xvinfo

xvinfo [options]

-display <display>
    Specifies the X server to contact. This option is useful for querying information from a remote display or a specific display on the local machine (e.g., `:0.0`).

-v
    Causes xvinfo to print a comprehensive list of all visual IDs and types supported by the X server, in addition to the standard Xv adaptor information. This provides deeper insight into the server's rendering capabilities.

-h
    Prints a brief usage message detailing the command's available options and then exits immediately.

xvinfo is a command-line utility for the X Window System that provides detailed information about the XVideo (Xv) extension adaptors available on the current X server. The XVideo extension enables video-aware applications to display video directly on an X server display, often leveraging hardware acceleration for operations like scaling, color space conversion, and de-interlacing.

xvinfo enumerates each Xv adaptor found, detailing its capabilities such as supported input and output formats (e.g., YUV, RGB), available attributes (like brightness, contrast, hue, saturation, and gamma), unique port IDs, and associated video encodings. It's an essential tool for diagnosing Xv-related issues, verifying hardware video acceleration support, and understanding the video playback capabilities of a given X server setup. Developers and power users frequently use it to confirm the presence and functionality of Xv drivers and adaptors for optimal multimedia performance in Linux environments.

xvinfo's functionality is entirely dependent on the XVideo extension being present and enabled on the X server. If the extension is not found (e.g., on a headless server, a minimal X setup, or a Wayland session without XWayland), xvinfo will report "Xv extension not present" or similar.

The capabilities and attributes reported by xvinfo are specific to the graphics hardware and its installed drivers. Not all hardware supports all Xv features.

Modern desktop environments often use alternative display protocols (like Wayland) or rendering technologies (like OpenGL/Vulkan for textured video playback) that do not directly rely on the XVideo extension. In such cases, xvinfo's output might not reflect the full video acceleration capabilities of the system.

The XVideo extension is a critical component of the X Window System architecture designed to optimize video playback. It provides a standardized interface for applications to interact with graphics hardware for video-related tasks. Instead of requiring applications to perform computationally intensive operations like YUV-to-RGB conversion or scaling in software, Xv allows these tasks to be offloaded to the GPU. This results in smoother video playback, reduced CPU utilization, and often enables features like hardware-accelerated de-interlacing. xvinfo serves as the primary diagnostic tool to understand what specific Xv capabilities and hardware acceleration features are available on a given X server instance.

The XVideo (Xv) extension was developed as a crucial component of the X Window System to enable efficient video display within desktop environments. It provided a standardized API for applications to leverage hardware acceleration for video processing tasks like scaling, color space conversion, and direct video overlays, thereby improving performance and reducing CPU load. xvinfo emerged as the dedicated diagnostic tool to query and display the capabilities offered by this extension. Its development is intrinsically linked to the evolution of multimedia capabilities and hardware acceleration in desktop Linux, becoming a go-to utility for verifying and troubleshooting video playback performance on X11-based systems.

xrandr(1), xdpyinfo(1), xprop(1), glxinfo(1)