Play/Merge multiple audio streams with a single player

[Lizhengbo0304]

I have a video file without audio and I want to pass public DecoderContext.ExternalStreamOpenedArgs Open(ExternalStream extStream,bool resync = true,bool defaultAudio = true,int streamIndex = -1); method adds ExternalAudioStream for synchronous playback. I found that when I added multiple ExternalAudioStreams, the last one always took effect, and there was no expected effect of all AudioStreams playing at the same time. I would like to ask if there is any way to add multiple ExternalAudioStreams at the same time and take effect at the same time