Direct answer
If audio plays, the RTSP session and at least one media track are working. Inspect the SDP or probe output for the video codec, profile, resolution and pixel format, then test a lower H.264 substream before changing the network.
Why this happens
The camera may advertise H.265 to a client that only decodes H.264, use an unsupported H.264 profile, omit the video track on the selected path, or send damaged packets while audio continues.
Separate stream availability, media description, transport, decoding and timing before changing camera settings.
A controlled test
Probe the same URL and compare the advertised audio and video streams. Then switch only the camera profile, keeping credentials and transport fixed.
Change one variable at a time. Keep the camera model, firmware, endpoint and account recorded; then test network reachability, protocol response, media transport and decoding as separate layers.
Use a dedicated view-only account and a trusted local diagnostic tool. Redact credentials, private addresses and identifying data before sharing output.
Diagnostic sequence
| Check | Action | Evidence of progress |
|---|---|---|
| Tracks | Confirm a video media section exists in SDP. | A video codec and payload are advertised. |
| Codec | Test an H.264 substream when the main stream is H.265. | Video appears without changing the endpoint. |
| Profile | Reduce profile, level or resolution temporarily. | The client decodes the simpler stream. |
| Packets | Compare TCP and UDP while watching decode errors. | A clean transport removes corruption without changing codec. |
Evidence to keep
Save the probe output with credentials removed. It provides the codec and track evidence needed to distinguish “no video track” from “cannot decode video.”
Boundary and safety note
Do not assume that a successful RTSP connection means every advertised codec is supported by every device.
For remote viewing, use a managed VPN instead of exposing RTSP or camera administration ports directly to the public internet.
SmartRTSP
SmartRTSP is a camera-focused RTSP and ONVIF viewer for Apple devices, Windows and Android. It fits direct viewing, discovery and multi-camera checks; keep a dedicated NVR or VMS when continuous recording, evidence export or centralized enterprise controls are required.
Frequently asked questions
Why can audio work when video does not?
RTSP can describe separate media tracks, and the client may decode one track but not the other.
Should I try H.264?
Yes, a documented H.264 substream is the fastest compatibility test when the main stream uses H.265.
Is this always a codec issue?
No. The video track can be missing or damaged in transport, so inspect the advertised tracks and decode errors.
Primary references
- IETF RFC 7826 — Real-Time Streaming Protocol 2.0
- FFmpeg — RTSP protocol options and examples
- MDN — Media container and codec formats on the web
Related SmartRTSP guide
Open related guideDiagnose an RTSP feed that carries audio while the picture stays black by inspecting advertised tracks and decoder support.