WebRTC mode crackling sound

[spawn451]

I use the Reolink Video Doorbell, when I use the WebRTC stream the sound crackles on the other hand in MSE mode no worries.

Is this normal? My setup is as follows:

  reolink:
    - rtsp://admin:password@192.168.10.51:554/Preview_01_sub
    - ffmpeg:reolink#audio=opus

[AlexxIT]

Show stream info json from go2rtc WebUI when you have "crackling" sound.
Can you recognize speech in that crackling sound? Or it totally broken?

[spawn451]

{
  "producers": [
    {
      "type": "RTSP active producer",
      "url": "rtsp://192.168.10.51/Preview_01_sub/",
      "remote_addr": "192.168.10.51:554",
      "user_agent": "go2rtc/1.3.2",
      "medias": [
        "video, recvonly, H.264 High 5.1",
        "audio, recvonly, MPEG4-GENERIC/16000",
        "audio, sendonly, PCMA/8000"
      ],
      "receivers": [
        "96 H264, bytes=211079, senders=1",
        "97 MPEG4-GENERIC/16000, bytes=47988, senders=1"
      ],
      "recv": 262355
    },
    {
      "type": "RTSP passive producer",
      "url": "rtsp://localhost:8554/17da9f1c85babdeda8625479775390c0",
      "remote_addr": "[::1]:35802",
      "user_agent": "ffmpeg/go2rtc",
      "medias": [
        "audio, recvonly, PCMA/8000"
      ],
      "receivers": [
        "8 PCMA/8000, bytes=47088, senders=1"
      ],
      "recv": 48248
    }
  ],
  "consumers": [
    {
      "type": "RTSP passive consumer",
      "url": "rtsp://localhost:8554/reolink?audio",
      "remote_addr": "[::1]:40354",
      "user_agent": "go2rtc/ffmpeg",
      "medias": [
        "audio, sendonly, ANY"
      ],
      "senders": [
        "96 MPEG4-GENERIC/16000, bytes=47988, receivers=1"
      ],
      "send": 49476
    },
    {
      "type": "WebRTC/WebSocket async passive consumer",
      "remote_addr": "udp4 host 192.168.10.58:52433",
      "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/112.0.0.0 Safari/537.36",
      "medias": [
        "video, sendonly, VP8, RTX, VP9, H264, AV1, RED, ULPFEC, FLEXFEC-03",
        "audio, sendonly, OPUS/48000/2, RED/48000/2, G722/8000, PCMU/8000, PCMA/8000, CN/8000, TELEPHONE-EVENT/48000, TELEPHONE-EVENT/8000"
      ],
      "senders": [
        "96 H264, bytes=211079, receivers=1",
        "8 PCMA/8000, bytes=47088, receivers=1"
      ],
      "send": 262175
    }
  ]
}

Yes, but it sounds metallic

[swbouman]

same issue here. audio is horrible, but I can hear the bird. On my YouTube stream, decoded with ffmpeg I putted a noise cancelling filter on top of the stream. Then the sound is gone.

{
  "producers": [
    {
      "type": "RTSP source",
      "url": "rtsp://192.168.178.61/0",
      "remote_addr": "192.168.178.61:554",
      "user_agent": "go2rtc/1.2.0",
      "medias": [
        "video, sendonly, 96 H264/90000",
        "audio, sendonly, 104 MPEG4-GENERIC/48000"
      ],
      "tracks": [
        "96 H264/90000, sinks=3",
        "104 MPEG4-GENERIC/48000, sinks=3"
      ],
      "recv": 1211461163
    },
    {
      "type": "RTSP source",
      "url": "rtsp://localhost:8554/48cb56f59a21ada0aa5c6aa2e3e42cb1",
      "remote_addr": "127.0.0.1:46366",
      "user_agent": "ffmpeg/go2rtc",
      "medias": [
        "audio, sendonly, 96 OPUS/48000/2"
      ],
      "tracks": [
        "96 OPUS/48000/2, sinks=1"
      ],
      "recv": 1310219
    }
  ],
  "consumers": [
    {
      "type": "RTSP client",
      "url": "rtsp://127.0.0.1:8554/Vogelhuis?video=copy\u0026audio=aac",
      "remote_addr": "127.0.0.1:48332",
      "user_agent": "FFmpeg Frigate/0.12.0-da3e197",
      "medias": [
        "video, recvonly, 96 H264/90000",
        "audio, recvonly, 97 MPEG4-GENERIC/48000"
      ],
      "tracks": [
        "96 H264/90000, sinks=3",
        "97 MPEG4-GENERIC/48000, sinks=3"
      ],
      "send": 1211461163
    },
    {
      "type": "RTSP client",
      "url": "rtsp://192.168.178.7:8554/Vogelhuis",
      "remote_addr": "192.168.178.7:37602",
      "user_agent": "Lavf58.45.100",
      "medias": [
        "video, recvonly, 96 H264/90000",
        "audio, recvonly, 97 MPEG4-GENERIC/48000"
      ],
      "tracks": [
        "96 H264/90000, sinks=3",
        "97 MPEG4-GENERIC/48000, sinks=3"
      ],
      "send": 2642664022
    },
    {
      "type": "RTSP client",
      "url": "rtsp://localhost:8554/Vogelhuis?audio",
      "remote_addr": "127.0.0.1:46356",
      "user_agent": "go2rtc/ffmpeg",
      "medias": [
        "audio, recvonly, 96 MPEG4-GENERIC/48000"
      ],
      "tracks": [
        "96 MPEG4-GENERIC/48000, sinks=3"
      ],
      "send": 1252592
    },
    {
      "type": "WebRTC client",
      "remote_addr": "udp4 prflx 192.168.178.20:49615 related :0",
      "user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.4.1 Safari/605.1.15",
      "send": 63049708
    }
  ]
}

[AlexxIT]

Well. Both you transcoding AAC to PCMA or OPUS for WebRTC.
I think we need to work with the ffmpeg settings. Maybe can find better ones.

[swbouman]

Hey Alexx,

For YouTube I use the following command to reduce noise: -af "afftdn=nr=10:nf=-40:tn=1"

Hope this points in the right direction. I need to transcode the audio, because camera is only producing AAC sound.

btw this is the YouTube link ;) https://www.youtube.com/live/W_GfyJm-gNk?feature=share

[AlexxIT]

Should be fixed https://github.com/AlexxIT/go2rtc/releases/tag/v1.6.0

[spawn451]

Thanks, issue fixed!