Muxer matroska [Matroska]:
    Common extensions: mkv.
    Mime type: video/x-matroska.
    Default video codec: mpeg4.
    Default audio codec: vorbis.
    Default subtitle codec: ass.
matroska muxer AVOptions:
  -reserve_index_space <int>        E......... Reserve a given amount of space (in bytes) at the beginning of the file for the index (cues). (from 0 to INT_MAX) (default 0)
  -cluster_size_limit <int>        E......... Store at most the provided amount of bytes in a cluster.  (from -1 to INT_MAX) (default -1)
  -cluster_time_limit <int64>      E......... Store at most the provided number of milliseconds in a cluster. (from -1 to I64_MAX) (default -1)
  -dash              <boolean>    E......... Create a WebM file conforming to WebM DASH specification (default false)
  -dash_track_number <int>        E......... Track number for the DASH stream (from 1 to INT_MAX) (default 1)
  -live              <boolean>    E......... Write files assuming it is a live stream. (default false)
  -allow_raw_vfw     <boolean>    E......... allow RAW VFW mode (default false)
  -flipped_raw_rgb   <boolean>    E......... Raw RGB bitmaps in VFW mode are stored bottom-up (default false)
  -write_crc32       <boolean>    E......... write a CRC32 element inside every Level 1 element (default true)
  -default_mode      <int>        E......... Controls how a track's FlagDefault is inferred (from 0 to 2) (default infer)
     infer           0            E......... For each track type, mark the first track of disposition default as default; if none exists, mark the first track as default.
     infer_no_subs   1            E......... For each track type, mark the first track of disposition default as default; for audio and video: if none exists, mark the first track as default.
     passthrough     2            E......... Use the disposition flag as-is


