WMV File Extension

Windows Media Video
File extension: .wmv
MIME type: video/x-ms-wmv
Uniform Type Identifier: com.microsoft.windows-​media-wmv
Developed by: Microsoft
Type of format: video file format

What is OGG file?

File extension: .ogg
MIME type: application/ogg
Magic: OggS
Developed by: Xiph.Org Foundation
Type of format: Container format
Container for: Vorbis, Theora, Speex, FLAC

Ogg is an open standard for a free container format for digital multimedia, unrestricted by software patents and designed for efficient streaming and manipulation. Ogg is maintained by the  Xiph.Org Foundation.

Extract audio from WMV to OGG with Mini-stream Ripper