Recording & compressing short screencasts on Windows

Tools I use

• CamStudio with the lossless codec for screen recording
• ffmpeg
• a scripting environment with shell access (I chose node.js) for batch converting

My process

1. Capture video using Camstudio

   I choose to record 1 window as my region, and compress with the Camstudio lossless codec.

2. Use ffmpeg via a node.js script to batch convert videos

   This turns them into something that can be played in a web browser

   var fs = require("fs"),
     util = require("util"),
     child_process = require("child_process");
   
   var shellCommand =
     "c:\\ffmpeg\\bin\\ffmpeg.exe -i %s -codec:v libx264 -profile:v high -preset slow -b:v 500k -maxrate 500k -bufsize 1000k -threads 0 -y %s";
   
   fs.readdir("./", function (err, paths) {
     paths.forEach(function (path) {
       // TODO - only convert *.avi files
   
       var command = util.format(shellCommand, path, path.replace(".avi", ".mp4"));
   
       var child = child_process.exec(command, function (error, stdout, stderr) {
         console.log(path, err, stdout, stderr);
       });
     });
   });
   

   I base my settings on Jemej’s ffmpeg tutorial. The quality and framerate are low since I usually record things that don’t move much like terminal windows.

Ideas for improving

• this is dumb – it runs every .avi file in the folder through ffmpeg whether it needs or not.
• are there smarter ways to use all the cores of my CPU?
• what about watching for .avi file changes/additions with gaze and encoding new .avi files as soon as CamStudio saves them?