Hi there, karuphee. I too am a Linux user. I too have dealt with the madness behind these browser plugins (often leveraging the 'wonders' of activex) required for these CCTV cameras. Unfortunately, while the rest of the world is getting smart and getting away from browser plugins, the CCTV world... is not. So here are a couple thoughts:
A) For
managing cameras (set up, config changes, etc), it's just easiest to salvage an old computer, throw Windows on it, and have at it. Another alternative is to install Windows in a virtual machine. It goes against what I believe, but what can you do. I personally have Windows 8 on an old laptop that I use just for these things.
B) If your goal is just to have the easiest, smoothest method to simply view the live feed, it's totally do-able if you leverage something like VLC. I actually copied and edited the vlc.desktop launcher file to better accommodate something I was after. I wanted to click an icon, boom, live feed. It went something like this...
1) Copy /usr/share/applications/vlc.desktop to /usr/local/share/applications/rear-cam.desktop (or whatever the name would be for the camera)
2) Edit /usr/local/share/applications/rear-cam.desktop, particularly the exec line, to automatically pass in the RTSP URL as part of the opening sequence.
i.e.: Exec=/usr/bin/vlc --qt-minimal-view --no-video-title-show rtsp://user

assword@192.168.1.20:554/live1.sdp
(the minimal-view and no-vide-title-show entries were to slim things down a bit and give me *just* the feed without anything else)
3) Edit the same file to change the "name" field of the application, etc. This will show you VLC Media Player + Rear Camera in your applications menu, thereby keeping them separated by name.
4) Optional (but I was a big fan of this): I created an icon, added it to /usr/share/icons, and changed the icon path in the config file to reflect that. This way I didn't have the orange VLC cone as the icon for both VLC *and* Rear Camera, but instead, just the orange cone for VLC, and a totally different icon for the Rear Camera stream. I simply found an icon on Google images to leverage.
Something like this. Keep in mind I was aiming for an icon that had square dimensions (same height and width) for consistency.
5) Log out, back in, and you should have this new "application" in your menu. Click it, and it opens to your live stream.
Here's my old full blown rear-cam.desktop for a reference:
http://paste.ubuntu.com/16210815/
In short... I found an icon on Google, saved it, copied the VLC application launcher, edited the icon path to use the icon I just saved, edited the name and exec path to reflect the name of the camera + RTSP stream of my camera, logged out and back in and... win. One click launch direct to my camera stream.
By doing this, you're still fully relying on VLC. You're still using the guts of the VLC desktop (application) file. All it's doing is assigning the newfound "application" a cute little icon while eliminating the otherwise manual steps of opening VLC, opening a network stream, and plugging in the network stream to connect directly to that camera's live stream.
I no longer utilize these files (I had one for each camera) as I ultimately went for an NVR solution on my Ubuntu server which comes with its own cross platform client, *but* this worked out very well for what my intended uses/needs were at the time. If this is something you're after and it helps, great. If not, maybe someday will dig this up on a Google search someday. If nothing else, it's just a thought I was compelled to share.
