cec-dotnet

.NET client applications for libCEC, the cross-platform library for controlling CEC-capable HDMI hardware (TVs, AV receivers, etc.) — primarily via Pulse-Eight's USB-CEC adapter.

This repository contains the managed (C#) apps only. It is not standalone: it is consumed as the src/dotnet git submodule of libCEC and builds against the LibCecSharp binding that libCEC produces. See Relationship to libCEC below.

What's in here

Project	Path	Description
cec-tray	src/LibCecTray	Windows system-tray application (cec-tray.exe) to configure the adapter, map keys to applications (Kodi, Windows Media Center, foreground app), and control connected CEC devices. WinForms, net8.0-windows (Windows only).
CecSharpTester	src/CecSharpTester/netcore	Minimal console sample showing how to open the adapter and log CEC traffic. Targets net8.0, so it runs anywhere the binding does.

The tester compiles the shared sample source src/CecSharpTester/CecSharpClient.cs and is the best starting point for learning the API.

Relationship to libCEC

The C# code here talks to libCEC through the LibCecSharp binding, not directly. The binding exposes the managed CecSharp namespace (LibCecSharp, LibCECConfiguration, CecCommand, CecCallbackMethods, …).

That binding is not part of this repository — it lives in the libCEC repo at src/dotnetlib and produces LibCecSharp.dll. It is a single, pure-C# assembly that binds the native library through P/Invoke over libCEC's C API, targets net8.0, and builds with the .NET SDK (no MSVC /clr). It replaced two Windows-only C++/CLI wrappers (LibCecSharp for .NET Framework and LibCecSharpCore for net8.0); both apps here now reference the one assembly.

The build layers are:

cec-tray / CecSharpTester        (this repo, C#)
        │  references
        ▼
LibCecSharp.dll                  (libcec/src/dotnetlib — pure C# P/Invoke binding, the CecSharp namespace)
        │  P/Invoke
        ▼
cec.dll / libcec.so              (libcec/src/libcec, native C/C++ engine)

The .csproj files here reference the binding by HintPath into libCEC's shared output folder, e.g.:

<Reference Include="LibCecSharp">
  <HintPath>..\..\..\..\build\$(Configuration)\$(Platform)\net8.0\LibCecSharp.dll</HintPath>
</Reference>

so the binding (and therefore libCEC) must be built before these apps.

Building

cec-tray is Windows-only (WinForms); the CecSharpTester console sample is net8.0 and runs anywhere. Build them through libCEC's orchestrator, which builds the native library and the LibCecSharp binding, generates these projects from their .in templates, and then compiles the apps in the right order.

From a checkout of libCEC:

git clone https://github.com/Pulse-Eight/libcec
cd libcec
git submodule update --init --recursive     # checks out this repo into src/dotnet
python windows\create-installer.py           # builds cec.dll, the wrappers, and these apps

Useful flags (run from libCEC): -ni builds everything but skips packaging the installer; -vs generates the Visual Studio project files for development; -a {x64,x86,arm64} selects the architecture. See libCEC's windows/ and its CLAUDE.md/README for the full toolchain requirements (Visual Studio, CMake, Python 3.12+).

Build artifacts land in libCEC's build\<Configuration>\<Platform>\net8.0\: cec-tray.exe and CecSharpTester.exe, alongside LibCecSharp.dll. Running them needs the .NET 8 Desktop Runtime (the installer offers to install it).

Note: several project files here (*.csproj, Properties/AssemblyInfo.cs) are generated from .in templates by libCEC's cmake step so the version number is substituted in. Edit the .in file, not the generated file.

Once built, the solution project/cec-dotnet.sln can be opened in Visual Studio for development and debugging.

Getting a device

The USB-CEC adapter these apps drive is available from Pulse-Eight: https://www.pulse-eight.com/.

License

Dual-licensed under the GNU GPL v2 (or later) — see COPYING — or a commercial license from Pulse-Eight. Contact license@pulse-eight.com for commercial licensing.