R&D audio streaming

[DJ2LS]

some testing with streaming audio.

This is a research and development PR for gathering experience with audio streaming. There is no release date. however, it can probably be improved until production readiness.

Things to find out:

• Best practise for streaming audio to gui and back
• Best parameters for audio buffering in terms of stability and delay
• Test if codec2/rade mode implementation is making sense
• Useful feature implementation

[DJ2LS]

Audio streaming via tcp is problematic.
For LTE connections we need big chunks, like 2400bytes for example.

For fast network / wifi we could reduce down to 300bytes

[DJ2LS]

fastapi/fastapi#960

Problem is TCP/IP which causes problems on slow connections