MP2 (MPEG Audio Layer 2) is a Moving Picture Experts Group audio format that comes with a .mp2 filename extension. Like MP3, MP2 is a lossy format and is mostly used for sound broadcasting. Because a limited number of audio players support MP2, it’s best to convert it to MP3, which is a universal format.
FLV (Flash Video) is a video container format developed by Adobe Systems and comes with a .flv filename format. FLV is primarily used to stream audio, video, and text data such as subtitles. It supports MPEG-4 Part 10 (H.264) video codec and AAC sound.
RealPlayer, Apple QuicTime Player
VLC Media Player