Packet Loss Concealment (PLC) not/barely working

[mringwal]

When testing audio broadcast, we got a larger number of lost packets and tried to enable the PLC in this (Android's) LC3 codec. However, it's basically not working.

Did anybody try it's PLC yet?

Given that I had no idea where to file an issue with Android, I figured this could be a reasonable place for discussion, too.

I've created a minimal test application that encodes a sine wave and then drops every 20th packet, decodes it and stores it into a wav file.

The wav file is attached: https://user-images.githubusercontent.com/652934/179232913-e903eae1-3052-4a45-b407-fe3ddb349eb0.mp4

and the the test code is here: https://github.com/bluekitchen/liblc3codec/tree/plc-test

(If you want to add the test code here, please say so and let me know what I need to change from an licensing point of view).

Cheers
Matthias