WMV
From Just Solve the File Format Problem
WMV (Windows Media Video) is a series of closely-related (so much that they can be described as versions of the same codec) proprietary video codecs designed by Microsoft, with one version eventually released as an open standard (known as VC-1) for interoperability with other vendors. When stored as a computer file, it is usually contained within the ASF container format, and given a file extension of .wmv. VC-1 is also used as one of the video formats contained on Blu-ray Discs.
WMV does not inherently contain Digital Rights Management (DRM), but the ASF container format was designed with the possibility of DRM in mind, so some of these files are so encumbered.
