libdrmtap-sys

Raw FFI bindings for libdrmtap — a C library for capturing Linux screen framebuffers via DRM/KMS.

What is libdrmtap?

libdrmtap captures screen contents at the kernel level using DRM/KMS APIs. Unlike PipeWire/portal-based capture, it works:

At the login screen (GDM, SDDM, LightDM)
Without user interaction (no "Select screen to share" prompt)
On Wayland (bypasses the compositor security model)
Headless (no display server needed)

⚠️ Testing Status

Verified working: virtio_gpu (QEMU/Parallels VMs), Intel Meteor Lake (i915, dual 3840x2160, EGL CCS detiling of the tiled/compressed framebuffer), and NVIDIA Jetson Orin Nano (nvidia-drm, Wayland).

The AMD (amdgpu) backend is implemented but not yet validated on real hardware.

If you test AMD or other configurations, please report results via GitHub Issues.

Requirements

Linux with DRM/KMS support (kernel 4.20+ for the tiled/modifier framebuffer path, i.e. Ubuntu 20.04+; linear/VM framebuffers work on older kernels)
A C compiler — the embedded C sources are compiled statically at build time. There is no system libdrmtap install, meson install, or pkg-config lookup of a shared library.
libdrm development headers (located via pkg-config), plus EGL, OpenGL ES 2, libseccomp, and libcap (and their -dev headers) — the crate links these.

Usage

This is a -sys crate with raw FFI bindings. For a safe wrapper, use libdrmtap.

use libdrmtap_sys::*;
use std::ptr;

unsafe {
    let ctx = drmtap_open(ptr::null());
    if !ctx.is_null() {
        let driver = drmtap_gpu_driver(ctx);
        // ... capture frames ...
        drmtap_close(ctx);
    }
}

License