libdrmtap

Safe Rust wrapper for libdrmtap — DRM/KMS screen capture for Linux.

Capture the screen at the kernel level: login screens, Wayland, headless — no user prompts.

⚠️ Testing Status

Tested on virtio_gpu (QEMU/Parallels VMs) only.

Intel, AMD, and Nvidia backends are implemented but not yet validated on real hardware. If you test on real GPUs, please report results.

Example

use libdrmtap::DrmTap;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut tap = DrmTap::open(None)?;

    println!("GPU: {}", tap.gpu_driver().unwrap_or("unknown".into()));

    // List displays
    for d in tap.list_displays()? {
        println!("{}: {}x{}@{}Hz", d.name, d.width, d.height, d.refresh_hz);
    }

    // Capture a frame with mapped pixel data
    let frame = tap.grab_mapped()?;
    println!("Captured: {}x{} stride={}", frame.width(), frame.height(), frame.stride());

    if let Some(pixels) = frame.data() {
        println!("First pixel (BGR): {:02x}{:02x}{:02x}",
                 pixels[0], pixels[1], pixels[2]);
    }

    Ok(())
}

Features

• DrmTap::open() — auto-detect GPU and display
• grab() — zero-copy DMA-BUF fd (for hardware encoders)
• grab_mapped() — mmap'd pixel data (for software access)
• get_cursor() — cursor position + ARGB image
• list_displays() — enumerate connected monitors
• displays_changed() — hotplug detection

Requirements

• Linux with DRM/KMS
• libdrmtap C library installed
• For unprivileged capture: drmtap-helper with cap_sys_admin+ep

License

MIT