I'm using mediafilesegmenter with input as a fragmented mp4 hvc1 file and got this error:
Nov 23 2023 17:48:25.948: Fragmented MP4 is the only supported container format for the segmentation of HEVC content
Nov 23 2023 17:48:25.948: Unsupported media type 'hvc1' in track 0
Nov 23 2023 17:48:25.948: Unable to find any valid tracks to segment.
Segmenting failed (-12780).