Converting .rem files to .mp4 format.
Converting BlackBerry Encrypted Data Files directly to MPEG-4 Videos (.rem to .mp4 conversion) is, per se, not possible. You will have to use a workaround.
First, you need to switch off the encryption on the source device, before the files can be accessed and moved to another device.
Based on the actual file type, you will have to find out, whether a conversion to MP4 format is possible.
We are not aware of any software or (online) conversion tool capable of converting REM to MP4.
RIM application used to synchronize of BlackBerry smart phones with PCs