@type t() :: %ExWebRTC.Media.IVF.Header{
  fourcc: non_neg_integer(),
  header_size: non_neg_integer(),
  height: non_neg_integer(),
  num_frames: non_neg_integer(),
  signature: binary(),
  timebase_denum: non_neg_integer(),
  timebase_num: pos_integer(),
  unused: non_neg_integer(),
  version: non_neg_integer(),
  width: non_neg_integer()
}

IVF Frame Header.

Description of these fields is taken from: https://chromium.googlesource.com/chromium/src/media/+/master/filters/ivf_parser.h

• signature - always "DKIF"
• version - should be 0
• header_size - size of header in bytes
• fourcc - codec FourCC (e.g, 'VP80'). For more information, see https://fourcc.org/codecs.php
• width - width in pixels
• height - height in pixels
• timebase_denum - timebase denumerator
• timebase_num - timebase numerator. For example, if timebase_denum is 30 and timebase_num is 2, the unit of ExWebRTC.Media.IVFFrame's timestamp is 2/30 seconds.
• num_frames - number of frames in a file
• unused - unused