Static kVTEncodeFrameOptionKey_AcknowledgedLTRTokens 

pub unsafe static kVTEncodeFrameOptionKey_AcknowledgedLTRTokens: &'static CFString

Available on crate feature VTCompressionProperties only.

A CFArray of CFNumbers containing the kVTSampleAttachmentKey_RequireLTRAcknowledgementToken values which have been successfully sent to the receiver and can be used as references

When an LTR frame is encoded, the encoder will return a unique token for the LTR frame on the output CMSampleBuffer through kVTSampleAttachmentKey_RequireLTRAcknowledgementToken. This token is then returned to the encoder via kVTEncodeFrameOptionKey_AcknowledgedLTRTokens when the LTR frame is received by the remote consumer(s).

Also see: kVTCompressionPropertyKey_EnableLTR kVTEncodeFrameOptionKey_ForceLTRRefresh kVTSampleAttachmentKey_RequireLTRAcknowledgementToken

See also Apple’s documentation