Video file editor?
What's the most capable one you know of?
I offloaded my DVR hard disk's recordings, and 90% of them play in Media Player Classic, including premium channel recordings. Still there's about 200 that will not play in ANY media players, of the 2 dozen or so that I've tried. So I want to break them down in an editor program, to see if it's a codec issue, corruption, decryption, or other issue...
Avidemux is one of the more capable GUI editors.
Avidemux - Main Page
However, if you want to look at the codecs, I would use mediainfo.
Also, if you try and open one of the problem files with mplayer from the terminal, the error messages can be helpful.