A file can be turned into fragmented MP4 for serving in HLS/DASH, but is it possible to recreate the single file from the segments?
I generated the fragmented MP4 using the HLX muxer from ffmpeg and then I tried putting it back together with concat from ffmpeg using the following command:
ffmpeg -f concat -i init.mp4 file1.m4s file2.m4s file3.m4s -c copy output.mp4
But it outputs this error:
[concat @ 0x7fd995804c80] Line 4: unknown keyword '?ftypiso5'
init.mp4: Invalid data found when processing input