I use this library to connect to Freeswitch. During the call process, the dual voice is clear, but the recording of the called person is not clear. The called person is a normal mobile terminal. I use the PortSip open-source app to call, and the recording is fine

[pzhu1015]

[ChenGuoqing1001]

I also encountered the same problem. The quality of the recording files on the linphone client was normal, but when using this library, the quality of the recording files was poor.