A 603 extension format is a proprietary GANZ video compression file.
It can only be decoded with the GANZ Player and or the GANZ video client associated with the DVR system.
How to open:
Use GANZ video client to playback *.603 files.
How to convert:
As far as we know, this .603 file type can't be converted to any other file format. This is usually the case of system, configuration, temporary, or data files containing data exclusive to only one software and used for its own purposes. Also some proprietary or closed file formats cannot be converted to more common file types in order to protect the intellectual property of the developer, which is for example the case of some DRM-protected multimedia files.