Listen to the experts who know and have better memories.
I had issues with M2T files many years ago and there are, at least, two "fixes".
Fix1: May not work because of the many different implementations of H264 and many other factors. Check the following link and search for ffmpegwrapper. Good luck!
Fix2: Convert the file using HandBrake and then import. (Here are the settings a TechSmith tech, who provided extraordinary help, when I had issues with sound and video being out of synch due to variable rates. Some of the settings are mine so feel free to change any and see if it works. You can adjust and test and remember my opening sentence.)
I am using Handbrake 0.10.2.7286 - 64bit, in case that matters. Only settings I think are important are listed... e.g. Width and Height are not included.
Web Optimized: disabled
iPod SG Support: disabled
Video Codec: H264 (x264)
Framerate (FPS): 30
Constant Framerate: enabled
x264 Preset: Very Fast
x264 Tune: None
Fast Decode: disabled
H.264 Profile: High
H.264 Level: 5.0
Avg bitrate (Kbps): 5000
(note, the 5000 was my setting to match Vimeo and
2-Pass encoding seemed a cheap way to increase
quality without increasing size)
PS. Just found a file with the following information. The above is current but both worked. Sorry, I don't have time to consolidate for you.
Output Settings: Container MP4
Keep Aspect ratio enabled
Video Codec H.264 (x264)
Framerate (FPS:) 30
Constant Framerate enabled
Constant Quality disabled 20 RF
Avg Bitrate (kbps): 5000
2-Pass Encoding enabled
Turbo first pass disabled
x264 Preset very fast
x264 Tune none fast decode disabled
h.264 profile High H.264 level 5.0
Extra options (blank)
Add Track Clear
Source 1 Uknown (MPEG) (2.0 ch)
Codec AAC (avcodec)
Add Track Import Srt Clear
Create chapter markers enabled
chapter number (all this defaults to 1 and name "Chapter 1" upon import.