Combine merge concatenate mjpeg dashcam video files into h265 mp4 using ffmpeg

8 times faster (PTS/8), 60 fps output, throw away sound (-an):

ffmpeg -f concat -safe 0 -i <(find /media/user/disk/DCIM/100DSCIM/ -type f | sed 's/^/file /') -filter:v "fps=60,setpts=PTS/8" -c:v libx265 -crf 30 -an drive.mp4

They are combined in alphabetical order, if your dashcam has looped the file counter then you may need to add arguments to "find" to print out the date, then pass through "sort" to sort it by date (in the first column) and then "sed" the date out again before passing through the existing sed.