84 lines
2.5 KiB
Text
84 lines
2.5 KiB
Text
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IO_URING and Video Output Example Code
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======================================
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:revision: 1.0
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:author: Hermann Voßeler
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:date: 8/2026
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This directory contains a example code to demonstrate reading data blocks
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continuously using the io_uring kernel interface. The loaded data is then
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fed to a video display pipeline based on OpenGL / EGL
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[red yellow-background]#Publish on Lumiera.org#
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////
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TIP: This demo code has been published on
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link:https://lumiera.org/research/videoDisplay/index.html[Lumiera.org]
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////
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Building the code
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-----------------
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As convenience, a CMake build system is provided, defining all library prerequisites.
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A typical invocation for a complete build might be...
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[source,sh]
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--------------
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cmake -S examples -B build
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cmake --build build -- -j4
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# clean tree with...
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cmake --build build --target clean
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--------------
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TIP: The `-j4` option tells make to use 4 cores concurrently to speed up the build.
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Furthermore, you might want to configure further options with a graphical GUI,
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e.g: `cmake-gui build`; this way you can configure individual library dependencies
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to point to custom locations.
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Use at least GCC-14
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~~~~~~~~~~~~~~~~~~~
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[red yellow-background]#TODO: still relevant?#
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Some older C++ compilers seem to have problems with a `constexpr` function used in 'commons.hpp'.
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Either comment out the line with the static assertion, or use at least GCC-14, which can be
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configured for CMake with
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-----
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cmake -S examples -B build -DCMAKE_CXX_COMPILER=g++-14
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-----
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Dependencies
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~~~~~~~~~~~~
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Although the prime objective of this demo is to show how to read a sequence of data blocks using io_uring,
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the practical example uses this technology to display video frames with an OpenGL pipeline. The framework
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is a simple GTK-3 application that integrates OpenGL through EGL (with GLEW). This explains why you
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need several distinct groups of dependencies to build the code. The build system only mentions the
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top-level dependencies; so either you have to install further transitive dependencies manually, or
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(preferrably) you might want to rely on the _package manager_ of a Linux distribution.
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The following list shows how to install the dependencies on Debian / Ubuntu.
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Basic build environment::
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+
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-----------
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apt install build-essential cmake
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-----------
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+
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Lib-uring::
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+
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-----------
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apt install liburing-dev
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-----------
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+
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Build a GTK-3 application with C++::
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+
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-----------
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apt install libgtkmm-3.0-dev
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-----------
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+
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EGL Video Display::
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+
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-----------
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apt install libx11-dev libglew-dev libegl-dev libgl-dev
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-----------
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