After reading this blog, Peggi's whitepaper, and the MSDN Documentation, you decided to write a CODEC for an image file type. The CODEC was even tested in WICExplorer. Great! Now you hope that the CODEC is fully functional... meaning that you can use it from the Windows Vista shell, Windows Vista Photo Gallery, and any WPF application that's written. Wouldn't it be simpler to have a tool to check the registry settings and run a set of important tests to assist in the verification?

My team has given some serious thought to this. In order to help facilitate in this task, we've come up with a tool called WICGrinder. To use the tool, you:

  1. create a new script
  2. enter in your CODEC's GUIDs for the container format, decoder, and encoder (if supported)
  3. provide sample images for your CODEC

After this you run the script and a verbose output of your CODEC's capabilities is outputted. Tests that are included are those that specifically check for items pointed out in Peggi's whitepaper. If WICGrinder crashes, you may run it under a debugger with a debug build of your CODEC to determine what caused it to crash. A complete readme is included in the zip download.

In order to run this, you should have the latest Windows Vista build installed (RC1 or greater). If you have any questions about the tool, please email Also, if you have any questions about WIC in general, please email

Download it today: WICGrinder [Update 2006.11.10... please use the updated version: WICGrinder (x86); WICGrinder (x64)]

(Disclaimer: Though WICGrinder covers a variety of tests, running WICGrinder alone is not a replacement for other testing that you should do for your CODEC (comprehensive test coverage, stability, reliability, security, fuzzing, etc). WICGrinder is meant as a supplement to your own testing. Running WICGrinder does not make any guarantees what-so-ever.)