Turning Screencasts into Animated .gifs

Sometimes I want to show my screencasts, but the site I want to showcase them doesn’t accept the .mov format that my screencast outputs. A good example is GitHub.

Now, it comes in handy to be able to turn .mov files into animated .gifs

Requirements:

• palettegen
• ffmpeg

The shell file makegif.sh or whatever you want to name it:

#!/bin/bash
cd $PWD
mkdir -p ./gifs
for file in *
  do
    if [[ $file =~ ^(.*)\.mov$ ]]; then
      newfile=${file/.mov/.gif}
      echo Transforming $file ...
      ffmpeg -i $file -vf palettegen temp_palette.png
      ffmpeg -i $file -i temp_palette.png -filter_complex "fps=10,scale=1280:-1[x];[x][1:v]paletteuse" ./gifs/$newfile
      rm -f temp_palette.png
    fi
  done

The above shell script needs to be in the same folder as the .mov files that you want to make into animated .gif files.

The script creates a new directory gifs/, which contain the newly created animated .gif files.

The crux of this is handled by ffmpeg which is a powerful library for dealing with movie file encodings.

A problem we face with converting the .mov file into a .gif is colours. .gif files only support 256 colours, while .mov files have a lot more colours. Fortunately, for screencasts, but all colours are used, so we can create a palette of most comment colours that are used. And we do this with pallettegen. This palette is fed into ffmpeg to construct our .gif in almost exact replication to the .mov file.

Update

In the above shell script, I had to move the files into a speific folder and then run this command. It got extremely cumbersome to have move files around in order to turn them into gifs. I also wanted the option of using a command line tool to turn a selected file into a gif. For examples makegif test.mov.

Hence, I started working on makegif. I decided to use Golang because it’s easy to delivery a binary to work as a CLI (command line interface). It’s essentially glues together multiple projects:

• Cobra - helps create CLIs
• ffmpeg-go - a wrapper for ffmpeg and palletegen

The package can be installed if the user has Golang installed.

go install github.com/shivan-s/makegif

Now it can be used as a normal CLI tool. The plan in future is to make this installable via brew.