The Ancillary Data Classes allow client software to easily encode or decode Ancillary Data to or from host buffers in a manner that is compatible with the ways in which NTV2 devices transmit and/or receive ancillary data. See Ancillary Data for more information.

Prior to SDK 15.0, these classes were compiled into their own libajaanc library. Starting with SDK 15.0, they were merged into the libajantv2 library.

Demonstration Applications

Transmit/Playout:

To encode an AJAAncillaryList of AJAAncillaryData packets into other buffer destinations:

Make an AJAAncillaryData object for each packet to be transmitted, and call AJAAncillaryList::AddAncillaryData to add it to the list.
The list will automatically be sorted by ascending location in its Get…TransmitData calls.
For encoding into a “tall” or “taller” VANC frame buffer, call AJAAncillaryList::GetVANCTransmitData.
For devices with Anc extractors (see NTV2DeviceCanDoCustomAnc), to fill the buffers used in the AUTOCIRCULATE_TRANSFER::SetAncBuffers or CNTV2Card::DMAWriteAnc functions, call AJAAncillaryList::GetTransmitData (see SDI Anc Buffer Data Format). For IP S2110 devices, the anc buffer will automatically be transformed into RTP (see RTP Anc Buffer Data Format) in CNTV2Card::AutoCirculateTransfer (or CNTV2Card::DMAWriteAnc) before the actual transfer takes place.

Receive/Capture:

To decode received host ancillary data buffer(s) into an AJAAncillaryList of AJAAncillaryData packets:

For decoding VANC lines from a “tall” or “taller” frame buffer, call the AJAAncillaryList::SetFromVANCData class method, passing it an NTV2Buffer that references the frame buffer (or just the VANC portion of one), and an NTV2FormatDescriptor that describes the raster.
For devices with Anc extractors (see NTV2DeviceCanDoCustomAnc), using the buffer(s) passed to AUTOCIRCULATE_TRANSFER::SetAncBuffers or CNTV2Card::DMAReadAnc, call AJAAncillaryList::SetFromDeviceAncBuffers. For IP S2110 devices (see NTV2DeviceCanDo2110), after the transfer of RTP packet(s) (see RTP Anc Buffer Data Format ) to the host is complete (during the call to CNTV2Card::AutoCirculateTransfer or CNTV2Card::DMAWriteAnc), the host anc buffer’s contents will automatically be transformed into the AJA standard SDI Anc Buffer Data Format .

Principal Classes:

AJAAncillaryData: Container that holds a single Anc packet (or raster line containing “analog” waveform data).
- AJAAncillaryData_Cea608: A CEA-608 data packet.
  - AJAAncillaryData_Cea608_Line21: An “analog” CEA-608 data packet (decoded from or encoded to line 21).
  - AJAAncillaryData_Cea608_Vanc: A CEA-608 data packet sourced from or destined to a “tall” (or “taller”) frame buffer that contains VANC lines.
- AJAAncillaryData_Cea708: Container that holds a single CEA-708 SMPTE 334 packet.
- AJAAncillaryData_Timecode: Container that holds a single timecode packet.
  - AJAAncillaryData_Timecode_ATC: An “analog” (ATC) timecode packet.
  - AJAAncillaryData_Timecode_VITC: A VITC timecode packet.
- AJAAncillaryData_FrameStatusInfo524D: A “524D” frame status info packet.
- AJAAncillaryData_FrameStatusInfo5251: A “5251” frame status info packet.
AJAAncillaryDataFactory: Provides AJAAncillaryDataFactory::Create and AJAAncillaryDataFactory::GuessAncillaryDataType class methods.
AJAAncillaryList: An ordered collection of AJAAncillaryData packets.

Note: Avoid deriving subclasses from AJA-provided classes. AJA recommends using aggregation techniques to incorporate NTV2 functionality into your own classes.