WebM is an open media container compressed with VP8 video codec and Vorbis audio codec. WebM format has high video playback quality and data compression parameters.The format is widely used for adding media to web pages and it is supported by all modern web-browsers like Opera, Mozilla Firefox and Google Chrome. The embedding of WebM videos to a site page realizes without delays and errors. WebM is meant to be an alternative to the h.264 standard. The copyright of the extension is held by Google.

PVF is a special low-bandwidth ADPCM-based digital audio format for recording and storing human speech. A .pvf file contains digitally recorded speech in the PVF format. Such .pvf files were mainly used with legacy voice modems and software-based answering machines. Often, to be used with a specific modem, a .pvf file would have to be converted into the device-specific RMD format. Currently, PVF audio files can still be played with several major media players as well as converted into other formats (like WAV) with multi-format converter tools.