vaxp-background

A hardware-accelerated desktop background manager designed for X11 and Wayland. It supports static images, looping video wallpapers, and audio-reactive OpenGL shaders.

Architecture & Features

• Display Abstraction: Provides native backends for both Wayland (using wl_surface) and X11. EGL is used for OpenGL context creation and buffer swapping.
• Zero-Copy Video Rendering: Implements a highly optimized GStreamer pipeline (vaapidecodebin -> glupload). Video frames are decoded via VA-API and imported directly into OpenGL textures using DMA-BUF and EGLImage. This bypasses system RAM entirely, maintaining minimal CPU usage (~2-3% of a single core) even at high framerates.
• Audio-Reactive Shaders: A background thread continuously captures the default PulseAudio/PipeWire sink, calculating the RMS volume level. This float value is passed as a uniform to the fragment shader, enabling audio-driven visual effects (such as UV distortion or color-space manipulation).
• Dynamic Configuration: Uses inotify to monitor the configuration file. Changes to the background file path or audio effect index trigger real-time transitions without requiring a process restart.
• Layer Management: Implements a double-buffered layer system to handle smooth crossfade transitions between different images or videos.

Dependencies

Ensure the following libraries and development headers are installed:

• C11 Compiler, Meson, Ninja
• Wayland (wayland-client, wayland-egl)
• X11 (x11, xcomposite, xext, xfixes)
• EGL & OpenGL
• GStreamer 1.0 (gstreamer-1.0, gstreamer-gl-1.0, gstreamer-video-1.0)
• GStreamer Plugins: Base, Bad, and VA-API (for hardware decoding)
• PulseAudio (libpulse-simple, libpulse)
• iniparser

Build Instructions

meson setup build
ninja -C build

Execution

./build/vaxp-background

Configuration

The program monitors a configuration file (typically via iniparser format). When the Wallpaper path or AudioEffect index is modified, the application dynamically reloads the specified asset and stops/starts the audio analysis thread as needed to conserve resources.

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This project was developed by a team from the vaxp organization as part of the ecosystem.