Some files are decoded very slowly, video is not smooth,
I compared formats and found out:
Stream #0:00x1: Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p(tv, bt709/bt709/unknown), 5400x2700 [SAR 1:1 DAR 2:1], 94510 kb/s, 59.94 fps, 59.94 tbr, 60k tbn (default)
I tried to recode them to:
ffmpeg -c:v libx265
or:
ffmpeg -c:v libx264
in both cases result is OK, so only this one format is problematic.