Create a Command Line Tool in Xcode on macOS#

This topic describes the steps needed to configure an Objective-C Command Line Tool in Xcode. These steps have been verified to work with Xcode 15.0.1, on macOS Ventura 13.5.2.

Create the Xcode project#

  1. Open Xcode, select Create New Project, pick macOS as a platform, pick Command Line Tool for Application

  2. Set Product Name to simple-converter, select Objective-C for language.

  3. Rename main.m to

  4. Download the 64 bit version of AVBlocks for C++ (macOS). The file you need will have a name similar to except for the version number which may be different.

  5. Extract the ZIP archive in a location of your choice, then copy the include and lib directories to the avblocks subdirectory of the Xcode project directory. The Xcode project directory is the directory that contains the simple-converter.xcodeproj project file.

    You should end up with a directory structure similar to the following:

    ├── avblocks
    │   ├── include
    │   └── lib
    ├── simple-converter
    │   └──
    └── simple-converter.xcodeproj
  6. In Xcode, select the simple-converter project in Xcode, and then the ‘Build Settings’ tab:

    • Under Apple Clang - Language - C++, set the C++ Language Dialect to C++17[-std=c++17]

    • Under Search Paths | Header Search Paths, add the $(PROJECT_DIR)/avblocks/include directory to the list

    • Under linking - General | Runpath Search Paths, add @executable_path to the list

    • Set the Build Products Path to $(PROJECT_DIR)/build

  7. In Xcode, select the ‘simple-converter’ target, and then the ‘Build Phases’ tab:

    • Expand the ‘Link Binary with Libraries’ section

    • Add the libAVBlocks.dylib from the $(PROJECT_DIR)/avblocks/lib/x64 directory.

  8. Replace the contents of with this code:

    //  simple-converter
    #import <Foundation/Foundation.h>
    #pragma clang diagnostic push
    #pragma clang diagnostic ignored "-Weverything"
    #include <primo/avblocks/avb.h>
    #include <primo/platform/ustring.h>
    #include <primo/platform/reference++.h>
    #pragma clang diagnostic pop
    using namespace primo;
    using namespace primo::codecs;
    using namespace primo::avblocks;
    int main(int argc, const char * argv[]) {
        @autoreleasepool {
            auto inputFile = primo::ustring(L"AAP.m4v");
            auto outputFile = primo::ustring(L"AAP.mp4");
            auto inputInfo = primo::make_ref(Library::createMediaInfo());
            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));
                auto transcoder = primo::make_ref(Library::createTranscoder());
                if (transcoder->open()) {
        return 0;
  9. Restart Xcode!!! Otherwise it will not pick the new Build Products Path

  10. Build the project ( ⌘B )

  11. Copy the file libAVBlocks.dylib from avblocks/lib/x64 to build/Debug.

Run the application#

  1. Download the AAP.m4v HD movie from the Internet Archive and save it in the build/Debug directory.

  2. Run the application in Xcode. Wait for the Transcoder to finish - it will take a few minutes. The converted file AAP.mp4 will be in the build/Debug directory.


  • You may get dyld: Library not loaded: @executable_path/libAVBlocks.dylib or a similar message. To fix that, copy the file libAVBlocks.dylib from avblocks/lib to build/Debug.

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