Static kVTEncodeFrameOptionKey_ForceLTRRefresh 

pub unsafe static kVTEncodeFrameOptionKey_ForceLTRRefresh: &'static CFString

Available on crate feature VTCompressionProperties only.

Set this option to kCFBooleanTrue to force an LTR refresh

When the encoder receives this request on an incoming frame, the encoder will encode a new reference frame using a previously acknowledged LTR, or it will encode a new IDR if no LTR frames have been acknowledged.

Also see: kVTCompressionPropertyKey_EnableLTR kVTEncodeFrameOptionKey_AcknowledgedLTRTokens kVTSampleAttachmentKey_RequireLTRAcknowledgementToken

See also Apple’s documentation