Pete’s blog

F1 Flexi Wings Saga

For some time now one of the most intriguing stories unfolding in Formula 1 is the Red Bull Flexi Wing saga. What is the case? In Formula 1 both front and rear wings have to adhere to specific requirements to be compliant with the rules. One of these requirements is that the wings should not flex too much. Flexing wings are deemed dangerous as they could break off, changing the characteristics of the car radically and thereby bringing the driver in immediate danger of loosing control of the car.

For some time now this season Red Bull is suspected to be using flexible wings - read more here - and of course they deny it. Some pictures however are looking to be very compelling evidence that they do flex.

So the question is, what is going on. Today I read an eye-opener. How do they test the wings on flexing? They put 100kg on each side of the front wing, 200kg in total! Now to put this in perspective, a Formula 1 car’s wings generate several times their own weight in down-force. At >190km/h the down-force is already 2x it’s weight 2×650kg=1300kg! (read here). The front wing bears about 25% of this amount, being in total 325kg at 190km/h. So at higher speeds it is even more!

So to really test Red Bulls Front Wings (and others for that matter) more than 325kg is needed and not 200kg! Let’s see whether more people find this fact (especially within F1!).

iPad HTML5 design

Since a little bit I have been playing with the new Apple iPad and I have to say it is great. As a technology lover and hobby programmer, of course I had to dive in and test a view things myself. The first thing that cought my eye was the rotation and possibilities it gives for webdesign and therefore I was very surprised to learn that this is already supported in the new HTML5 (draft?) spec.
Anyways I want to share how you can make a page that looks different based on how you hold your iPad, which is actually quite simple.
You need two style sheets, one for each orientation of your iPad. Lets call them portrait.css and landscape.css. In your head definition of your page you put:

<link rel="stylesheet" media="all and (orientation:portrait)"
href="portrait.css">
<link rel="stylesheet" media="all and (orientation:landscape)"
href="landscape.css">

Also helpful if you want to start defining absolute sizes for your sheets depending on how you look at them, you can use:

<meta name="viewport" content="initial-scale=1.0">
<meta name="viewport" content="maximum-scale=1.0">
<meta name="viewport" content="minimum-scale=1.0">

With a quick definition of portrait.css and landscape.css you are now able to transform the look of your page based on the orientation!

In a follow up post, I will add some examples and also some other useful JavaScript I found that helps in making more advanced pages.

Enjoy!

Google Chrome on Slackware

Thanks @bartv I was just remotivated to try and get Google Chrome working on Slackware. A previous attempt did not work and also this attempt took some work, so I decided to share it for other potential Slackware users.

Based on knowledge from this blogpost I made a few packages that should be easy to install and get you going.
These are based on ORbit2 and GConf from Slackbuilds and the original Google Chrome RPM (version 4.0.249.43). I used rpm2tgz to get the contents and then modified the doinstall script to not only install, but also copy the google-chrome.desktop file to /usr/share/applications and /usr/share/apps/kappfinder/apps (assuming you are using KDE).

For you, all you need to do is download these 3 packages and run installpkg on them. Pretty simple.

• ORBit2-2.14.17-i486-1_SBo.tgz
• GConf-2.26.0-i486-1_SBo.tgz
• google-chrome-4.0.249.43-i486.tgz

There is one important assumption in the Chrome package, which is that Firefox needs to be installed in /usr/lib/firefox (this is standard in Slackware). The install script of Chrome makes a few symbolic links needed to make things work. If you get library errors it is worthwhile to check whether the symlinks are made.
Goto /usr/lib/ and check for the following:

libssl3.so.1d -> /usr/lib/firefox/libssl3.so
libsmime3.so.1d -> /usr/lib/firefox/libsmime3.so
libplds4.so.0d -> /usr/lib/firefox/libplds4.so
libplc4.so.0d -> /usr/lib/firefox/libplc4.so
libnssutil3.so.1d -> /usr/lib/firefox/libnssutil3.so
libnss3.so.1d -> /usr/lib/firefox/libnss3.so
libnspr4.so.0d -> /usr/lib/firefox/libnspr4.so

Hope you succeed, if you do you can let me know on twitter.

Peter

New game - call of duty modern warfare 2

It has been a long time since the last blog and I feel this has to change. So from now on, new content every week or perhaps more. My intent is to blog about my hobbies and the cool stuff we are doing over at shapeways

For today it is simple. Last weekend I bought a new game called Call of Duty - Modern Warfare 2. Reviews can be found here. The game is almost photo realistic and if you like a tactical shooter, check it out. The day you are part of your own movie are not far away. More to follow.

File syncing with Unison how-to

Just updated the Tech-notes pages with a short HOW-TO about using UNISON. It is an excellent way to sync two document roots across the internet.
If you find yourself behind different computers and struggling with current versions of documents it is an excellent tool. Look here for more info.

My page is located here

Where I work

It is about time I get a bit more concrete about where I work. Just over a year ago now, I got a new job as venture owner at Philips’ Lifestyle Incubator. The Lifestyle Incubator is part of Philips Corporate Technologies.

The idea of Incubators was conceived by the previous CTO of Philips. It allows new ideas or technologies coming from every part of Philips to form into solid businesses. These new businesses can become a part of Philips or if they are not a strategic fit can go outside and become independent companies.

The venture of which I am CEO is called shapeways. You can find us at www.shapeways.com. Shapeways allows you to upload your 3D models (CAD files) to our site. They can be shared and previewed and if you want we will produce them for you using so called Rapid Prototyping. This is a technique which can be described as 3D printing.
If you want to see how it works click here

After a year we are currently testing the service in a closed beta. So, if you are interested do not hesitate to sign-up using the beta-signup.

More to follow…

MP4 for the iPod-touch

A quick post about making videos for the iPod-touch.
Just recently I bought one of these little machines and quite frankly they are great! Of course I wanted to upload some of the
video content I already had and it took some figuring out to get it to work (especially because I wanted to get it to work using linux and ffmpeg). To prevent some of you the same trouble here my findings.

First: The format you need for the iPod is mp4 (h264) with aac audio.

Second: have a look at this excellent post from Robert Swain: here

Third: be carefull with the frame rate. The iPod does not like “23.96542-like” frame rates. So if you have a file with a frame rate like that, specify it like 23.96 or something.

Last: here the ffmpeg command line params I use (based on Robert’s post)
I use two pass encoding

ffmpeg -threads 2 -i "$file" -vcodec libx264 -b $VBITRATE -deinterlace -r $fps\
-an -flags +loop -cmp +chroma -partitions 0 -me epzs -subq 1 -trellis 0\
-refs 1 -coder 0 -me_range 16 -g 300 -keyint_min 25 -sc_threshold 40\
-i_qfactor 0.71 -bt $VBITRATE -maxrate 768k -bufsize 2M\
-rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 -qmin 10\
-qmax 51 -qdiff 4 -level 30 -passlogfile "$file".log -pass 1 "$file".tmp.mp4

ffmpeg -threads 2 -i "$file" -vcodec libx264 -b $VBITRATE -deinterlace -r $fps\
-ab 112kb -acodec libfaac -ar 44100 -ac 2\
-flags +loop -cmp +chroma -partitions +parti4x4+partp8x8+partb8x8 -me umh\
-subq 5 -trellis 1 -refs 1\
-coder 0 -me_range 16 -g 300 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71\
-bt $VBITRATE -maxrate 768k -bufsize 2M -rc_eq 'blurCplx^(1-qComp)'
-qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -level 30\
-passlogfile "$file".log -pass 2 "$file".tmp.mp4