How RTSP Works
RTSP separates stream control from stream delivery into two protocols. RTSP itself is a text-based control protocol similar to HTTP, running on TCP port 554 (or 8554 for alternate ports). A client sends RTSP commands — DESCRIBE (get stream capabilities), SETUP (configure how the stream will be delivered), PLAY (start the stream), PAUSE, and TEARDOWN (end the session) — to the streaming server. The server responds with session parameters.
The actual video and audio data travels over RTP (Real-time Transport Protocol), typically on UDP ports negotiated during the SETUP phase. UDP is preferred for streaming because it has lower latency than TCP and is resilient to loss — a dropped packet in a video stream causes a brief artifact rather than a buffer stall. RTP is accompanied by RTCP (RTP Control Protocol) for quality feedback and synchronization.
RTSP URLs and IP Camera Access
Every IP camera that supports RTSP exposes one or more stream URLs. The format is: rtsp://username:password@ip_address:port/path. Common paths vary by manufacturer: Hikvision uses /Streaming/Channels/101 for the main stream; Dahua uses /cam/realmonitor?channel=1&subtype=0; Reolink uses /h264Preview_01_main; Amcrest uses /cam/realmonitor?channel=1&subtype=0. Generic paths like /stream and /live are also common.
Many cameras expose two streams: a main stream (full resolution, high bitrate — often 4K or 1080p at 4–8 Mbps) and a sub-stream (lower resolution, lower bitrate — suitable for continuous recording or thumbnails). The sub-stream reduces NVR storage requirements and processing load for continuous 24/7 recording.
Playing and Recording RTSP Streams
VLC media player can play any RTSP stream directly: Media → Open Network Stream → enter the rtsp:// URL. ffmpeg can capture and transcode RTSP streams: ffmpeg -i rtsp://user:pass@camera_ip:554/stream -c copy output.mp4. FFmpeg is the backend used by most NVR software and Home Assistant camera integrations.
Home Assistant integrates IP cameras via the generic camera integration using an RTSP still-image URL or via the ffmpeg integration for live streaming. Frigate NVR is a popular Home Assistant companion that uses ffmpeg to record RTSP streams with local AI object detection (person, car, animal) running on your hardware — requiring no cloud service.
Common RTSP URL Formats by Camera Brand
| Brand | Main Stream URL Pattern | Sub-Stream URL Pattern | Default Port |
|---|---|---|---|
| Hikvision | rtsp://user:pass@ip/Streaming/Channels/101 | rtsp://user:pass@ip/Streaming/Channels/102 | 554 |
| Dahua | rtsp://user:pass@ip/cam/realmonitor?channel=1&subtype=0 | rtsp://user:pass@ip/cam/realmonitor?channel=1&subtype=1 | 554 |
| Reolink | rtsp://user:pass@ip//h264Preview_01_main | rtsp://user:pass@ip//h264Preview_01_sub | 554 |
| Amcrest | rtsp://user:pass@ip/cam/realmonitor?channel=1&subtype=0 | rtsp://user:pass@ip/cam/realmonitor?channel=1&subtype=1 | 554 |
| Axis | rtsp://user:pass@ip/axis-media/media.amp | rtsp://user:pass@ip/axis-media/media.amp?resolution=640x480 | 554 |
| Generic ONVIF | Discoverable via ONVIF Device Manager | Discoverable via ONVIF Device Manager | 554 |
Frequently Asked Questions
What is the difference between RTSP and HTTP video streaming?
RTSP is a control protocol for streaming media sessions — it manages connection setup, playback control, and teardown. HTTP streaming (HLS, DASH) packages video into short segments (2–6 seconds) served over standard HTTP. RTSP+RTP provides lower latency (under 1 second) and is used by IP cameras and professional video systems. HLS/DASH provides better compatibility with web browsers and CDNs but has 5–30 second latency. Use RTSP for live camera feeds; use HLS for web video delivery.
How do I find my IP camera's RTSP URL?
Check the camera's manual or the manufacturer's support website — RTSP URL formats are usually documented. Use the ONVIF Device Manager (a free Windows application) to auto-discover ONVIF-compatible cameras on your network and retrieve their RTSP URLs automatically. Many cameras also show the RTSP URL in their web interface under network settings or video settings.
Is RTSP encrypted?
Standard RTSP on port 554 is unencrypted. RTSPS (RTSP over TLS, port 322) provides encrypted control, and SRTP (Secure RTP) encrypts the media stream. Most home IP cameras do not support SRTP or RTSPS — they rely on network-level security (isolating cameras on a dedicated IoT VLAN without internet access). Never expose RTSP ports directly to the internet — always access cameras through a VPN.
What is ONVIF and how does it relate to RTSP?
ONVIF (Open Network Video Interface Forum) is a standards body that defines interoperability specifications for IP cameras, NVRs, and video management software. ONVIF-compliant cameras expose a standardized discovery and configuration API (SOAP-based web service) plus RTSP for video streaming. The ONVIF Profile S specification includes RTSP streaming. Using ONVIF-compatible hardware ensures your camera works with any ONVIF-compatible NVR without vendor lock-in.