Monday, 31 December 2007

Create DVD Video using ManDVD

This is my second post on creating DVD video, on the first one I used a program called DeVeDe. Now I want to do the same using another program called manDVD. This was recommended by an anonymous comment on the other post. I really like manDVD, the step by step process makes converting to DVD video very simple. It also lets you create really nice looking menu's for your DVD. To get a hold of the program check the links at the end.

When you run the program you'll be presented with the following window. You can start a new project or load an existing one.To start a new project, first select the destination folder and then choose the standard and size of your final DVD video. Click 'Confirm' to get to step two.

Next, start adding your video files. Once you've done that you can add subtitles, define the length of chapters or even add some nice video effects. I'm going to ignore all that and go straight to menu creation.

The first step for making a menu is choosing a background. Here I have chosen a picture. You can have an animated background created from the video if you want. Next click on the 'Menu font' button, choose an appropriate font and size. You can also have music playing in the menu background, which is nice.

Next, we need to add the video buttons to the menu. Position the buttons using the sliders. Once your happy with the positions click 'Confirm button position'. Don't forget to choose whether you want it to go back to the menu or play the next video when one video ends. When your done, click 'Next' to go to the final window.

In this window click on the 'Options' button. From here you can set the video bitrate depending on whether you want good quality of a faster conversion. Once your done click the options button again to get rid of it.

The last choice to make is whether you want 4/3 or 16/9 format. Then click 'Generate DVD structure' and wait for it to finish converting.

Once it's finished you can view the result, burn it to disk or create an ISO image. As you can see from the screenshots the program isn't fully translated into English, however this is not a huge problem and shouldn't prevent you from doing anything. ManDVd is now my preferred application for converting avi to DVD in Ubuntu. Thanks to the person who recommended this.


Happy New Year

Happy new year to all, I hope 2008 is even better. We still have few more hours of 2007 left here in the UK but I can already hear the fireworks going off outside.

Effects of GSM Signals on Sleep

A story in slashdot highlights the results of a research project carried out in Sweden regarding the effects of 884 MHz GSM radiation on sleep of the subjects studied. The results show that subjects exposed to the radiation compared to placebo exposure displayed a prolonged latency to reach the first cycle of deep sleep (stage 3), the length of stage 4 sleep also decreased in exposed subjects. Moreover, participants that otherwise have no self-reported symptoms related to mobile phone use, appear to have more headaches during actual radiofrequency exposure as compared to sham exposure. The study indicates the effect of exposure on components of sleep, believed to be important for recovery from daily wear and tear, as being adversely affected.

PIERS Online

Sunday, 30 December 2007

Alternative Start Menu for GNOME

The GNOME start menu, like almost everything else, is fully customisable. On one of my previous posts I showed you how you can customise the look of Ubuntu, now I want to show you the alternatives to the standard start menu you get in Ubuntu.

Standard Menu Bar
Here's what the default menu bar looks like, you actually get it at the top but I have my panel at the bottom.

You can change the layout or even add/ remove the menu items by right-clicking on the start menu and selecting 'Edit Menus'.

Slim Main Menu
This a more compact version of the above and it's also the one I use. I like it because it leaves more space for the running programs applet.

Once again you can edit the layout of the menu items. I don't go into the start menu very often since I have all my favourite apps on the desklet at the top of my screen.

Gimme is more than a start menu, it's a whole organiser. It's jam packed with things, you can access almost everything from it. It has a search function which lets you find everything from programs, files, computers on a network and even search your friends on IM.

It is quite large but you can always remove the buttons that you do not need from preferences.

Uslab is a modified version of the menu from Suse 10. I have never used it myself but here's what it looks like.

It takes up less space than gimme and also has built in search function.


Saturday, 29 December 2007

Hardy Heron Theme Mockups

Here is a list of some interesting looking theme mockups for the next release of Ubuntu. I personally like the first one, it looks clear and fresh. It looks like Gelatin, as the first one is known as is being officially considered a candidate for Hardy Heron. You can also download it from here. It needs a little bit of polish but overall I think they are heading in the right direction with this theme.

Thursday, 27 December 2007

Ubuntu Bluetooth Remote Control

I have a Sony Ericsson K800i phone and one of its coolest features is the ability to control your pc using bluetooth. It's pretty straightforward in Windows but Ubuntu needs a little bit of work to get it going. Open up your terminal and follow the steps below.

  • Install bluez-utils, Gutsy comes with this installed but here's how you can install it if you don't have it
sudo apt-get install bluez-utils

  • Next let's search for our phone
hcitool scan

  • You should see your phones MAC address and identifier appear, something like this
00:11:22:AA:BB:CC MyPhonesName

  • Now, copy the MAC address of your phone and enter the following
sudo hidd --connect 00:11:22:AA:BB:CC

Your phone should now ask you if you want to allow remote control, select yes and your ready to control your Ubuntu. Unfortunately you have to do the above every time you want to use it. To control your media applications such as Totem or amarok you need to download certain configuration files to your phone. For a list of compatible phones and the configuration files check out the link below.

ubuntu forums

Wednesday, 26 December 2007

Nanosolar: Solar Power for the Masses

Nanosolar, a Silicon-valley start-up has managed to do what a lot of people have been trying for a long time: they have developed solar cells which create energy that is cheaper than burning coal. That is a huge achievement considering cost was the biggest drawback for solar power generation.
What differentiates Nanosolar from others is that they focused on the manufacturing process instead of just increasing efficiency of the cells. The result is that they have managed to reduce the cost per watt to an amazing 33 cents. They plan to sell at $1 per watt, making them a tidy bit of profit.
They are using a mixture of Copper Indium Gallium Diselenide, which can achieve an efficiency of 19.5%. Others are also using the same mixture of elements as an alternative to Silicon, Silicon is a poor absorber of light and therefore the wafers must be thick. The new mixture allows coatings to be very thin and still convert energy at a good efficiency.
The company plans to begin full production in 2008.


Tuesday, 25 December 2007

Euler's Prime Generating Equation

In the eighteenth century, Leonhard Euler discovered (no one knows how) that the equation

produced primes consecutively when fed with numbers n=0 to 39. Even though the equation fails when n=40 it still manages to spit out more prime numbers than any other quadratic equation. Of the first 10 million values the proportion of primes is about one in three. Euler then showed that you can substitute 41 with k=2,3,5,11,17 and the formula

would still produce primes from n=0 to k-2. To show you why this equation is so special I'm going to first solve the quadratic equation for all the values of k.

The numbers 7, 11, 19, 43, 67, 163 are what make the equation special, but what's so specials about these numbers you ask?

Gaussian Integers and the Class Number Problem
In 1796 Carl Friedrich Gauss proved a theorem called the quadratic reciprocity law, which concerns the solutions to equations of the form

where p and q are prime numbers. Gauss found that his calculations were made easier if he worked with numbers of the form a+bi, where a and b are integers. These numbers are now known as Gaussian integers. These numbers turned out to be very useful in other areas of maths. Gauss then investigated other systems with which you could create a 'number theory' out of, one of the systems he looked at was of the form

where d is some integer other than 1. Here is a list of the values of d which produce a unique factorisation theorem.

d=1, 2, 3, 7, 11, 19, 43, 67, 163

Notice anything familiar? In 1952, Kurt Heegner managed to prove that d=163 was the biggest value that could make it work. And so there is the reason why those numbers and that equation are so special.

Recommended reading:
"Mathematics: The New Golden Age", Keith Devlin

Asus LS201: Arrow proof monitor

The Asus LS201 is not like your average monitor, it is protected with a panel made out of crystal-sapphire which makes it not only scratch proof but hammer, nail and arrow proof. I'm not sure how useful that is but here is a video of some Ukrainian guy testing it out.

My Ubuntu apps

I just thought I'd list some of the programs I use in Ubuntu, most Linux folks would probably have the same or similar list.

I do most of my browsing with firefox but I also use Opera now and again.

I made the banners for this blog using Gimp, not bad considering all I've used Gimp for previously is cutting and pasting.

For converting my avi files to dvd, read more about it here.

A fully featured CD/DVD authoring application. I often used it to burn the DVD's I made using DeVeDe.

I do all my uni work with it.

Backs up my important files and folders, read more here.

For downloading stuff.

For running uTorrent among other Windows programs.

Pidgin is a multi-protocol instant messaging client.

For times when I just can't avoid Windows.

Totem movie player
Watch all my videos on this.

An audio editor and recorder, I mainly use it to make ringtones from mp3's.

I found it really annoying when I used to lose everything I copied or cut by closing the application I got it from.

I hope this helps anyone new to Ubuntu/Linux. The best thing about this list is that all the applications are free.

Monday, 24 December 2007

Gambas, Visual Basic for linux

The first computer language I learnt was BASIC. I taught myself using the examples on my first computer, a VTech(can't remember the exact model). I remember thinking how easy it was to learn and use, I wrote my first program after about a week, and it was to solve equations for my maths and physics school homework. Even though I later learnt C and a little bit of python I still used visual basic whenever I needed to make something really quickly. However, after I ditched windows for ubuntu I started looking for something to fill the gap, that's when I stumbled upon Gambas.
Gambas is a graphical development environment based on a BASIC interpreter. It may be similar to visual basic but it's not compatible with it. Here's some of the features as listed on the website.
  1. A Gambas project is stored under one directory. The archiver transforms the project directory structure in one sole executable file.
  2. Compiling a project only requires the compilation of the modified classes. Every external reference of a class is solved dynamically at the execution time.
  3. Gambas has a component architecture that allows to extend the language. Anyone can write components as shared libraries that dynamically add new native classes to the interpreter. Component can be written in Gambas too. The component architecture is documented in the Wiki encyclopaedia.
  4. By default, the Gambas interpreter is a text-only program. The component architecture is used for writing the graphical user interface part of the language.
  5. As the graphical user interface is implemented as a component, Gambas will be able to be independent of any toolkit! You will be able to write a program, and choose the toolkit later : GTK+, Qt, etc.
  6. Any window or dialog box can be used like a control. You cannot do such a thing with Visual Basic without using ActiveX.

Some shots of it in action.

You can get Gambas by entering the following into your terminal.

$ sudo apt-get install gambas

For more on Gambas check out the website.


Sunday, 23 December 2007

Wipe files/folders using Nautilus-actions

Here's how you can add the wipe command to your right-click menu using Nautilus-actions. This will enable you to securely delete one or more files/folders without having to use the command line. To install Nautilus-actions, enter the following in your terminal.

$ sudo apt-get install nautilus-actions

If you don't have the wipe command installed already, you can get it using the following command.

$ sudo apt-get install wipe

Nautilus-actions is located under System>Preferences menu. You'll get the following window when you run it. To add a new action simply click on the 'Add' button.

Next, copy everything you see in the following two windows.

When your done click the OK button and close Nautilus-actions. Now you should see 'Wipe selected' command appear when you right-click on a file or folder. You will not be asked for confirmation when your wiping a file/folder so use with care.

Saturday, 22 December 2007

Robot that can learn

HOAP-3, a robot made by Fujitsu, can learn new tasks thanks to software created by Sylvain Calinon at the Swiss Federal Institute of Technology. It can learn by watching someone demonstrate a task or through kinesthetic teaching. It gets better at a task the more times it does it by refining it's movements through self observations. It can even draw portraits of people it recognises. Looks like our days are numbered. For more information and video's of the robot learning check out the link below.

Sylvain's website

Linux MCE demo

Here is an impressive demo of Linux MCE, it is a media centre and home automation system with some amazing features. I'm going to download and install it myself.

Linux MCE

Friday, 21 December 2007

Convert AVI to DVD in Ubuntu

When I first started using Ubuntu, one of the things I found tricky was video converting. In windows I used to use winavi. Then I discovered a program called DeVeDe. DeVeDe is an open source program that you can use to create video DVD'S or CD'S. It supports popular formats such as avi, mpeg, wmv, quicktime, ogg and others.
To install the program you can either use the 'Add/Remove Applications' menu or use synaptic. Alternatively you can enter the following in your terminal.

$ sudo apt-get install devede

DeVeDe is located under the 'Sound & Video' menu. Once you run it you will see this window.

Here I'm going to use it to make a video DVD.

Firstly, choose the size of your dvd disk and then start adding your video files by clicking on the Add button to the right. You can have a title per video file or have more than one video file under the same title. Here I'm just going to be converting one video file.

Once you have selected a file you will see its information displayed on the window above. Now you can choose the video and audio rate to your desired values. I have found that the default values can result in a slow conversion, I have tried setting it to the same value as the original avi with decent results but it's up to you. Make sure to have the correct 'Output video format' for the tv you use. Next, click on the 'Advanced options'. Here you'll have the options for video, quality, audio and subtitles.

Under 'Video options' you can choose the size of the video, add black bars or scale it and you can also select to use 16:9 aspect ratio. Under 'Quality options' the default is set to good quality conversion, if you want a fast conversion deselect 'Use Trellis' and select 'Use MBCMP'. If the sound is not synchronised with your video you can use the 'Audio options' to add a delay to the audio. I'm going to ignore the subtitles option but it is very straight forward if you do need to use it. Finally the 'Misc options' lets you set the intervals you want to split the video in to chapters. There is a preview button on the left corner which lets you view the video so that you can change anything you don't like. Once your happy with the settings click OK to get back to this window.

A nice feature of DeVeDe is the ability to create an ISO file for easy burning or if you want to view your video before burning select to create mpeg files under 'Actions'. The final thing to do is click 'Forward', choose the output folder and a name for your video and wait for it to finish.

Once it's finished you can use programs like GnomeBaker or K3b to burn it. Although DeVeDe is very easy to use, I personally prefer ManDVD, it provides a more straight forward step by step process. Check it out here.

Thursday, 20 December 2007

Favourite gadgets of 2007

This year has been pretty big in terms of gadgets. Here, in no particular order, is a list of some of my favourite.

I'm not really a fan of the iphone but I can't really ignore it. In terms of gadgets 2007 will probably be remembered by most as the year of the iphone. Its in Time magazines gadget of the year list. The things I like about the iphone is its huge touch screen, cool user interface with a mini version of os x and the excellent build quality. The downsides for me is the 2 megapixel camera, the price and the non-open platform. I have a Sony Ericsson k800i which has a 3.2 megapixel camera and I wouldn't buy a phone which has anything less specially after how useful it was on my holiday. The iphone has definitely got the other manufacturers to sit up and take notice, which is a good thing. Its definitely a beautiful looking phone, better looking than anything else out at the moment.

LG KU990 Viewty
Its no iphone but it can hold its own with a 5 megapixel camera and an array of other cool features. Read more about this phone here. It doesn't have to same build quality or multi-touch user interface but it is a lot more affordable.

PlayStation 3
No matter what problems its been facing the ps3 is an awesome machine. It has demonstrated its power when it tripled the computing power of folding at home, surpassing all the other clients. I think we have yet to see the full potential of the ps3 and 2008 should be a better year for it.

Asus EeePc
This years also been about small cheap laptops, first there was the OLPC and then the eeepc. The features of this include 7in screen with 800×480 resolution, wifi, linux os, 512 MB DDR2 memory, 900 MHz Intel Pentium M CPU, It has solid state memory and comes in 4GB and 8GB versions. You can pick one of up these for about £200.

Nintendo Wii
This is probably top of most peoples Christmas list. The wii is so popular that Nintendo has been struggling to cope with demand. Nintendo even had to remove some ads because it doesn't really need them to sell this thing.

Tuesday, 18 December 2007

Sum equals product

love investigating patterns in numbers and shapes, I particularly like finding equations describing the patterns. Few years ago, while working on a maths assignment, I wondered if the number 2 is the only number that gives the same answer when added together and multiplied together i.e 2+2=2*2=4. It seemed obvious that 2 had to be the only number that you can do this with, but was there other numbers that when added together N number of times would give the same result as being multiplied together N times. So I decided to investigate and see where it leads me. I originally called the results of these sums and products 'perfect numbers P' , but I later realised that perfect number was a name given to something else.
I'll start with defining what the number P is, P satisfies the following:

Where N is the number of terms and x is the number we're adding and multiplying together. If we equate the above two and rearrange to get:

From equations 3 and 4 we can immediately see that N cannot equal zero or one otherwise we get undefined results. I'll show you later how N can approach 0 and 1 to give some nice results but first I want to use equations 3 and 4 to produce some values of x and P.

Dx and Dp are the difference in the values of x and P respectively. From the table we can see that Dp seems to be converging to 1 and Dx is converging towards 0. This tells us that as N goes to infinity so does P, x however is converging towards a single value of 1.
Now lets consider what happens when N=0. We already know that we can't just enter 0 into the equation, but we can sort of cheat and say what happens when N=0+h where h can be as small as we like, or to put it another way the lim(0+h)=0 as h approaches 0. If you can remember your basic differentiation you'll know what I have done there. So if we put this new value into equation 4 we get P=1. A far more interesting result is obtained when we apply the same method to N=1. So once again the lim(1+h) = 1 as h approaches 0. Now if you put that into equation 4 we get p=e where e is the base of the natural logarithm also known as Euler's number. I don't know about you but I find this result amazing. We can also do the same thing for x. When N=0+h we get x=infinity and when N=1+h we once again get the number e. One final bit of observation from the results is that P starts from 1 and goes to infinity whereas x starts from infinity and goes to 1.
I realise that this is not very mathematically rigorous but I hope you can appreciate the results. I have not worked on this any further so if anyone else finds any more interesting results please let me know.