IDeckLinkAncillaryPacket is always blank.

Hey there.

I am trying to extract SCTE-104 packets from the VANC's feed.
My code is below;
It seems to get SCTE-104 packet (I got the message "Got SCTE-104" and the result of IDeckLinkAncillaryPacket->getBytes is success),
but I cannot get any valuable AncillaryPacket Data.
Is there anything wrong ?

Please help.

Code: Select all

HRESULT    DeckLinkDevice::VideoInputFrameArrived (/* in */ IDeckLinkVideoInputFrame* videoFrame, /* in */ IDeckLinkAudioInputPacket* audioPacket)
{
   AncillaryDataStruct      ancillaryData;

   IDeckLinkVideoFrameAncillaryPackets* frameAncillaryPackets = NULL;
   IDeckLinkAncillaryPacket* ancillaryPacket = NULL;
   HRESULT result = S_OK;
   uint8_t ancillaryPacketData;
   unsigned int* size = 0;
   std::string s = "";
   CString displayMessage = NULL;

   if (videoFrame == NULL)
      return S_OK;

   result = videoFrame->QueryInterface(IID_IDeckLinkVideoFrameAncillaryPackets, (void**)&frameAncillaryPackets);
   if (result != S_OK)
   {
      fprintf(stderr, "Could not get ancillary packet store = %08x\n", result);
      goto bail;
   }

   result = frameAncillaryPackets->GetFirstPacketByID(0x41, 0x7, &ancillaryPacket); // for SCTE-104 packet
   if (result != S_OK) {
      goto bail;
   }
   else {
      MessageBox(NULL, TEXT("Got SCTE-104"), TEXT("title"), MB_OK);
   }
   

   result = ancillaryPacket->GetBytes(bmdAncillaryPacketFormatUInt8, (const void**)&ancillaryPacketData, size);
   if (result != S_OK) {
      MessageBox(NULL, TEXT("Could not get bmdAncillaryPacketFormatUInt8"), TEXT("title"), MB_OK);
      goto bail;
   }
   else {
      // ancillaryPacketData is blank
   }



[Cameron Nichols]

Hi Yuichiro,

I believe there is an issue with the output parameter types you are calling IDeckLinkAncillaryPacket::GetBytes() with.

Can you please retry with the following changes:

Code: Select all

uint8_t* ancillaryPacketData;
unsigned int size = 0;

Code: Select all

result = ancillaryPacket->GetBytes(bmdAncillaryPacketFormatUInt8, (const void**)&ancillaryPacketData, &size);

Also check what the value for "size" is being output.

Regards
Cameron

Hi Cameron,

I could get the right packet data with the changes you mentioned.
Thank you for your quick reply and your kind help.