(I copied my post from this thread here as well)
Hi,
we also encounter that issue. It is actually more severe on Win10, because the OS will react on if you have a headphone or speaker plugged in or not. And if not it will disable the Default Audio Device. Which leads to the awkward behavior that you only can start the game if you have a headphone plugged in.
I was looking into the code and it seems the perfect place to check for this would be in WindowsMovieStreamer.cpp
in the function FVideoPlayer::AddStreamToTopology(…)
There is the condition : if (MajorType == MFMediaType_Audio)
Within a static function check like this would be good (like it is done for the HeadMountedDisplay):
if (FUnrealAudioModule::IsDefaultAudioDeviceAvailable() == false)
{
return OutDimensions; // do not add the audio stream because there is no device available
}
But currently there is no IsDefaultAudioDeviceAvailable. I was trying to add one by myself but the problem is that this early in the game there is no GWorld and no GEngine so, no access to the Unreal AudioDevice. To fix that would need some Win-API coding … probably better if Epic would do this 