Multiple files are selected.

One of the files must be named manifest.json and contain the following JSON structure:

[
  {
    "begin": 0.5,
    "end": 3,
    "path": "doc001.ttml"
  },
  {
    "begin": 5,
    "end": null,
    "path": "doc002.ttml"
  }
]
            

begin

Start time (in seconds) of the sample that contains the IMSC file. (Number or a string containing a fraction, e.g. "21/3")

end

End time (in seconds) of the sample that contains the IMSC file. (Number or a string containing a fraction, e.g. "21/3")

path

File name of the IMSC file. (String)

All other files must be IMSC files whose filenames appear in manifest.json.

Multiple files are selected.

The files make up a segmented MP4 file with one track whose codec is stpp.

The filename of the files must contain init and it must be an MP4 initialization segment.

All other files must be MP4 segments corresponding to the initialization segment. When lexically sorted by their filenames, they must be in chronological order.