Decoder dvdsub [DVD subtitles]:
    General capabilities: none
dvdsubdec AVOptions:
  -palette           <string>     .D...S... set the global palette
  -ifo_palette       <string>     .D...S... obtain the global palette from .IFO file
  -forced_subs_only  <boolean>    .D...S... Only show forced subtitles (default false)


