How in the Tech

Listing the Installed Codecs on your Computer

By Adam Myers ⋅ January 5, 2009 ⋅ Tags: Multimedia

For most of us, we generally don’t care what codecs – the libraries that enable the decoding of audio/video in the files we download -  are installed just so long as the content is displayed correctly. This is true in 99% of my cases as well; I know that opening a video file in the popular media player VLC just works with no muss or fuss. I think everyone can agree that when trying to enjoy some content, the last thing we want to worry about is why said content is not playing. However, there is that other 1% where I need to get my hands dirty.

CoreAVC is billed as the worlds fastest h.264 decoder, some 30% fastest than libavcodec – the free codec that you are likely using, that is if any of this makes sense. CoreAVC is not free however but costs a modest $15, a small price for a codec that can make the difference between smooth 1080p content or a stuttering slideshow. If you’ve committed yourself to the expense, you want to ensure that your media player is using the appropriate codec!

Unsurprisingly, the installed codecs list is stored in the Windows Registry; specifically at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32 and HKEY_CLASSES_ROOT\CLSID\{083863F1-70DE-11d0-BD40-00A0C911CE86}\Instance. However, this isn’t at all convenient or even easy to dissect. That’s where a handy utility from NirSoft comes into play – InstalledCodec. As you can determine from other intelligently named software programs, InstalledCodec organizes the two registry entry lists from above into a nice table layout.

As seen here, the list view provides a fair bit of information – some more useful than others. In my situation, not only can I see that the CoreAVC decoder was installed correctly I can also disable any other h.264 decoders I had installed previously. Now, this is a pretty technical example of a real problem as you’d need to have a deeper understanding of video codecs, as well as the terms AAC, h.264, or AC3 not intimdating you. You may even go as far as removing the codecs entirely, just be sure to keep a backup of the file until you are 100% certain all your media content still plays correctly. I have over 250 codecs installed, most of which not knowingly by me. So, be careful!