Install Ruby if you have not. And install AviGlitch through rubygems.
$ sudo gem install aviglitch
We'll show some code examples here. Before that, there is something you need to know.
The input file must be an AVI formatted file. AviGlitch doesn't provide any file converting function, use ffmpeg or something to make an input sample.
We recommend making the input file in small size (5 mins or shorter) for saving your machine power and executing time.
If you use Ruby 1.8.x, you must
require 'rubygems' on the top of code lines.
And what we do is basically an illegal operation for the file and the player application, try codes at your own risk.
At first, let's do a simple glitch that is known as datamoshing. Datamoshing means key frames removed video. You can see in the code below that AviGlitch provides an easy way to remove key frames.
require 'aviglitch' a = AviGlitch.open 'file.avi' # Rewrite this line for your file. a.glitch :keyframe do |f| # To touch key frames, pass the symbol :keyframe. nil # Returning nil in glitch method's yield block end # offers to remove the frame. a.output 'out.avi'
This code will generate a video like this.
The AviGlitch library includes a command line tool named
datamosh command does same thing as the code above. Without any coding, in the terminal, simply type;
$ datamosh file.avi
This is the world's easiest way to make a datamoshing video. If you like a complex and messy way, learn from this guy.
Next is an example of the frames manipulation. It's bit complicated. Following code makes a certain frame repeated a number of times.
require 'aviglitch' a = AviGlitch.open 'file.avi' # Rewrite this line for your file. d =  a.frames.each_with_index do |f, i| d.push(i) if f.is_deltaframe? # Collecting non-keyframes indices. end q = a.frames[0, 5] # Keep first key frame. 100.times do x = a.frames[d[rand(d.size)], 1] # Select a certain non-keyframe. q.concat(x * rand(50)) # Repeat the frame n times and concatenate with q. end o = AviGlitch.open q # New AviGlitch instance using the frames. o.output 'out.avi'
It makes a beautiful glitch like this.
Next example uses a pretty neat trick. Following code overwrites key frames' screen size data randomly.
require 'aviglitch' a = AviGlitch.open 'file.avi' a.glitch_with_index(:keyframe) do |data, i| x = data[25..28].unpack('B*').first w = rand(('0b' + x[0..12]).oct * 1.5) h = rand(('0b' + x[14..26]).oct * 1.5) x[0..12] = "%013b" % ((w > 50) ? w : 50) x[14..26] = "%013b" % ((h > 50) ? h : 50) (i == 0) ? data : data[0..24] + [x].pack('B*') + data[29..data.size] end a.output 'out.avi'
And to play the result output with the VLC player, it becomes like this.
It completely depends on the VLC player application and the Xvid codec. It doesn't work with other player and codec combinations.
At last, we will show the achievement of excess glitches using ffmpeg, mencoder and AviGlitch (and no Adobe stuff).
For more details, read the documentation.