RTSP audio
RTSP Audio and Microphone Guide
If your RTSP camera has video but no sound, the issue is usually in the camera profile, audio codec, sub-stream selection, or player pipeline rather than the RTSP URL alone.
Quick checklist
- Enable microphone or audio input in the camera web interface.
- Check the selected stream profile. Some sub-streams are video-only.
- Prefer AAC or G.711 when available for broad compatibility.
- Test the RTSP URL in a tool that shows tracks, such as ffprobe.
- If converting RTSP to WebRTC, confirm the bridge supports the audio codec.
Common RTSP audio codecs
| Codec | Common in cameras | Notes |
|---|---|---|
| AAC | Modern cameras and NVRs | Usually the easiest choice for playback. |
| G.711 / PCMU / PCMA | Hikvision, Dahua, Amcrest, many ONVIF cameras | Reliable for surveillance audio, but some web pipelines need transcoding. |
| PCM | Some professional cameras | High compatibility in native apps, heavier bandwidth. |
| Opus | Rare directly from cameras | Often appears after RTSP is bridged to WebRTC. |
How to inspect an RTSP stream for audio
Use ffprobe to see whether the camera is actually sending an audio track. If ffprobe only shows a video stream, the issue is in the camera or selected profile.
Look for a second stream such as Audio: aac, Audio: pcm_mulaw, Audio: pcm_alaw, or Audio: pcm_s16le.
Audio-only RTSP streams
Some devices can expose an audio-only RTSP stream, but most security cameras publish audio as a second track inside a normal camera stream. If you need audio-only monitoring, first confirm the camera supports an audio profile, then test the exact URL in ffprobe or VLC.
WebRTC no audio after RTSP conversion
When RTSP is converted to WebRTC, audio may disappear even though the original RTSP stream has sound. WebRTC expects specific audio formats, and bridges may need to transcode G.711, PCM, or camera-specific audio into a browser-friendly track.
- Check whether the original RTSP stream has audio with ffprobe.
- Confirm the bridge advertises an audio track in SDP.
- Use AAC or G.711 on the camera when possible.
- Try the main stream and sub-stream; some brands only include audio on one profile.