From time to time I convert videos but in some cases, I only need to Cat the file into the new format if the audio and video codec are supported. An example MKV file with Mpeg video and AAC audio.
I can simply do: cat file.mkv > file.mp4
There is where been able to see the metadata from the file manager is useful and I often need to check the details tab on files but this feature is not implemented in Caja. If you also want this to be implemented consider adding yourself to this bug at launchpad
Gnome2 used to have media info as a tab in Properties supplied from the totem media player. I don’t think Caja ever had this integration so it’s been gone ever since. I still miss it a little when I have to open VLC just to Ctrl+I for such detailed info these days.