alternative to avidemux?

[Victor <victor@svictor.net>]

Hi,
I’m looking for an alternative to avidemux. I need it for two specific 
tasks:

a) cut and remux videos without reencoding (so you can cut a 30min chunk 
in a 3h video without loosing quality)
b) burn in .ass/.ssa subtitles (this is the Substation alpha format, 
where you can do fancier things than with srt)
+ It should have a gui, especially for the (a) task (to locate precisely 
the in/out cutting points).

I used to do this with avidemux when I was on ubuntu and it worked all 
right. But avidemux is not part of the official Debian packages.
It is on deb-multimedia, but I’d prefer not to enable a whole repo just 
for this.
I did compile avidemux successfully in the past, and it worked. But now 
it’s broken probably due to some upgrade I did meanwhile… So before I 
set to recompile it, I was wondering if maybe some other program in 
debian (Jessie) includes the above features.

Thanks for reading! Blue skies,
Victor