts, early 21st century

Stabilize video in Ubuntu Linux

24 Sep 2010
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ubuntu

I own a Flip Mino HD pocket video camera. The video quality is really amazing. I find it unbelievable that it's 5 times cheaper than our old 8mm video camera, uses no tapes, no cables, no charger. Nothing, but the camera itself. But it does have one problem: the camera is so light that it's hard to hold it stable, so if you are not using a tripod the result is probably shaky. One year ago I tested a popular program that corrects shaky video: Deshaker. But it's only available for Windows. After some research I found vid.stab. I tested it once with the default settings and the result is already much better than the original (see above).

How to use vid.stab under Ubuntu?

Vid.stab is a plugin for Transcode. To get it running:

Go to the Ubuntu Software Center, find and install Transcode. The current version (September 2010) already comes with the stabilization plug in, BUT it didn't work for me. When I tried using it it complained about "unsupported codec" all the time. Try it. Maybe your version already works. Skip to step 5 and if you get the error, go back to step 2.
Visit the vid.stab download page and download the latest plug in binary. Currently called "Version 0.75, binary files (linux 32bit i586), works with 1.1.X". This is a packed .tgz file that contains the plug in (filter_stabilize.so and filter_transform.so).
Unpack the plug in: you can double click the .tgz file, double click the stabilize folder, then drag the two .so files to the Desktop.
Open a terminal and move filter_stabilize.so and filter_transform.so from the desktop into /usr/lib/transcode/ overwriting the files with the same names. Type something like: sudo mv /home/YOURUSER/Desktop/filter_* /usr/lib/transcode/ (where YOURUSER is your Linux user name).
Ready to try it out: cd into the directory where your videos are located: cd /home/YOURUSER/Desktop/MYVIDEOS/
Type transcode -J stabilize -i YOURSHAKYVIDEO.mp4 (this will analyze the shakiness).
Type transcode -J transform -i YOURSHAKYVIDEO.mp4 -y xvid -o STABLEVIDEO (this will correct the shakiness).

Now you should have a much less shaky video called STABLEVIDEO in xvid format. For information about the command line options visit the Stabilize plug in web page and the Transcode web site. You can improve results by adjusting the amount of shakiness distance and duration. When will we get this kind of stability? :)

Robotlegs class diagram

I've started using the Robotlegs AS3 library to better organize the source code of my Flash map. Sometimes I have a hard time understanding diagrams and documentation. It happened when reading the PureMVC documentation, and it happened again while learning Robotlegs. I believe the documentation sometimes assumes many concepts are familiar. I find many words used are too abstract and non specific. Instead of having to read 20 or 30 pages several times, I'd like a short list with rules, a numbered list of steps required to make it work. I miss a one page long explanation, which I think is perfectly possible. I remember taking diagrams from a popular AS3 book, moving some boxes around and the result would be so much simpler, more symmetric. It was like playing this untangle game. When I first had a look at the Robotlegs diagram I didn't really get it. I found the lines with 90º turns hard to follow, and I had to search for those numbers one by one. So I remade this diagram using curved lines. I tried to make it possible to understand the code flow effortlessly, following just one line from start to end. Hopefully others also find it simpler.

source file for the updated Robotlegs diagram in Inkscape SVG format.

I hope this is seen as constructive criticism. The Robotlegs micro-architecture is an excellent piece of software. I just believe documentation can often be refactored and its dependencies from previous knowledge removed.

A treasure called Khan Academy

19 Sep 2010
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in_english khanacademy text

I have many friends who, like me, grew up in Mallorca but live abroad. We usually visit the island a few times every year. When I coincide in Mallorca with my friend Andrés we take part of a ritual: we drive with the car to the other side of the mountains. Few people live there. We walk to some lonely rocky place by the sea shore. We dive and explore the under water world, we jump into the sea from high places, we have some salty snacks and a beer while watching the sunset and listening to music, and we discuss life on this planet.

In one of these discussions a few weeks ago we talked about education. How education evolves so slowly, in part because of laws and traditions, and how education does not yet use the technology available that would make learning a more productive experience. I was proposing one idea. In my head was Carl Sagan, who was fantastic at explaining science and astronomy with lots of passion, in a way people could understand. I asked myself why do I have to be taught by anyone who is less passionate than Carl Sagan? Why do I have to be taught by someone who is not able to communicate ideas clearly, or someone who doesn't even like the topic?

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Windows automatic reboot

17 Sep 2010
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annoyances windows

I switched to Ubuntu a few months ago, but lately I had to run Windows to convert some VHS video tapes to mp4. The tapes are usually 3 or 4 hours long, so I leave the computer working at night and the work is done when I wake up in the morning.

Yesterday morning I was surprised to find the computer running Ubuntu, even I left it running Windows. A power cut? A lightning? Nah, it's a laptop... A really nasty Windows bug? I checked the video file and 30 minutes were missing from the end. I wondered what had happened, until I realized Windows had installed some updates and rebooted on it's own, even there was a program running. I find this annoying, even dangerous.

In my case this automatic reboot "feature" made me waste time. But what if I was on a deadline doing some 3D rendering? what if I expected to access this computer remotely, or if it was in charge of controlling some physical devices in meatspace? I know the feature can be switched off, but I believe it should not be on in the first place. Not like this. I'm sure this feature has caused trouble more than once to people around the world.

Two changes would make it less problematic. One: reboot only if the computer is idle. If I have a program running using a lot of resources, maybe it's for a reason. Two: send me a notification e-mail. I probably receive it on my cell phone. This way I have a clue about what went "wrong".

It looks like the developers did not consider I might not be sitting in front of the computer when it's telling me 'hey, I'm going to reboot, save your changes'. Good that I will be done converting these tapes very soon :)

Facebook: deactivate account

13 Sep 2010
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in_english mallorca photo text

Edit: this post was not readable because I used a "-" character in the title. Now it's corrected. En Español.

Last night I clicked the 'deactivate account' link on Facebook. It was an exciting moment.

A Facebook group delayed my decision a few weeks. It's a group where people from Mallorca shared links to electronic and dance music from the 90s and 2000s. It was a beautiful thing to build something with so many other people. It grew very fast, in a few weeks almost 900 members and 1700 songs. I discovered new songs, and names of songs I used to dance to. To help people avoid reposting the same songs, I built an online tool that collected all the youtube links in a list, then added a search engine. Suddenly the participants relied on this tool I was supposed to update every day. So I had to find a way to make it work without me. I tried many things. The Youtube API, the Facebook API, Firefox Greasemonkey extensions, Chrome extensions. I learned much and it was fun to play with those things and I found a way to make it continue without me. But the main question is...

Why close my Facebook account?

I could give two answers. The short one is that something inside me felt it was the right thing to do. Many times I've had this kind of feeling, but I usually don't accept it right away because it does not feel logical, it does not include a list of "why do it?" and "why don't do it?" items. In the end this initial instinct is usually correct, but I need to justify it with the long answer.

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Thoughts, early 21st century

Stabilize video in Ubuntu Linux

How to use vid.stab under Ubuntu?

Robotlegs class diagram

source file for the updated Robotlegs diagram in Inkscape SVG format.

A treasure called Khan Academy

Windows automatic reboot

Facebook: deactivate account

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