OptionalaOptionalchannelChannel layout is a 2.1 only option
OptionalcustomOptional custom parameters that will be appended to any command
OptionalframesOptionalmodeOptionalscaleFFmpeg and image producer scale mode. Since 2.5.0
OptionaltransitionOptionalvFfmpeg video filter, serialized as vfilter in 2.2+ and filter before 2.2
2.2+ only option, specifify a channelLayout for backwards compatibility