MOD is a format containing MPEG-2 video and AC3 audio. The extension is rarely used, that is why it can be opened only with special programs. Also MOD files can be playback by DVD players. If you want to open it with a standard player, the easiest way is to convert the file to MPG. Usually the format is used by Panasonic and JVC for recording video, the data is saved to a hard disk or SD card.

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.