RTSP status and connection errors
Start from the exact status code or network symptom, then change one layer at a time.
RTSP 401 Unauthorized: Fix Camera Login Without Guessing
A layer-by-layer way to separate the camera account, URL parsing and authentication method when an RTSP stream returns 401.
02RTSP 404 Not Found: Find the Correct Camera Stream Path
Use the RTSP response to distinguish a reachable camera with a wrong resource path from a network or password failure.
03RTSP 461 Unsupported Transport: Switch TCP or UDP Correctly
Understand why RTSP SETUP fails with 461 and test an alternate RTP transport without changing unrelated settings.
04RTSP Timeout vs Connection Refused: What Each Error Proves
Use the timing and network response to decide whether to investigate routing, firewall rules or an inactive RTSP service.
05RTSP 454 Session Not Found: Repair a Lost Camera Session
Explain why a camera accepts setup but later loses the RTSP session, and how to test keep-alive and reconnect behavior.
Playback and continuity
Separate stream availability, media description, transport, decoding and timing before changing camera settings.
RTSP Plays Audio but No Video: A Codec-First Checklist
Diagnose an RTSP feed that carries audio while the picture stays black by inspecting advertised tracks and decoder support.
07RTSP Green Screen or Blocky Video: Isolate Decode vs Packet Loss
A controlled test for green frames, macroblocking and tearing in camera streams without random setting changes.
08RTSP Stops After a Few Minutes: Session, Wi-Fi or Camera Limit?
Use the repeatable failure interval to identify keep-alive, battery sleep, Wi-Fi and concurrent-session limits.
09RTSP Works in VLC but Not a Camera App: Compare the Right Layers
Turn a VLC success into useful evidence about the URL, codec, transport and authentication that another viewer needs.
10RTSP Camera Clock Drift: Fix Timestamps Before Comparing Events
Separate camera wall-clock time, RTP media time and viewer display time so multi-camera events remain trustworthy.
RTSP URLs and transport
Treat the URL, credentials, address family and RTP transport as separate variables that can fail independently.
RTSP Password Has @, # or %? Encode the URL Safely
Prevent reserved password characters from being misread as RTSP URI separators while avoiding credential leaks.
12RTSP URL with an IPv6 Camera Address: Brackets, Scope and Routing
Build an RTSP URI for an IPv6 literal and diagnose link-local scope or VPN routing issues.
13RTSP Main Stream vs Substream: Use Each for the Right View
Choose a high-detail main stream for inspection and a lower-bitrate substream for grids, remote links and constrained devices.
14RTSP over TCP vs UDP for Cameras: A Practical Test
Compare interleaved TCP and unicast UDP with the same camera, codec and network before choosing a default.
15RTSP SDP Explained: Read the Tracks Before Troubleshooting
Understand the media description returned by DESCRIBE and use it to identify codecs, payloads and control tracks.
Codecs and inspection tools
Inspect the advertised tracks and codec parameters before assuming a viewer or network problem.
RTSP H.264 Profile and Level: Why “H.264 Supported” Is Not Enough
Check profile, level, resolution and packetization when one H.264 camera stream works and another does not.
17RTSP H.265 / HEVC Compatibility: Test Before You Convert
Determine whether the camera, viewer and target device can carry and decode HEVC before adding a transcoder.
18RTSP AAC vs G.711 Audio: Choose a Camera Track That Plays
Compare common camera audio codecs and diagnose silent playback without confusing microphone settings with decoder support.
19Use ffprobe on an RTSP Camera Without Leaking the Password
A safe inspection workflow for codecs, tracks, resolution and transport with a redacted support output.
20How to Redact an RTSP URL for Support Without Breaking the Clue
Keep the scheme, port and path shape useful while removing credentials, private hosts and identifying query data.
ONVIF discovery and services
Discovery only locates a device service; media profiles, credentials and routing still require their own checks.
ONVIF Device Service URL: What the xaddr Actually Means
Understand the address returned by discovery and why the media stream URL may be different.
22ONVIF Discovery Across VLANs: Why Multicast Stops at the Router
Design a routed camera network where discovery failure does not get mistaken for media failure.
23ONVIF Port 3702 vs Camera Service Port: Do Not Mix Them Up
Separate WS-Discovery traffic from the HTTP or HTTPS endpoint used for ONVIF device and media calls.
24ONVIF Finds the Camera but No Video Appears: Next Checks
Move from discovery success to profile, stream URI, authentication, transport and codec checks in the right order.
25ONVIF Authentication Fails? Check Time Before Resetting Passwords
Explain how camera clock skew can invalidate signed ONVIF requests even when the username and password are correct.
ONVIF profiles and controls
Use registered profile conformance and exact model evidence instead of treating ONVIF as one universal feature flag.
ONVIF Profile S vs T: Which Camera Profile Matters Now?
Compare basic streaming with newer video, imaging, metadata and security capabilities using registered conformance.
27ONVIF Profile G: Recording, Search and Replay Explained
Know when Profile G matters for edge storage and recording retrieval, and when a live viewer does not need it.
28ONVIF Profile M: Metadata and Analytics Without the Hype
Separate standardized metadata transport from the quality, legality and operational value of the underlying analytics.
29How to Check Whether a Camera Is Really ONVIF Conformant
Use the official product database, exact model and firmware instead of marketplace claims or a generic brand statement.
30ONVIF PTZ Not Working: Verify Control Before Blaming Video
Diagnose a camera that streams correctly but will not pan, tilt or zoom through an ONVIF client.