Browser client no sound/audio when streaming

[Tremoot]

I’m working on the default Third Person template of Unreal Engine 5. The only thing I added was a background audio that starts as soon as the application starts:

Packaging this application (Windows) and starting the application will correctly play the sound. But when I start the signalling server for Pixel Streaming and go the browser I can correctly see the renders (and movements) but I do not hear any audio coming from the browser. Looking at the console of the browser I do not see any errors and see that everything is connected correctly:

I’m starting the PixelStreaming signaling server on port 4080 and starting the application with the following parameters: -AudioMixer -PixelStreamingIP=127.0.0.1 -PixelStreamingPort=8888 -Res=1280x720 -ForceRes

I noticed that there are parameters that can enable/disable audio so the client should be able to receive audio, but I’m kind of lost what to do.

[MWillWallT]

Hi there!

If you’re running the stream purely locally, that is extremely odd.
Can I confirm your audio mixer isn’t silencing the browser page?

[Tremoot]

Thanks for the reply. I got it working with normal audio.

But when I use a custom plugin (3rd party) with a custom class that implements ISubmixListener (cpp) the audio does not get to PixelStreaming:

I suspect that the either the engine is not recognizing this SubmixListener as the default SubmixListener and thus does not send it to the PixelStreaming module. Or that the AudioThread used is not the correct thread which the PixelStreaming is listening on.

Hopefully someone who has more audio knowledge (or pixelstreaming knowledge) can shed some light on this subject.

[MWillWallT]

So regarding Pixel Streaming and how it handles audio, it only listens to the main audio device, e.g. GEngine->GetMainAudioDevice() (found in Engine\Plugins\Media\PixelStreaming\Source\PixelStreaming\Private\AudioSubmixCapturer.cpp)

If your third party plugin is not piping its audio into the main audio device, Pixel Streaming won’t capture it. Unfortunately there isn’t any way around this limitation at this time.