Dont pay too much attention to what the file extension says. Its the codec that's used that is important. You will often find that a standard encoding format (codec) has been used, but that a different file extension has been tagged to the files.
Try changing the file extension to see if it plays in a good media player (VLC handles most standards).
E.g. If the recording is SomeMovie.trp , change it to SomeMovie.ts or SomeMovie.mpg to see if a common encoding standard has been used, and your media player can play it.
If its a common standard of encoding, your choices of conversion software are huge.
For example, the .ts files recorded by my dreambox will play in Windoz Media Player if I change the file extension to .mpg (Because the correct codecs are installed).
Most hardware manufacturers are not going to spend the money required to develop their own encoding systems, so they just use standard ones and add a different file extension in weak an attempt to thwart people from converting/copying the files, and try to force them to use their software for viewing recordings.
Some seem to modify the standards just enough to stop all but their own software from being able to handle the files.
