Create a Command Line Tool using CMake on Ubuntu#

This topic describes the steps needed to configure a CMake project for C++ Command Line Tool. These steps have been verified to work on Ubuntu 22.04.3 LTS.

Test that you have all tools installed#

C++ Compiler (g++):

g++ --version

CMake:

cmake --version

ninja:

ninja --version

If you don’t have those tools follow the steps in the Setup C++ development environment on Ubuntu post to configure a C++ development environment.

Create the project directory#

mkdir -p ~/avblocks/cmake/simple-converter

Create the CMake project#

Switch to the project directory:

cd ~/avblocks/cmake/simple-converter

Add src/main.cpp:

#include <iostream>

int main() {
  std::cout << "Hello AVBlocks!\n";
}

Add CMakeLists.txt:

cmake_minimum_required(VERSION 3.16)

project(simple-converter)

add_executable(simple-converter src/main.cpp)

Add build.sh:

#!/usr/bin/env bash

mkdir -p ./build/debug
pushd ./build/debug
    cmake -G 'Ninja' -DCMAKE_BUILD_TYPE=Debug  ../.. && \
    ninja
    ret=$?
popd  

Add .gitignore:

.DS_Store
.cache/
build/

You should end up with the following directory structure:

tree -a -L 2 simple-converter

simple-converter
├── .gitignore
├── CMakeLists.txt
├── build.sh
└── src
    └── main.cpp

Test the build#

chmod +x build.sh

./build.sh

Update for AVBlocks#

Download the 64 bit version of AVBlocks for C++ (Linux). The file you need will have a name similar to avblocks-v3.0.1-demo.1-linux.tar.gz except for the version number which may be different.
Extract the archive in a location of your choice, then copy the include and lib directories to the avblocks subdirectory of the CMake project directory. The CMake project directory is the directory that contains the CMakeLists.txt file.

You should end up with a directory structure similar to the following:
```
simple-converter
├── .gitignore
├── CMakeLists.txt
├── avblocks
│   ├── include
│   └── lib
├── build.sh
└── src
    └── main.cpp
```
Replace the contents of .gitignore with this code:
```
.DS_Store
.cache/
build/
avblocks/
```

Replace the contents of CMakeLists.txt with this code:

cmake_minimum_required(VERSION 3.16)

project(simple-converter)
set (target simple-converter)

add_executable(${target})

# definitions for Debug x64
target_compile_definitions(${target} PUBLIC  _DEBUG)

# compile options for Debug x64
target_compile_options(${target} PRIVATE -std=c++17 -MMD -MP -MF)
target_compile_options(${target} PRIVATE -m64 -fPIC)
target_compile_options(${target} PRIVATE -g)

# includes
target_include_directories(${target} PUBLIC avblocks/include)

# libs
target_link_directories(${target} PRIVATE ${PROJECT_SOURCE_DIR}/avblocks/lib/x64)
target_link_libraries(${target} libAVBlocks64.so)

# sources
file(GLOB source "src/*.cpp")
target_sources(${target} PRIVATE ${source})

Replace the contents of main.cpp with this code:

//
//  main.cpp
//  simple-converter
//

#include <primo/avblocks/avb.h>
#include <primo/platform/reference++.h>
#include <primo/platform/ustring.h>

using namespace primo;
using namespace primo::codecs;
using namespace primo::avblocks;

int main(int argc, const char *argv[]) {
    Library::initialize();

    auto inputFile = primo::ustring("AAP.m4v");
    auto outputFile = primo::ustring("AAP.mp4");

    auto inputInfo = primo::make_ref(Library::createMediaInfo());
    inputInfo->inputs()->at(0)->setFile(inputFile.u16());

    if (inputInfo->open()) {
        auto inputSocket = primo::make_ref(Library::createMediaSocket(inputInfo.get()));
        auto outputSocket = primo::make_ref(Library::createMediaSocket(Preset::Video::Generic::MP4::Base_H264_AAC));
        outputSocket->setFile(outputFile.u16());

        auto transcoder = primo::make_ref(Library::createTranscoder());
        transcoder->inputs()->add(inputSocket.get());
        transcoder->outputs()->add(outputSocket.get());

        if (transcoder->open()) {
            transcoder->run();
            transcoder->close();
        }
    }

    Library::shutdown();
    return 0;
}

Build the project
```
./build.sh
```

Run the application#

Download the AAP.m4v HD movie from the Internet Archive and save it in the project directory.
Run the application:
```
./build/debug/simple-converter
```
Wait for the Transcoder to finish - it will take a few minutes. The converted file AAP.mp4 will be in the project directory.

Troubleshooting#

transcoder->open() may fail if there is already a file AAP.mp4 in the project directory. Delete AAP.mp4 to solve that.

AVBlocks for C++

Create a Command Line Tool using CMake on Ubuntu

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