Call start message
In 1-to-1 calls, a caller and a callee can send a limited size of message to each other during the call setup process. This message is called a call start message.
| Supported call type | Supported SDK version |
|---|---|
| 1-to-1 call | All versions |
A call start message is functionally equivalent to "Call Init data" available in PlanetKit 5.0.x or lower. Only the name of the feature has been changed since PlanetKit 5.1.
Sending a call start message
A caller and a callee can send a call start message at a different point in time during the call setup process.
To learn more about the call setup flow, see 1-to-1 call flow.
Caller side
A caller can send a call start message when making a call.
To send a call start message on the caller side, create a CallStartMessage, set the CallStartMessage in a MakeCallParam, and pass the MakeCallParam when calling MakeCall().
PlanetKit::CallStartMessagePtr pCallStartMessage;
pCallStartMessage = PlanetKit::CallStartMessage::Create(L"Call start message from a caller");
PlanetKit::PlanetKitCallPtr pPlanetKitCall;
PlanetKit::MakeCallParamPtr pMakeCallParam = PlanetKit::MakeCallParam::CreateWithAccessToken(
myId, peerId, accessToken
);
pMakeCallParam->SetCallStartMessage(pCallStartMessage);
PlanetKit::PlanetKitManagerPtr pPlanetKitManager = PlanetKit::PlanetKitManager::GetInstance();
PlanetKit::SStartResult sStartResult = pPlanetKitManager->MakeCall(pMakeCallParam, &pPlanetKitCall);
The message is delivered to the callee in the OnVerified callback.
Callee side
A callee can send a call start message when accepting a call.
To send a call start message on the callee side, create a CallStartMessage and pass the CallStartMessage when calling AcceptCall().
PlanetKit::CallStartMessagePtr pCallStartMessage;
pCallStartMessage = PlanetKit::CallStartMessage::Create(L"Call start message from a callee");
// The `pPlanetKitCall` variable is the verified `PlanetKitCall` instance.
pPlanetKitCall->AcceptCall(bPreparation, pCallStartMessage);
The message is delivered to the caller in the OnConnected callback.
Size limitation
The maximum size of a call start message is 200 bytes including the null termination character.
Comparison of a call start message and app server data
A call start message and app server data have the following differences:
| Source and destination | Supported call type | |
|---|---|---|
| Call start message | App client of a caller → App client of a callee App client of a callee → App client of a caller | Only 1-to-1 call |
| App server data | App client of a caller or participant → App server | 1-to-1 call, group call (conference) |
Related API
APIs related to the call start message function are as follows.