dmf-mf-mediamtx

A fork of bluenviron/mediamtx that adds an MXL static source. Not an official MediaMTX release.

Upstream documentation applies to everything else this server does: mediamtx.org.

What the fork adds

A mxl:// static source. A path configured with source: mxl:///<runtime-root>/<domain>/<flow-id> opens that MXL flow through libmxl and republishes it over the server's existing RTSP, HLS, WebRTC and SRT outputs. Grains are read zero-copy from the node-local domain, and the reader is paced to the flow's nominal grain rate rather than polling the ring buffer at maximum speed.

Encoding shells out to ffmpeg, so no GPL-licensed code is linked into the binary.

Path options the fork adds, accepted by both the configuration file and the /v3/config/paths/* HTTP API: mxlFFmpegPath, mxlCodec, mxlH264Preset, mxlH264Profile, mxlH264Bitrate, mxlH264IDRPeriod.

Geometry and frame rate come from the flow, never from configuration. The encoder is given the rate as the fraction the flow declares, so a 60000/1001 flow is encoded at 59.94 rather than at a rounded 60. mxlH264IDRPeriod counts frames and defaults to half a second of them at that rate; a GOP the length of hlsSegmentDuration sits on the HLS muxer's cut comparison, which makes segments alternate between one and two of them.

x264's frame threading is fixed at four threads and is not configurable. Left to itself it takes one and a half threads per host core and holds a frame per thread before the first access unit comes back, which is 818 ms of added latency at 1080p59.94 on a 32-core node and more frames than the source will queue on a 128-core one.

Paths can be added and removed at runtime over the HTTP API with none present at boot; a newly added mxl:// path starts its source immediately.

Image

ghcr.io/qvest-digital/dmf-mf-mediamtx

Tags: the 7-character commit SHA for every build on main, latest for the head of main, and the bare version for an mxl-v* tag.

Building

The MXL source is cgo and links libmxl, so a plain go build needs pkg-config and libmxl present and fails without them. Dockerfile.mxl builds against go-mxl-builder, which ships libmxl under /opt/libmxl.

Every reader and writer sharing an MXL domain must link a byte-identical libmxl. ARG GO_MXL_TAG in Dockerfile.mxl is what pins it.

Branches

• main carries the fork.
• upstream-main tracks bluenviron/mediamtx unmodified and is the base for merging upstream changes.

License

MIT, unchanged from upstream. See LICENSE.