Monday, 27 February 2012

Raspberry Pi

The Raspberry Pi Foundation is a UK registered charity (Registration Number 1129409) See Website
The Raspberry Pi is for me an ideal computer. I started computing with a TRS-80 in 1980. When I bought that computer and switched it on my Mum, said what is this,  ask it who was the Queen of England in 1654?

Now that machine would only do BASIC and only what I could program it to do. Before I could do anything I had to learn to program. Within a few weeks I was writing complex programs to do all sort of things.  As a computing teacher I have had many students in my class who could use a computer , but whom had no idea about what you could get a computer to do.

I feel like many that this computer is a great step forward by taking a few steps back.

I sat in ignorance of this computer until this morning when Linux Format came through my postbox.

This seems the ideal computer for education. A small Linux platform and a simple programming language. Costing $35 dollars for 256Mb RAM, 2 USB port, an Ethernet port, an ARM1176JZFS, with floating point, running at 700Mhz, and a Videocore 4 GPU. The GPU is capable of BluRay quality playback, using H.264 at 40MBits/s..The Raspberry Pi measures 85.60mm x 53.98mm x 17mm, with a little overlap for the SD card and connectors which project over the edges. It weighs 45g.

The first shipments are with out a case which makes the computer look more like a machine that can be played with, than a black box. Later versions will have a case.

The computer has no keyboard ( so one needs to be supplied ( although it would probably fit inside one, no monitor ( any HDMI monitor TV will do) or disk. The OS is on a 16Mb or 32Mb full size SD card. The power is from 4AA cells or a small power supply a a mini 5V USB  (phone style) connector.

There is already an enthusiastic following and video's up on You Tube to look at.

At the launch in a week or so's time there is another addon board, (the Gertboard) which will allow the user to use GPIO ( General Purpose Input and Output) and the ability to add any other hardware to the computer for a truly fantastic IO  experience.

Because of its small size this computer will probably find its way into all sorts of other hardware, becoming  the computer controller  for many familiar devices.

Many years ago I was involved in creating a Beowulf cluster. With the Raspberry PI this might again became a great possibility. My students learnt an enormous amount from being able to build such a cluster. By having small inexpensive computers the way to opened up to users to discover how all types of computer systems work. Instead of having to buy several servers, the same systems could be created for well less than £100.

What can the added to the system.

Would be developers are talking about adding touch screens and other devices to the Raspberry. The appeal is a machine that is very basic - that will teach the basics of computer hardware and software. The appeal of this machine might just see it appearing in every device you can think of.

Thursday, 23 February 2012

Basic Editing

A few features about basic editing.


The Free Versions

Windows Movie Maker - The Windows 7 version is not as good as the previous versions. It is possible to download and install a previous version instead.

VideoPad Free quite goodhas many of the features of other expensive programs

Sony  Vegas
A lite version often comes with some of the cameras.

Adobe Premier

If you can record the same scene from two different angles. Use 2 cameras. If you only have one camera then do the scene twice and video it from different angles. If the scene is a success then try it again. Two copies of the same thing is useful because one is always so much better than the other.

Tips for Video Production Editing

  1. Know your footage intimately.
    Look at all the video you have taken including all the bits that went wrong, although a take may have gone wrong there might be some good parts that you could use. Collect any still photographs  that might be used to cut to whilst the narration continues.

  2. Lay-out the key elements of your film.
    Start placing all the best parts on the timeline and watch them through in its rough form to start “feeling” what works.  This is where most people finish and say this is the final item.

  3. Start building the basic structure.
    Narrow down your story into a beginning, middle and end.  Keep the video as short as possible. At this time videos normally get longer and longer.

  4. Create a great beginning.
    Most videos are made or not in the first few moments so try to make the first few seconds the best you can. A good video captures the audience’s attention right away!

  5. Watch the Adverts
    Often in the middle of a program, the adverts creep in. In 15-30 seconds these adverts tell a story and get a message across. The Scenes are quick - perhaps only a few seconds. Now apply this to your video. Add more scenes and make them shorter. Changing the viewpoint makes the video more exciting even when it isn't. Raely do you watch one viewpoint for more that a few seconds.

  6. Refine and Re-edit
    The only rule in video production editing is to do what WORKS. Keep Refining and re-editing the video until it’s right. If in doubt - cut it out. Once it is perfect. Save everything. Produce a final copy, so it to someone not involved in the project. Watch their reaction.
  7. Refine and Re-edit
    Edit the video again. Put all the things right, Save, produce the final final copy and show it to someone else. They should be happier than the first audience.
  8. Show it to the world
    Load your video onto You tube

Monday, 6 February 2012

7 Stages in making your first video blog

Now the easiest way of doing your first video is to use the webcam and just record yourself. Most of us do this, or we use the video camera in the mobile phone to record us or something going on around us.

I want to look at the next stage in making a simple video. I singe scene - no editing - just a short little video with some naration.

Stage 1 The script
This doesn't have to be wonderful or detailed, but before you start you need to have some idea of what you are going to say.

Stage 2 Set up the Stage
Put up the green screen, or any other background and get is flat and smooth. My green screen is a piece of material and each time before I use it I need to iron it to get out the creases and then I need to hang it so that there are no creases visible in the area I am filming.

Stage 3 Set up the Lights
If you are going to us a green screen or any other background then you need to get some lights onto the background.
Set up the subect away from the background and then set up the lights on the subject so that there is no shadow cast on the background.
This doesn't need expensive lights.
When my wife is out I often use the kitchen. With the green screen placed behind the kitchen fluorescent light I get fair illumination of the green screen and then I sit far enough away To light the subject I use either just a reflector or a place a couple of small lights at 45 degrees to the subject so that they do not cast a shadow on the green screen.

Stage 4 Set up the  camera/Video
If you are like me your camera is the video as well. Place this on a tripod several feet away. You want to take the image so that it is not using too much of a wide angle as this distorts the picture.

Stage 5 Rehersal
Now everything is set up. Go through what you are going to do. Do it with the video recording if you want.

Stage 6 The Take
Now you have practiced. Go for the take - or two or three or more until you manage a perfect one.
If you can do it try the same take but from a different angle. Its great to change the viewpoint  when editing.

Stage 7 Saving
Once the video is recorded then save it to the computer in a suitable format.
What is the best format? Mov, wmv or mp4.
Using videopad it doesn't matter too much and the subject of a later blog.

Thursday, 2 February 2012

Software and Hardware for video creation

More and more people these days are turning to making their own videos and vlogs.
Its easy with a camera phone and some simple editing.
The next stage is to make the video slightly more up market using some simple techniques. The first thing you need is some slightly better but free software.
To create the video software such as VideoPad Video Editor at is an excellent piece of software to get you started.
For the sound, You may want to exract sound so a program such as AoA Audio Extractor (Free) at is another bargain. Armed with better software you can now create a better movie.

The better movie requires a script and a design. I also invested in a green screen on ebay for £20 or so and with a suitable camera on a tripod we are ready. The rule of a tripod is simple. You always use a tripod except for the time you want to make a really terrible movie. The background and the foreground need to stay still.For sound recording you can either use the camera and I would always recommend adding a sound track at the time the video is made ( It can always be removed) but this often serves to identify what you are doing. I have a Sony digital recorder which produces excellent quality recordings and once the lip sync is mastered this proves invaluable.
I invested in a Kodak  Play water proof video camera. It produced HD movies and has the advantage in the Britsh weather of being waterproof.

This is a bit up from producing a simple mobile phone video bu the difference is amazing.

The best part of the Videopad software is that it can enable the use of green screening, to produce a still or video background to what you are doing.