seekMap:
  isSeekable = false
  duration = UNSET TIME
  getPosition(0) = [[timeUs=0, position=0]]
numberOfTracks = 1
track 0:
  total output bytes = 324
  sample count = 1
  format 0:
    sampleMimeType = text/vtt
    subsampleOffsetUs = -958710678845
  sample 0:
    time = 5000155
    flags = 1
    data = length 324, hash C0D159A2
tracksEnded = true
