Audio does not work in Live View

[ondrej-zary]

The speaker icon appears in Live View, turns green when clicked but no audio is heard.
Audio works fine in Recordings.

[origin2000]

Not a lot of info. my live view audio and video works flawless.
maybe you start with what version of lightnvr you're running.
what camera your are using. what your stream config looks like.
did you check the log for warings and errors. if there are any, what are they.

[ondrej-zary]

LightNVR 0.34.3 (Debian Trixie package), Hikvision cameras configured with H.264 video + AAC audio.

The default on the cameras was G.711 but I saw in logs that it gets converted to AAC - so I changed it to AAC to avoid conversion and lower the CPU usage as much as possible.

The only warnings in the logs are about zero tier multipliers in database.

[origin2000]

I haven't dug into the code yet, but I think I can explain what's happening.

LightNVR uses go2rtc as a media proxy — it connects to your camera and relays the stream to multiple clients. Live streaming uses a WebRTC connection, while recordings are handled separately.

The issue likely comes down to codec compatibility. WebRTC has mandatory audio codec requirements per RFC 7874 — browsers are required to support Opus, G.711 A-law, and G.711 µ-law. AAC is not on that list.

If your camera is currently set to stream H.264/AAC, the video will come through fine on the live stream, but the audio will be silently dropped by the browser — there's no AAC support in WebRTC. Recordings work because the audio is written directly to the file without any codec negotiation.

To verify this: switch your camera's audio codec back to G.711 and check whether audio appears in the live stream. If it does, that confirms the cause. If not, we'll need to look elsewhere.

[ondrej-zary]

So recording requires AAC (because of MP4) but WebRTC does not support it. That sucks.

IIRC, the live audio worked before, most probably before I changed cameras from G.711 to AAC.

[origin2000]

"WebRTC does not support it. That sucks." -> I did not write the RFC Standard. Transcoding a G.711 to AAC audio stream on a Rockchip 3399T (6 Cores) costs about 1% of one A53 core. In exchange you get live video and audio plus a video with audio that plays on almost any player.