Weird video: Un-seekable and mkvmerge stucks at 0%
I think I stumbled upon the rarest video stream (or bug) on Earth. Bear with me. I have this BD I remuxed with MKVToolNix v14, months ago. Before remuxing I watched the movie from the BD, everything was fine. I tend to keep my BD collection in MKVs for better portability. So I remuxed the BD and forgot about it (I know that mkvmerge pops up warnings/errors in case of errors in any stream)
I forgot about it till just now. When I open the MKV, if I let it play from the beginning everything looks fine. But as soon as I skip 5 secs forward or backward I get a black screen. The only way to get video again is going to the very start at 0:00:00. If I click the search bar at random points I get the black screen or even get the player to crash. The same happens with MPC-BC.
If I try remuxing the MKV with the current MKVToolNix I get the same results. If I extract the h264 stream with eac3to and then try to mux it in MKVToolNix, it gets stuck at 0% with a 0 byte MKV, not advancing at all. It also starts taking a crazy amount of memory (see image). Almost 6GB of RAM! Really insane and all for nothing.
Back to the original MKV. If I copy everything into a new MKV with ffmpeg ("ffmpeg -i video.mkv -c copy new_video.mkv") and try to play that, I can seek, but the players take several seconds to resume playing after skipping. And after a few skips they crash. Aside from the crash it's weird, since MKV files seek instantly at whatever point you jump ("jump to keyframe" enabled in both players).
I went back to the original MKV and remuxed a minute of it with MKVToolNix. Same black screen as before. BUT, if I then re-remux this little MKV with eac3to or ffmpeg I get a file that, while slow to skip, plays perfectly in both players, not crashing at any time.
I'm really out of options. I've used MKVToolNix since the 4.x.x versions and never had issues. It's the first time I stumbled upon something so weird. I'm guessing that the orignal video stream had something malformed about it that the BD container/structure didn't mind, but it's affecting the MKVs. That or mkvmerge messed up something in the first remux. Honestly, I have no idea.
I'm uploading the 1 min MKV I made from the original to the FTP server.
P.S.: This is very interesting. If I remux the MKV cutting out the first 5 seconds (split based on timestamps, 5s-) the resulting file never shows anything (funnily enough Windows Explorer does show the thumbnail). Upon trying to extract the h264 track with ffmpeg I get a 0KB file. I'm starting to lose my mind as I descend into this madness...