How to create a webrtc peer connection in an offline only mode. There is no access to the internet

[natealcedo]

Question

How do I create a webrtc peer connection? I've gone through the documentation but there isn't any part on how the peer connection offer is created, accepted and peer connections setup. From the documentation, it's not clear if I am supposed to do a POST localhost:8889/mystream, do a web socket message etc. Is it by a REST API call? A websocket message? etc

[aler9]

If you mean "how to read a MediaMTX stream through WebRTC and a custom web-based client" (i'm assuming since you didn't provide any context), the README suggests to take a look at the read page which also contains a ready-to-use JavaScript class.

If the programming language or context is different, here we are using the WHEP standard to exchange SDPs that allow to establish a peer connection.

[natealcedo]

I apologise, I didn't provide more context. My use case is that everything is offline. There is no internet access. When I try to create a peer connection, it succeeds as per the logs of the mediamtx but no video or audio is being output on the client device.

Further more, after some time, the connection just times out. This doesn't happen when the mediamtx server is connected to the internet. Only when there is no access to the internet.

Here are the logs I received when doing so. Notice that I'm not doing anything actively yet the peer connection is established but eventually closes. Hope this gives more clarity

[libx264 @ 0x14c99a9e0] using cpu capabilities: ARMv8 NEON
[libx264 @ 0x14c99a9e0] profile High 4:2:2, level 3.1, 4:2:2, 8-bit
[libx264 @ 0x14c99a9e0] 264 - core 164 r3108 31e19f9 - H.264/MPEG-4 AVC codec - Copyleft 2003-2023 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=21 lookahead_threads=3 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=0
2025/01/31 23:07:06 INF [RTSP] [conn [::1]:54087] opened
2025/01/31 23:07:06 INF [RTSP] [session ab7bebf6] created by [::1]:54087
2025/01/31 23:07:06 INF [RTSP] [session ab7bebf6] is publishing to path 'mywebcam', 2 tracks (H264, MPEG-4 Audio)
Output #0, rtsp, to 'rtsp://localhost:8554/mywebcam':
  Metadata:
    encoder         : Lavf60.16.100
  Stream #0:0: Video: h264, yuv422p(tv, progressive), 1280x720, q=2-31, 30 fps, 90k tbn
    Metadata:
      encoder         : Lavc60.31.102 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
  Stream #0:1: Audio: aac (LC), 48000 Hz, mono, fltp, 69 kb/s
    Metadata:
      encoder         : Lavc60.31.102 aac
2025/01/31 23:07:09 INF [WebRTC] [session 841ef76f] created by 192.168.2.13:59033
2025/01/31 23:07:09 INF [WebRTC] [session 1b95efc8] created by 192.168.2.13:59034
2025/01/31 23:07:09 WAR [WebRTC] [session 1b95efc8] skipping track 2 (MPEG-4 Audio)
2025/01/31 23:07:09 WAR [WebRTC] [session 841ef76f] skipping track 2 (MPEG-4 Audio)
2025/01/31 23:07:09 INF [WebRTC] [session 841ef76f] peer connection established, local candidate: host/udp/127.0.0.1/8189, remote candidate: prflx/udp/192.168.0.26/54664
2025/01/31 23:07:09 INF [WebRTC] [session 841ef76f] is reading from path 'mywebcam', 1 track (H264)
2025/01/31 23:07:09 INF [WebRTC] [session 1b95efc8] peer connection established, local candidate: host/udp/127.0.0.1/8189, remote candidate: prflx/udp/192.168.0.26/63829
2025/01/31 23:07:09 INF [WebRTC] [session 1b95efc8] is reading from path 'mywebcam', 1 track (H264)
2025/01/31 23:07:38 INF [WebRTC] [session 1a9df512] created by 192.168.2.13:59049
2025/01/31 23:07:38 WAR [WebRTC] [session 1a9df512] skipping track 2 (MPEG-4 Audio)
2025/01/31 23:07:38 INF [WebRTC] [session 20b70307] created by 192.168.2.13:59050
2025/01/31 23:07:38 WAR [WebRTC] [session 20b70307] skipping track 2 (MPEG-4 Audio)
2025/01/31 23:07:38 INF [WebRTC] [session 20b70307] peer connection established, local candidate: host/udp/127.0.0.1/8189, remote candidate: prflx/udp/192.168.0.26/60354
2025/01/31 23:07:38 INF [WebRTC] [session 20b70307] is reading from path 'mywebcam', 1 track (H264)
2025/01/31 23:07:39 INF [WebRTC] [session 1a9df512] peer connection established, local candidate: host/udp/0.0.0.0/8189, remote candidate: prflx/udp/192.168.0.26/59928
2025/01/31 23:07:39 INF [WebRTC] [session 1a9df512] is reading from path 'mywebcam', 1 track (H264)
2025/01/31 23:08:09 INF [WebRTC] [session 841ef76f] closed: peer connection closed
2025/01/31 23:08:09 INF [WebRTC] [session 1b95efc8] closed: peer connection closed
2025/01/31 23:13:27 INF [WebRTC] [session 20b70307] closed: peer connection closedd=   1x
2025/01/31 23:13:27 INF [WebRTC] [session 1a9df512] closed: peer connection closed
frame=15393 fps= 30 q=20.0 size=N/A time=00:08:33.84 bitrate=N/A dup=5 drop=0 speed=   1x