Issue with GStreamer in gst-meet: "streaming stopped, reason not-linked (-1)" when microphone is enabled

Hello everyone,

I’m using to capture participant video frames in a Jitsi meeting and save them as images. My current pipeline is:[gst-meet](https://github.com/avstack/gst-meet)

GST_DEBUG=*:2,alsa:5 gst-meet --web-socket-url=wss://{domain}}/xmpp-websocket \
         --room-name=8436685a-c17f-4f27-86d7-d1701b07264a \
         --verbose=3 \
         --xmpp-domain=meet.jitsi \
         --recv-pipeline-participant-template="videoconvert name=video ! videorate ! video/x-raw,format=RGB,width=1280,height=720,framerate=1/30 ! queue ! pngenc ! multifilesink location=/screenshot/{nick}_%05d.png"

This works fine when the microphone is muted. However, if a participant enables their microphone, I receive the following error, and the pipeline stops working:

ERROR ../libs/gst/base/gstbasesrc.c(3177): gst_base_src_loop (): /GstPipeline:pipeline0/GstNiceSrc:nicesrc0:
streaming stopped, reason not-linked (-1)

This is logs

2025-03-19T06:56:08.109714Z  WARN ../gst/rtpmanager/gstrtprtxreceive.c(684): gst_rtp_rtx_receive_chain (): /GstPipeline:pipeline0/GstRtpBin:rtpbin/GstBin:bin1/GstRtpRtxReceive:rtprtxreceive0:
Received invalid RTP payload, dropping
2025-03-19T06:56:17.987813Z  INFO Colibri message: EndpointStats { from: Some("0656c67f"), bitrate: Bitrates { audio: Bitrate { upload: 14, download: 0 }, video: Bitrate { upload: 2077, download: 0 }, total: Bitrate { upload: 2091, download: 0 } }, packet_loss: PacketLoss { total: 0, download: 0, upload: 0 }, connection_quality: 95.045456, jvb_rtt: Some(8), server_region: None, max_enabled_resolution: Some(720) }
0:00:50.403024164 65344 0x7fa8e8003520 WARN              rtpsession rtpsession.c:3811:session_nack: Removing 1 expired NACKS
0:00:50.438170597 65344 0x7fa8e8003520 WARN              rtpsession rtpsession.c:3811:session_nack: Removing 2 expired NACKS
0:00:50.492039554 65344 0x7fa8e8003520 WARN              rtpsession rtpsession.c:3811:session_nack: Removing 1 expired NACKS
0:00:50.543402530 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.548135533 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.548445845 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.550525682 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.557993733 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.564694509 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.564852110 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.570110683 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
0:00:50.575309062 65344 0x7fa8e8003d20 WARN         rtpjitterbuffer rtpjitterbuffer.c:771:rtp_jitter_buffer_calculate_pts: backward timestamps: ignore rtx packet
2025-03-19T06:56:27.994822Z  INFO Colibri message: EndpointStats { from: Some("0656c67f"), bitrate: Bitrates { audio: Bitrate { upload: 14, download: 0 }, video: Bitrate { upload: 2006, download: 0 }, total: Bitrate { upload: 2020, download: 0 } }, packet_loss: PacketLoss { total: 0, download: 0, upload: 0 }, connection_quality: 91.818184, jvb_rtt: Some(139), server_region: None, max_enabled_resolution: Some(720) }
0:00:57.753955928 65344 0x7fa8e8003520 WARN            rtpssrcdemux gstrtpssrcdemux.c:585:gst_rtp_ssrc_demux_clear_ssrc:<rtpssrcdemux0> unknown SSRC 6b8683c8
2025-03-19T06:56:38.003583Z  INFO Colibri message: EndpointStats { from: Some("0656c67f"), bitrate: Bitrates { audio: Bitrate { upload: 14, download: 0 }, video: Bitrate { upload: 1532, download: 0 }, total: Bitrate { upload: 1546, download: 0 } }, packet_loss: PacketLoss { total: 0, download: 0, upload: 0 }, connection_quality: 70.27273, jvb_rtt: Some(10), server_region: None, max_enabled_resolution: Some(720) }
2025-03-19T06:56:47.017084Z  INFO Colibri message: EndpointStats { from: Some("0656c67f"), bitrate: Bitrates { audio: Bitrate { upload: 14, download: 0 }, video: Bitrate { upload: 1963, download: 0 }, total: Bitrate { upload: 1977, download: 0 } }, packet_loss: PacketLoss { total: 0, download: 0, upload: 0 }, connection_quality: 88.32873, jvb_rtt: Some(10), server_region: None, max_enabled_resolution: Some(720) }
0:01:12.745828412 65344 0x7fa8e8003d20 WARN                 basesrc gstbasesrc.c:3127:gst_base_src_loop:<nicesrc0> error: Internal data stream error.
0:01:12.747231660 65344 0x7fa8e8003d20 WARN                 basesrc gstbasesrc.c:3127:gst_base_src_loop:<nicesrc0> error: streaming stopped, reason not-linked (-1)
2025-03-19T06:56:48.119550Z ERROR ../libs/gst/base/gstbasesrc.c(3127): gst_base_src_loop (): /GstPipeline:pipeline0/GstNiceSrc:nicesrc0:
streaming stopped, reason not-linked (-1)
2025-03-19T06:56:56.441666Z  INFO Colibri message: EndpointConnectivityStatusChangeEvent { endpoint: "6d6036f7", active: false }
2025-03-19T06:56:57.991927Z  INFO Colibri message: EndpointStats { from: Some("0656c67f"), bitrate: Bitrates { audio: Bitrate { upload: 29, download: 0 }, video: Bitrate { upload: 1902, download: 0 }, total: Bitrate { upload: 1931, download: 0 } }, packet_loss: PacketLoss { total: 0, download: 0, upload: 0 }, connection_quality: 87.77273, jvb_rtt: Some(5), server_region: None, max_enabled_resolution: Some(720) }
2025-03-19T06:57:07.988027Z  INFO Colibri message: EndpointStats { from: Some("0656c67f"), bitrate: Bitrates { audio: Bitrate { upload: 31, download: 0 }, video: Bitrate { upload: 1437, download: 0 }, total: Bitrate { upload: 1468, download: 0 } }, packet_loss: PacketLoss { total: 0, download: 0, upload: 0 }, connection_quality: 66.72727, jvb_rtt: Some(7), server_region: None, max_enabled_resolution: Some(720) }
0:01:40.914119029 65344 0x7fa8e8003520 WARN            rtpssrcdemux gstrtpssrcdemux.c:585:gst_rtp_ssrc_demux_clear_ssrc:<rtpssrcdemux0> unknown SSRC aec9c5

If I disable the microphone and only enable the camera, the pipeline works fine. I just learned about gstream so I still lack understanding. I hope everyone can help.