The file extension M2P identifies so-called MPEG-2 Program Stream files. These are video files in lossy compression MPEG-2. Program Stream means that the file can contain multiple streams, usually one video and one or more audio streams.
In principle, most video players and editing programs should be able to handle M2P files. If the extension M2P is not recognized or it does not appear in the file selection, changing the extension to mp2 or mpg can help.