Freej beginner tutorial
Target of this manual
In this part you will learn:
what is the basic idea of using freej, how its user interface is organized
how to use freej to show movies and static images
- how to use layers, so you can use more than one movie
- how to mix layers with each other
- how to add visual effects to displayed movies
However, we assume that you:
- can use a GNU/Linux system (command line)
will really do all the exercises from this tutorial -- if you only read it, you'll learn nothing. You have to put hands on!
- will let us know about any problems, comments and suggestions, so we can make this tutorial better
contents
the first start -- how to start and stop freej
user interface -- what is what in freej
mixing two movies (fun starts)
using effects -- basics
effects disabling and deleting
the first start
Create a directory, for example freej_tmp. We will put our images, movies etc in this directory and we will play inside it:
mkdir freej_tmp cd freej_tmp
Download this image to freej_tmp directory. Now start freej:
freej ipernav.png
As a result, freej starts and shows the picture ipernav.png.
user interface
Freej consists of two windows:
- output window – in this window our movies, pictures etc are shown,
console window – this window is used to interact with freej – give commands, load new pictures, movies etc,
In console window, press ctrl-h. You will see the list of shortcuts.
As you can see, [ctrl+c] means quit. Press [ctrl+c]. You are prompted to confirm that you really want to quit freej. Type yes [enter]
some more fun – movies
So far we just used static image – not so much fun. But the very same way we can use a movie.
Download this movie to freej_tmp directory. Then start freej:
freej kury.avi
As a result, freej starts and shows the movie kury.avi.
quit the freej (remember? [ctrl+c]).
more layers
We can load both static image and the movie.
Start freej with both movie and static image:
freej kury.avi ipernav.png
As you can see, only chicken movie is visible (and the static image – file ipernav.png – is invisible). We are going to understand why...
Now, when we opened two images (static image and a movie) in freej, we have them on two layers.
You can see the list of layers in the console. As you can see, that layers are called VID (which means: video layer) and IMG (static image layer).
The list of layers is also shown in output window. As you can see (below), the video layer is on top of static image layer. This is why we can't see the image.
Take a look at the console window. As you can see, one of layers (VID) is highlighted. It is the current layer. You can see the detailed information about that layer in the top of console window.
You can see there the name of the file (kury.avi) and some other info, which we will understand later.
Notice that current layer doesn't mean top layer or the layer which is visible now. Current layer means just current layer.
While in the console window, you can use left and right arrow keys to change the current layer. Press the right arrow key to change the current layer to IMG layer. Notice that now at the top of the console window you can see the details of static image layer.
While in the console window, you can use + and - keys to move the current layer up and down. So now, when the current layer is IMG layer, press +. As you can see, the static image layer went to the top. Now the static image is visible and the chicken movie became invisible.
Close the freej (ctrl+c, as you remember).
some words about commands, parameters, completions
Some of the console commands (e.g. CTRL-B, CTRL-E) can accept parameters. To show them, just press TAB. The completion is also working.
For example, pressing CTRL-B you have:
[*] select Blit mode for the selected Layer - press TAB for completion:
and so, pressing TAB, you obtain:
[*] List available blits starting with "" RGB ADD SUB MEAN ABSDIFF MULT MULTNOR DIV MULTDIV2 MULTDIV4 AND OR XOR RED GREEN BLUE REDMASK GREENMASK BLUEMASK NEG ADDB ADDBH SUBB SHL SHLB SHR MULB BIN SDL ALPHA SRCALPHA CHROMAKEY
When choosing something, like a filter (pressing CTRL-E), you can also use TAB and completion:
[*] add new Effect - press TAB for completion: 3dflippo Brightness bw0r Cartoon Contrast0r delay0r Distort0r Equaliz0r Flippo Gamma Glow Hueshift0r Invert0r Mask0Mate nosync0r pixeliz0r rotozoom Saturat0r scanline0r Sobel Squareblur TehRoxx0r Threshold0r Twolay0r Vertigo Water
This also give you a list of all effect.
mixing two movies
As we previously told, freej is about mixing images. Now we will start doing that.
Download another movie to freej_tmp directory. Then start freej:
freej term.avi kury.avi
As a result, freej starts. kury.avi is on the top layer, and is visible. term.avi is on the bottom layer and thus is invisible.
Now press key CTRL-B, and write red in output window. The effect should look like that:
Doing so, we made red blit on active layer. You can see it in layer details, in the top of console window.
As you know, each picture an a computer screen has three channels: red, green and blue. Red blit means that now only red channel of the kury.avi layer is visible. Green and blue channels of this layer became transparent, so now we can see:
the red channel of kury.avi
the green channel of term.avi
the blue channel of term.avi
In very similar fashion we can use green blit or blue blit, just choosing green or blue as parameter for CTRL-B. You can also try using other blits in the list. Try switching it on and off! 
alpha blit
And now let's try alpha blit!
As you can see, now we use alpha blit (you can read it in the info on current layer in the console window). With alpha blit, the current layer becames partly transparent. As you can see, now the layer kury.avi became fully transparent and only term.avi is visible. This is because alpha parameter is zero:
We can change the alpha parameter from the console window. Just press CTRL-V and you can change the alpha numeric value. Enter a value between 0.0 and 0.1, for instance 0.5 – the current layer becomes half transparent.
Effects
Start freej with term.avi:
freej term.avi
In console window press [ctrl+e] (e like effect). You will see the prompt like that:
So just press [tab] and you will see the list of available effects:
Vertigo effect is a nice one. So just type vertigo [enter]. You will see something like that:
disabling and deleting effects
Take a look at the console window. As you can see, the current layer is video layer with file term.avi:
You can also see that this current layer has the effect vertigo:
Press down arrow key in the console window to see the details on this filter:
Pressing SPACE key you can temporarily disable and enable this effect. Press [delete] to delete the effect from this layer.
about this document
The original document was by Piotr Sobolewski (http://www.rozrywka.jawsieci.pl/materialy/index_EN.html)
It was revised, enlarged and rebuilt at Wintercamp 09 in Amsterdam, by Gabriele Asbesto Molesto Zaverio.
It was revised, and rebuilt once more for the 1.0 release by Alexander "dreamer" Chalikiopoulos.