Screengif

A commandline tool to convert SCREENCAST.mov into ANIMATED.gif

Here's what happens when you apply it to demo.mov

Usage

screengif.rb - Convert your screencast into a gif.
Usage:
	screengif.rb [options] [--input FILENAME.mov] [--output OUTPUTFILE.gif]
Examples:
	./screengif.rb --input demo.mov --output out.gif
	cat somefile.gif | ./screengif.rb --progressbar --framerate 10 --delay 50 --delay-last 5 > out.gif

Specific options:
    -i, --input FILENAME.mov         Use ffmpeg to convert FILENAME.mov into PPM image stream and process results.
                                     If missing, will process PPM or GIF image stream from STDIN.
    -o, --output FILENAME.gif        Output resulting GIF data to FILENAME.gif. (defaults to STDOUT).
    -p, --progressbar                Overlay progress bar on the animation.
    -d, --delay MS                   Animation frame delay, in tens of ms. (default: 10)
        --delay-last MS              Animation frame delay of last frame, in tens of ms. (default: 50)
    -r, --framerate FPS              Specify amount of frames per second to keep. (default: 10)
        --max-width PIXELS           Output image max width, in pixels. (default: 600)
        --max-height PIXELS          Output image max width, in pixels. (default: 600)
        --no-coalesce                Skip Magick::ImageList#coalesce() if input doesn't need it.
        --no-gifsicle                Prevent filter the output through gifsicle. Greatly increases output file size.
    -h, --help                       Show this message
    -v, --verbose                    Verbose output
        --version                    Show version

Installation

The following works with OS X and homebrew:

git clone https://github.com/dergachev/screengif.git
cd screengif

# x-quartz is a dependency for gifsicle, no longer installed starting on 10.8
brew cask install x-quartz 
open /usr/local/Cellar/x-quartz/2.7.4/XQuartz.pkg # runs the XQuartz installer

brew install ffmpeg imagemagick gifsicle
# brew install ghostscript # not sure if this is necessary

Tips

See https://gist.github.com/dergachev/4627207#os-x-screencast-to-animated-gif for a guide on how to use Quicktime Player to record a screencast on OS X.
Keep in mind that other tools (like Screenflow) produce better video quality.

If you install copy-public-url, the following will automatically upload your new gif to Dropbox:

cp out.gif ~/Dropbox/Public/screenshots

Resources

Related solutions

• http://freezeframe.chrisantonellis.com/ (js library to freeze/play gifs)
• http://askubuntu.com/questions/107726/how-to-create-animated-gif-images-of-a-screencast

RMagick

• http://railscasts.com/episodes/374-image-manipulation?view=asciicast

• http://ruby.bastardsbook.com/chapters/image-manipulation/

• https://github.com/markandrus/imgswiss/blob/master/pipeline.rb (ffmpeg -> imagemagick via rmagick -> gif)

• http://www.imagemagick.org/RMagick/doc/info.html#format

• http://www.imagemagick.org/RMagick/doc/draw.html#rectangle

• http://www.imagemagick.org/RMagick/doc/constants.html#GravityType

• http://www.simplesystems.org/RMagick/doc/optequiv.html

• http://www.imagemagick.org/RMagick/doc/ilist.html

• http://www.imagemagick.org/RMagick/doc/clip_path.rb.html (define_clip_path example)

Imagemagick

• http://www.imagemagick.org/Usage/draw/
• http://www.imagemagick.org/Usage/anim_opt/
• http://www.imagemagick.org/Usage/transform/#fx
• http://www.imagemagick.org/Usage/layers/
• http://www.imagemagick.org/script/command-line-options.php#delete
• http://www.imagemagick.org/script/fx.php
• http://www.imagemagick.org/script/escape.php
• http://www.imagemagick.org/Usage/annotating/#watermarking
• http://www.imagemagick.org/Usage/anim_mods/#frame_mod
• http://www.ioncannon.net/linux/81/5-imagemagick-command-line-examples-part-1/

Bash guides

• http://andreinc.net/2011/09/04/bash-scripting-best-practice/
• http://stackoverflow.com/questions/242538/unix-shell-script-find-out-which-directory-the-script-file-resides

Ruby guides

• TODO: implement tests; see https://github.com/pgericson/progress_bar/blob/master/test/arguments_test.rb
• TODO: look at mixlib-{shellout,cli,logger}; https://github.com/opscode/mixlib-shellout
• TODO: look at https://github.com/bitboxer/simple_progressbar/blob/master/lib/simple_progressbar.rb