RTL TCP Client Multiplexer / Relay

rtlmux connects to one rtl_tcp server and lets multiple network clients share its sample stream. Clients receive the normal RTL TCP header and sample data, and supported tuner commands are forwarded to the upstream receiver.

The service also provides a small JSON status endpoint with connection and traffic statistics.

Download the static binary for your Linux system from the latest GitHub release:

# x86_64 / amd64
curl -LO https://github.com/slepp/rtlmux/releases/latest/download/rtlmux-linux-amd64
chmod +x rtlmux-linux-amd64

# Connect to rtl_tcp at 192.168.1.50:1234 and listen for clients on port 7878
./rtlmux-linux-amd64 -h 192.168.1.50 -p 1234 -l 7878

Release binaries are available for:

Point RTL TCP clients at the machine running rtlmux, port 7878 in the example above. Status is available at http://localhost:7879/stats.json.

rtlmux [OPTIONS]

  -h, --host=ADDRESS  rtl_tcp server address (default: localhost)
  -p, --port=PORT     rtl_tcp server port (default: 1234)
  -l, --listen=PORT   client listening port (default: 7878)
  -d, --delayed       connect upstream on demand and exit after the last client
  -r, --restart       restart after the last client disconnects
  -V, --version       print version and exit
      --help          print complete help and exit

The HTTP status endpoint uses the port immediately after the client port. For example, -l 7878 uses port 7879 for HTTP.

With -d alone, rtlmux exits after the last client disconnects. For a long-running standby service, use -d -r together:

./rtlmux-linux-armv7 -h 192.168.1.50 -p 1234 -l 7878 -d -r

This keeps the upstream connection idle until the first client arrives, then closes and resets it after the last client disconnects.

Multi-architecture images are published to Docker Hub for amd64, arm64, and ARMv7:

docker run --rm --network host slepp/rtlmux:latest \
  -h 192.168.1.50 -p 1234 -l 7878 -d -r

Version tags and latest are published from Git version tags. The edge image follows the repository's primary branch.

Install a C compiler, make, pkg-config, the libevent development files, and Python 3. On Debian or Ubuntu:

sudo apt-get install build-essential libevent-dev pkg-config python3
make
make test
sudo make install

make static creates a statically linked binary when static libevent libraries are installed. The Docker build provides a reproducible Alpine/musl static build:

docker build --target runtime -t rtlmux .

The generated command-line parser is committed to the repository. Install gengetopt and run make generate only when changing options.ggo.

Pushing a tag such as v1.1.0 builds static Linux binaries for amd64, arm64, and ARMv7, creates checksums, and publishes a GitHub release.

Docker Hub publishing uses the repository secrets DOCKERHUB_USERNAME and DOCKERHUB_TOKEN. Primary-branch builds publish edge; version tags publish the version and latest.