support for dual-layer Dolby Vision in single track from Annex B bitstreams
Reading dual-layer Dolby Vision (with both layers in the same track) from Annex B type bitstreams (elementary streams or from MPEG transport streams) requires parsing the UNSPEC63
NALUs and re-creating the hvcE
HEVCDecoderConfigurationRecord
.
Extracting such a track requires parsing the hvcE
record & re-creating the relevant UNSPEC63
-wrapped NALUs for the parameter sets from the hvcE
record. It also requires normalizing the UNSPEC63
-wrapped NALUs, much like the regular parameter sets are normalized.