Good audio on MSE but choppy audio on WebRTC

[felipecrs]

Hi,

I installed go2rtc (the add-on) for my brother, and he has an old Hikvision DVR. I was able to import his 16 cameras just fine to go2rtc, but audio isn't working very well.

See (and listen) to this demo:

chrome_xWpi1GWgqG.mp4

Basically the audio is very good on MSE, but very bad on WebRTC.

webrtc:
  listen: ":8555"

streams:
    camera_01:
      - rtsp://admin:pass@192.168.1.20/Streaming/Channels/101

{
  "producers": [
    {
      "type": "RTSP active producer",
      "url": "rtsp://192.168.1.20:554/Streaming/Channels/101",
      "remote_addr": "192.168.1.20:554",
      "user_agent": "go2rtc/1.5.0",
      "medias": [
        "video, recvonly, H.264 High 3.1",
        "audio, recvonly, PCMU/8000"
      ],
      "receivers": [
        "96 H264, bytes=1709551, senders=1",
        "0 PCMU/8000, bytes=158720, senders=1"
      ],
      "recv": 1880676
    }
  ],
  "consumers": [
    {
      "type": "WebRTC/WebSocket async passive consumer",
      "remote_addr": "udp4 srflx 179.106.189.52:57785 related 0.0.0.0:0",
      "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 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, L16"
      ],
      "senders": [
        "102 H264, bytes=442838, receivers=1",
        "0 PCMU/8000, bytes=45440, receivers=1"
      ],
      "send": 495741
    }
  ]
}

There are no errors in the logs. Let me know if I should increase some specific logs.

[felipecrs]

PS: Running on a Raspberry Pi 3b+

[NickM-27]

maybe try different audio codecs from the DVR if it's supported?

[felipecrs]

I had looked into it already... the DVR doesn't support changing audio codecs apparently.

[felipecrs]

When consuming with MSE:

{
  "producers": [
    {
      "type": "RTSP active producer",
      "url": "rtsp://192.168.1.20:554/Streaming/Channels/101",
      "remote_addr": "192.168.1.20:554",
      "user_agent": "go2rtc/1.5.0",
      "medias": [
        "video, recvonly, H.264 High 3.1",
        "audio, recvonly, PCMU/8000"
      ],
      "receivers": [
        "96 H264, bytes=250612, senders=1",
        "0 PCMU/8000, bytes=21120, senders=1"
      ],
      "recv": 273420
    }
  ],
  "consumers": [
    {
      "type": "MP4 passive consumer",
      "remote_addr": "179.106.189.52, 172.30.33.2, 172.30.32.1, 172.30.32.2:52518",
      "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 Safari/537.36",
      "medias": [
        "video, sendonly, H264, H265",
        "audio, sendonly, MPEG4-GENERIC, PCMA, PCMU, L16, OPUS"
      ],
      "senders": [
        "96 H264, bytes=250612, receivers=1",
        "0 FLAC/8000, bytes=21120, receivers=1"
      ],
      "send": 304412
    }
  ]
}

[felipecrs]

Oh, by the way I also tried:

streams:
    camera_01:
      - ffmpeg:rtsp://admin:pass@192.168.1.20/Streaming/Channels/101#video=copy#audio=opus

But the exact same problem happened (MSE works, WebRTC is choppy).

{
  "producers": [
    {
      "type": "RTSP passive producer",
      "url": "rtsp://127.0.0.1:8554/5321da5826e23a276a3ebfaeab79d0c3",
      "remote_addr": "127.0.0.1:60392",
      "user_agent": "ffmpeg/go2rtc",
      "medias": [
        "video, recvonly, H.264 High 3.1",
        "audio, recvonly, OPUS/48000/2"
      ],
      "receivers": [
        "96 H264, bytes=926436, senders=1",
        "97 OPUS/48000/2, bytes=91951, senders=1"
      ],
      "recv": 1032400
    }
  ],
  "consumers": [
    {
      "type": "WebRTC/WebSocket async passive consumer",
      "remote_addr": "udp4 srflx 179.106.189.52:60927 related 0.0.0.0:0",
      "user_agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/113.0.0.0 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, L16"
      ],
      "senders": [
        "102 H264, bytes=926436, receivers=1",
        "111 OPUS/48000/2, bytes=91951, receivers=1"
      ],
      "send": 1034539
    }
  ]
}

[felipecrs]

I initially thought it was because my Rpi was too slow, but I don't think it's the case because:

1. I tried reducing the framerate to like <5 FPS on the DVR
2. I tried reducing the resolution to 320x240 on the DVR

None helped the audio in WebRTC.

[felipecrs]

Maybe this is related to #387.

[felipecrs]

Probably related to #361 as well.

[AlexxIT]

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

[felipecrs]

Issue is fixed indeed! Thanks a ton!

[AlexxIT]

Very stupid fix. I think no one knows why it is works.