Getting started with LT-300 series capture cards on Linux and Windows

1What gets installed

One installer sets up everything you need on the host computer:

• Drivers for the LT boards plugged into the host.
• The agent ( lt300agent ), a service that runs in the background and serves the LT API. Every tool and application talks to the boards through it.
• ecurl, a command-line tool to send API requests, preview and record.
• ecap, a graphical application to preview, capture and record — try it in your browser.

The SDK is a separate download with the API documentation, client libraries and examples in Go, C++ and Python, plus C# since v1.5.0.

2Install on Windows

Run the latest installer ( .exe ). It installs the drivers, tools and services and removes the previous version if needed. The agent then starts automatically, now and at every boot.

• The boards appear in the Device Manager under Sound, video and game controllers.
• Every board input is available as a DirectShow filter, so it works in any DirectShow-compatible application while the agent is running.
• To uninstall, run the installer again and choose Remove, or use Apps & features.

3Install on Linux

Extract the latest Linux archive ( .tar.gz ) and run the install script it contains:

$ tar -xzf <install-archive>.tar.gz
$ cd <install-folder>
$ sudo ./<install-script>.sh

The agent starts automatically after a successful installation and at every boot. If the installation fails, check the installer's log file and contact us. To uninstall, run the uninstall script from the installation directory.

On Linux the inputs are exposed through V4L2 drivers, so they work with any V4L2 or GStreamer application. V4L2 filters are off by default: see Use the inputs in your own software to enable them.

4Control the agent

The installer adds the agent and the tools to the PATH . These commands need administrator rights (an elevated prompt on Windows, sudo on Linux):

$ lt300agent status    # is the agent running?
$ lt300agent version   # agent version
$ lt300agent stop
$ lt300agent start

Board firmware

When the agent starts, it updates the board firmware automatically if needed. This can take up to 2 minutes depending on the board, and the agent is unavailable until it finishes. To update manually, stop the agent first:

$ lt300agent stop
$ lt300agent update
$ lt300agent start

5Check your board

With the agent running, ask it for its version and for the boards it sees. Board indexes start at 0 (up to two boards per host):

$ ecurl get lt300:/      # agent information
$ ecurl get lt300:/0     # board 0: model, serial number, firmware

Each model has its own inputs. Use these names in every URL:

Then check the signal on an input. "signal": "locked" means a valid source is connected; the response also gives the resolution, frame rate, pixel format and audio format:

$ ecurl get lt300:/0/sdi-in/0

6Preview, snapshot and record

play and rec run until you press Ctrl+C .

Live preview

$ ecurl play lt300:/0/hdmi-in/0 -d media=video/yuyv   # video
$ ecurl play lt300:/0/hdmi-in/0 -d media=audio/pcm    # audio

Snapshot

$ ecurl get lt300:/0/sdi-in/0/file -d type=image/jpeg

Record to MP4

$ ecurl rec lt300:/0/hdmi-in/0/file -d media=video/mp4

Hardware encoding, bitrate, file splitting and multi-channel recording are covered in Recording 4K video with hardware encoding. You can also build these commands with the ecurl command generator.

7Use the inputs in your own software

Besides the API, the agent exposes every input as a standard capture device: DirectShow filters on Windows, V4L2 devices on Linux. Both are managed by the agent, so they only work while it runs. They are switched on or off in the optional agent configuration file, placed next to the agent executable (a default one ships in the agent folder):

On Linux, once v4l2Filters is enabled and the agent restarted, list the devices and use them from GStreamer, OpenCV or FFmpeg:

$ v4l2-ctl --list-devices

8Next steps

• Explore every endpoint in the API programmer guide.
• Record with NVENC, Quick Sync or AMF: hardware encoding guide.
• Draw text, logos and multi-view layouts: canvas overlay guide.
• Run AI on live video: YOLO on Jetson with the LT-313.