A co-worker of mine wanted to view a presentation that was emailed to him. It was a video in AVI format. When he tried playing the file in Windows Media Player, he could hear the sound but the video did not play. This often happens when the correct codec for the video is not installed. The only problem was that we didn’t know what codec the file needed.

Luckily I came across a handy utility called qaviinfo. Here’s how you can use this utility to locate the codec that an AVI video file needs to have installed before you can view it.

1. Download qaviinfo.exe and save it to the same folder that your AVI file is located. Mine is at C:\Downloads for this example.

2. Open a DOS command prompt (Start > Run > CMD) and navigate to that folder. Type CD C:\Downloads.

3. The name of the video file in my case is presenta.avi. So I can now type qaviinfo presenta.avi.

4. A list of information about the file will be displayed. In the Codec column you can see what codec is being used. Here it is FMP4.

5. A Google search on FMP4 revealed to me this link. Which then led me to The Codecs where I found a download for a file that included the FMP4 codec.

Sucess! I could then play the file and see the video.

See Also: How do I find which codec is needed to play an AVI file?