c_cxx

This directory contains a few C/C++ sample applications for demonstrating onnxruntime usage:

1. (Windows and Linux) fns_candy_style_transfer: A C application that uses the FNS-Candy style transfer model to re-style images. It is written purely in C, no C++.
2. (Windows only) MNIST: A windows GUI application for doing handwriting recognition
3. (Windows only) imagenet: An end-to-end sample for the ImageNet Large Scale Visual Recognition Challenge 2012 - requires ATL libraries to be installed as a part of the VS Studio installation.
4. model-explorer: A commandline C++ application that generates random data and performs model inference. A second C++ application demonstrates how to perform batch processing. (TODO: Add CI build for it)
5. OpenVINO_EP: Using OpenVino execution provider on the squeezenet model (TODO: Add CI build for it)
6. opschema_lib_use (TODO: Add CI build for it)

How to build

Note: These build instructions are for the Windows examples only.

Prerequisites

1. Visual Studio 2019 or 2022
2. cmake(version >=3.13)
3. (optional) libpng 1.6

Install ONNX Runtime

Option 1: download a prebuilt package

You may get a prebuilt onnxruntime package from https://github.com/microsoft/onnxruntime/releases/. For example, you may download onnxruntime-win-x64-***.zip and unzip it to any folder. The folder you unzip it to will be your ONNXRUNTIME_ROOTDIR path.

Option 2: build from source

If you'd like to build from source, the full build instructions are here.

Please note you need to include the "--build_shared_lib" flag in your build command.

e.g. from Developer Command Prompt or Developer PowerShell for the Visual Studio version you are going to use, build ONNX Runtime at least these options:

.\build.bat --config RelWithDebInfo --build_shared_lib --parallel

By default the build output will go in the .\build\Windows\<config> folder, and "C:\Program Files\onnxruntime" will be the installation location.

You can override the installation location by specifying CMAKE_INSTALL_PREFIX via the cmake_extra_defines parameter.

e.g.

.\build.bat --config RelWithDebInfo --build_shared_lib --parallel --cmake_extra_defines CMAKE_INSTALL_PREFIX=D:\onnxruntime

Run the below command to install onnxruntime. If installing to "C:\Program Files\onnxruntime" you will need to run the command from an elevated command prompt.

cmake --install .\build\Windows\RelWithDebInfo --config RelWithDebInfo

Build the samples

Open Developer Command Prompt or Developer PowerShell for the Visual Studio version you are going to use, change your current directory to samples\c_cxx, and run the below command.

• You may omit the "-DLIBPNG_ROOTDIR=..." argument if you don't have the libpng library.
• You may omit "-DONNXRUNTIME_ROOTDIR=..." if you installed to "C:\Program Files\onnxruntime", otherwise adjust the value to match your ONNX Runtime install location.
• You may append "-Donnxruntime_USE_CUDA=ON" or "-Donnxruntime_USE_DML=ON" to the last command args if your onnxruntime binary was built with CUDA or DirectML support respectively.

mkdir build && cd build
cmake .. -A x64 -T host=x64 -DONNXRUNTIME_ROOTDIR=D:\onnxruntime -DLIBPNG_ROOTDIR=C:\path\to\your\libpng\binary

You can open and build the solution using Visual Studio,

devenv onnxruntime_samples.sln

or build it from the command line using msbuild

msbuild onnxruntime_samples.sln /p:Configuration=Debug|Release