The master code is tested in Windows 10, with the following problems.（test winows10 baresip <-> linux(RPI) baresip）

1. The local audio has no code to spread to the remote.
2. During the meeting, the local cannot hang up normally. (neither remote nor local)

//log
PS D:\baresip\bin_vpn> .\baresip-win32.exe -e "/dial sip:0755000002@10.8.0.2"
baresip v0.6.5 Copyright (C) 2010 - 2020 Alfred E. Heggestad et al.
Binding to interface or IP address '10.8.0.3'
Local network address: IPv4={E6BEA673-6CFE-46B8-A7E8-B6CEB6F98FBB}|10.8.0.3
httpd: listening on 0.0.0.0:8000
aucodec: opus/48000/2
aucodec: PCMU/8000/1
aucodec: PCMA/8000/1
aufilt: speex_pp
winwave: output devices: 1, input devices: 1
ausrc: winwave
auplay: winwave
vidcodec: H264
vidcodec: H264
vidcodec: H263
vidcodec: MP4V-ES
vidcodec: H265
avcodec: using H.264 encoder 'libx264' -- libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
avcodec: using H.264 decoder 'h264' -- H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
avcodec: using H.265 encoder 'libx265' -- libx265 H.265 / HEVC
avcodec: using H.265 decoder 'hevc' -- HEVC (High Efficiency Video Coding)
vidsrc: dshow
vidisp: sdl
medianat: stun
medianat: turn
medianat: ice
medianat: ice-lite
Populated 1 account
glog: module init
Could not create logging file: No such file or directory
Could not create logging file: No such file or directory
Populated 3 contacts
Populated 3 audio codecs
Populated 1 audio filter
Populated 5 video codecs
Populated 0 video filters
baresip is ready.
/dial sip:0755000002@10.8.0.2
ua: using best effort AF: af=AF_INET
call: connecting to 'sip:0755000002@10.8.0.2'..
unhandeled request from 10.8.0.3:5060: REGISTER sip:10.8.0.3
reg: sip:0755000003@10.8.0.3: 501 Not Implemented (baresip v0.6.5 (?/win32))
call: SIP Progress: 180 Ringing (/)
play: /usr/share/baresip/ringback.wav: No such file or directory
stream: incoming rtp for 'audio' established, receiving from 10.8.0.2:18348
audio: Set audio decoder: opus 48000Hz 2ch
audio: player started with sample format S16LE
long async blocking: 240>100 ms (h=0xfc9f00 arg=0x1592e38)
stream: update 'audio'
stream: update 'video'
audio: Set audio encoder: opus 48000Hz 2ch
speex_pp: Speex preprocessor loaded: srate = 48000Hz
audio: source started with sample format S16LE
audio tx pipeline: winwave ---> speex_pp ---> opus
audio rx pipeline: winwave <--- opus
Set video encoder: H264 packetization-mode=0 (2000000 bit/s, 25.00 fps)
avcodec: h264 encoder activated
dshow: got device '' id=0
Set video decoder: H264 packetization-mode=0
avcodec: h264 decoder activated
avcodec: decode: hardware accel disabled
0755000003@10.8.0.3: Call established: sip:0755000002@10.8.0.2
long async blocking: 715>100 ms (h=0xfc9f00 arg=0x1593180)
stream: incoming rtp for 'video' established, receiving from 10.8.0.2:48144
[h264 @ 038e8bc0] no frame!
avcodec: avcodec_send_packet error, packet=26 bytes, ret=-1094995529 (Invalid data found when processing input)
video: H264 decode error (seq=9012, 5 bytes): Unknown error
video: receiving with resolution 352 x 288 and format 'yuv420p'
sdl: created renderer 'direct3d'
long async blocking: 308>100 ms (h=0xfc9f00 arg=0x15a0890)
[libx264 @ 038d6940] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 038d6940] profile Constrained Baseline, level 3.1, 4:2:0, 8-bit
long async blocking: 762>100 ms (h=0xf81760 arg=0x158fcd8).8/22.0
long async blocking: 102>100 ms (h=0xfad4c0 arg=0x15e1ec0).7/22.8
unhandeled request from 10.8.0.3:5060: REGISTER sip:10.8.0.34/21.0
reg: sip:0755000003@10.8.0.3: 501 Not Implemented (baresip v0.6.5 (?/win32))
long async blocking: 108>100 ms (h=0xfad4c0 arg=0x15e1ec0)0.5/22.8
long async blocking: 617>100 ms (h=0xf7b950 arg=(nil))ps=10.0/19.0
long async blocking: 108>100 ms (h=0xf7b950 arg=(nil))ps=10.0/19.0
[0:01:43] audio=0/28390 video=506620/281671 (bit/s) efps=10.0/14.5