I have been coverting MP4s to MPG2s so far and its been ok.
But how do I get Impress to take other formats? (At present it wont import mp4s)
thanks,
It depends on what platform you have LibreOffice installed (Windows, GNU/Linux…) and what codecs you have installed.
You can see the formats supported by your Impress going to Insert > Audio or Video... and opening the File type: dropdown box.
Take into account that those formats (e.g. MP4) are only containers, you must have installed also the codecs used in the audio & video streams within the container.
More info in this link.