Here are the classes, structs, unions and interfaces with brief descriptions:

Nasdk
Cframe_t	A decoded video or photo frame, delivered by FrameFunc
Cvideo_options_t	Encoder settings in effect on the sending client, delivered by VideoOptionsFunc
Cvideo_mode_t	What the sending client is currently doing, delivered by VideoModeFunc
Caudio_options_t	Audio encoder settings, see sdk_t::SetAudioOptions and sdk_t::AudioOptions
Caudio_frame_t	Decoded room audio, delivered by DecodedAudioFrameFunc
Cposition_klv_values_t	Platform and sensor position decoded from MISB ST 0601 KLV
Cposition_nmea_values_t	Position decoded from an NMEA 0183 GNSS receiver
Cposition_values_t	Position reported by the sending client, delivered by PositionValuesFunc
Cbandwidth_statistics_t	Full set of transport counters for one reporting period
Cbandwidth_statistics_simple_t	Throughput of the active connection, delivered by BandwidthStatisticsFunc
Ccertificate_t	A server certificate, as filled in by sdk_t::RequestCertificate
Csdk_t	SDK Core