OK, I mailed the question, adding:
What type of file is that? Why do not you consider to use non-proprietary file types?
The fact that I have remote access to my files is useless if I have to install NVR Reader to read the files: It only works on PCs and I may not be able to download and install something on every computer I may use to access files remotely on holidays, at work...
And moreover, why was that not documented anywhere? I counted on that remote access feature to limit the inconvenience of being able only to access and playback from IE-capable computers, in 2015.
Best regards,
JA