1: The SDK tries to relay the media stream to the destination channel.
3: A failure occurs. See the details in code.
0: The initial state. After you successfully stop the channel media relay by calling \ref IRtcEngine::stopChannelMediaRelay "stopChannelMediaRelay", the \ref IRtcEngineEventHandler::onChannelMediaRelayStateChanged "onChannelMediaRelayStateChanged" callback returns this state.
2: The SDK successfully relays the media stream to the destination channel.
The state code.