Streaming audio-only conference call to web

Hi. I have a Windows HMP 3.0 application where I use the Audio Conference API to establish a SIP call between two parties.

Now I want to stream the conference call to a monitor (receive only) on a web page.

I am trying to do it with the IP Media API like this:

IPM_MEDIA_INFO mediaInfo;

memset(&mediaInfo, 0, sizeof(IPM_MEDIA_INFO));

mediaInfo.MediaData[0].eMediaType = MEDIATYPE_AUDIO_REMOTE_CODER_INFO;

mediaInfo.MediaData[0].mediaInfo.AudioCoderInfo.eCoderType = CODER_TYPE_G711ULAW64K;

mediaInfo.MediaData[0].mediaInfo.AudioCoderInfo.eFrameSize = CODER_FRAMESIZE_30;

mediaInfo.MediaData[0].mediaInfo.AudioCoderInfo.unFramesPerPkt = 1;

mediaInfo.MediaData[0].mediaInfo.AudioCoderInfo.eVadEnable = CODER_VAD_DISABLE;

mediaInfo.MediaData[0].mediaInfo.AudioCoderInfo.unCoderPayloadType = 0;

mediaInfo.MediaData[0].mediaInfo.AudioCoderInfo.unRedPayloadType = 0;

strncpy_s(mediaInfo.MediaData[0].mediaInfo.PortInfo.cIPAddress, remoteIP.c_str(), IP_ADDR_SIZE);

mediaInfo.MediaData[0].mediaInfo.PortInfo.unPortId = remotePort;

mediaInfo.unCount = 1;

if (ipm_StartMedia(ipm, &mediaInfo, DATA_IP_SENDONLY, EV_ASYNC) == 0) ...

But ipm_StartMedia() returns -1 and I get an "Invalid Parameter" message. In the RTF log I see this:

12/01/2015 17:02:38.613   2656        5752 libipm                  APPL         ipmedialib            ipmB1C3   <:::: ipm_StartMedia(9,0x652E954,0x1,0x8000)
12/01/2015 17:02:38.613   2656        5752 libipm_ipvsc            INTF         Ipmedialib            ipmB1C3    <=== ipm_StartMedia(9,0x652E954,0x1,0x8000)
12/01/2015 17:02:38.613   2656        5752 libipm_ipvsc            INTF         CIPVscChannel         ipmB1C3    <=== ::StartMedia()
12/01/2015 17:02:38.613   2656        5752 libipm_ipvsc            INFO         CIPVscChannel         ipmB1C3    ---  ::DetermineIPVersion 
12/01/2015 17:02:38.613   2656        5752 libipm_ipvsc            INFO         CIPVscChannel         ipmB1C3    ---  ::StartMedia DetermineAudioVideoMode = 0xffff
12/01/2015 17:02:38.613   2656        5752 libipm_ipvsc            INFO         CIPVscChannel         ipmB1C3    ---  ::StartMedia Video IIPVsc::MEDIAMODE = 0xffff
12/01/2015 17:02:38.613   2656        5752 libipm_ipvsc            ERR1         CIPVscChannel         ipmB1C3    ---  ::SetVideoMediaInfo (Unknown MediaType=0x5) ipmB1C3
12/01/2015 17:02:38.615   2656        5752 libipm_ipvsc            EXCE         Ipmedialib            ipmB1C3    ===> ipm_StartMedia(): Exception=CIPMException,Line=3506,File=ipvscchannel.cpp

Why am I getting this SetVideoMediaInfo() error? Am I going around this the wrong way? Thanks.