A fragmented MP4 (Media Source Extension) contains a series of segments which can be requested individually for browser application.
It consists of : moov [moof mdat]+ [moof mdat] + ...
My test clip is a fragmented mp4 which has the same extension name .mp4 but contains the above elements. It has a sound track at aac format and a video at h.264 format. Unfortunately , LibreELEC can not decode it correctly : only sound comes out of the hdmi port , no video at all. The tv box is an amlogic s912 with 2G ram and 8G emmc. Is there sth. I can try to play it ? If more info. about the clip is needed , please do not hesitate to let me know. Thankyou !