Send video stream with audio to an RTMP server

You can use Screen Capturing SDK as a directshow filter and control it through the Windows Registry.

Please check these documentation articles: https://cdn.bytescout.com/help/BytescoutScreenCapturingSDK/html/Screen_Capturer_Filter__DirectShow_video_filter_API_.htm and https://cdn.bytescout.com/help/BytescoutScreenCapturingSDK/html/Screen_Capturing_Filter_Registry_Settings.htm

Also, see this sample source code:

https://github.com/bytescout/ByteScout-SDK-SourceCode/tree/master/Screen%20Capturing%20SDK/Registry/Set%20Options