uStreamer is a lightweight and high-performance MJPEG-over-HTTP streaming server for Linux V4L2 capture devices. It is commonly used to stream HDMI/VGA capture input with low latency and high FPS, and is a core component in PiKVM-style KVM over IP setups.

Key Features

Streams MJPEG video over HTTP with broad browser and player compatibility
Multi-threaded JPEG encoding for higher FPS and better CPU utilization
Raspberry Pi hardware-assisted encoding options (V4L2 M2M), with legacy OpenMAX/MMAL support removed
Resilient behavior when a capture device disconnects, keeping the stream available until reconnection
DV-timings support to adapt resolution dynamically based on the source signal
Optional frame deduplication to reduce bandwidth when frames are unchanged
Can serve a simple web UI and static files via the built-in HTTP server
Optional systemd socket activation and UNIX domain socket streaming modes

Use Cases

HDMI/VGA capture streaming for KVM over IP solutions (BIOS-level access workflows)
Low-latency MJPEG streaming for lab equipment, embedded devices, and headless hosts
Network-efficient streaming for mostly-static video sources by dropping identical frames

Limitations and Considerations

Primarily targets MJPEG over HTTP; advanced camera control features found in some webcam streamers may not be included
Hardware encoding capabilities depend on kernel/driver support and the specific capture device

uStreamer is well-suited when you need reliable, low-latency MJPEG streaming with strong performance on constrained hardware. It fits especially well into remote management and KVM over IP scenarios where stability and FPS matter.