.. _developing_gstreamer_app_compiling_plugins:

Compiling SiMa.ai Plugins
#########################

In this section we will cross-compile the necessary SiMa.ai GStreamer plugins using Palette on our development 
machine, and then copy those plugins over to the MLSoC board. 

Creating an application directory on the MLSoC board
====================================================

Before continuing, let's create a directory for our SiMa.ai Gstreamer plugins, and one where we will store all application files while we develop, test and debug the pipeline.
On the MLSoC board, create the following directories:

.. code:: console

    davinci:~$ pwd
        /home/sima
    davinci:~$ mkdir gst-plugins resnet50_example_app
    davinci:~$ mkdir resnet50_example_app/data resnet50_example_app/models
    davinci:~$ ls
        gst-plugins  resnet50_example_app

Compiling the plugins
=====================

In order to use the SiMa.ai gstreamer plugins, we need to cross-compile them from source, and then copy them over to the board.
In this example, we will need to compile the following plugins: ``simaaisrc``, ``simaaiprocesscvu``, and ``simaaiprocessmla``. 
Some plugins have some dependencies on ``dispatcher-lite`` so we will go ahead and build that as well.

#. From the Palette Docker container on your host machine, go to the directory ``/usr/local/simaai/plugin_zoo/gst-simaai-plugins-base/``

    .. code-block:: console

        sima-user@docker-image-id:/home$ cd /usr/local/simaai/plugin_zoo/gst-simaai-plugins-base/
        sima-user@docker-image-id:/usr/local/simaai/plugin_zoo/gst-simaai-plugins-base$ ls
            build  ci_jobs	CMakeLists.txt	core  gst

#. In order to compile the necessary plugins, run the make command:

    .. code-block:: console

        sima-user@docker-image-id:/usr/local/simaai/plugin_zoo/gst-simaai-plugins-base$ cd build/
        sima-user@docker-image-id:/usr/local/simaai/plugin_zoo/gst-simaai-plugins-base/build$ make gstsimaaisrc gstsimaaiprocesscvu gstsimaaiprocessmla dispatcher-lite
            ...
            [ 57%] Built target dispatcher-lite
            [ 78%] Built target gstsimaallocator
            [ 85%] Building CXX object gst/processmla/CMakeFiles/gstsimaaiprocessmla.dir/gstsimaaiprocessmlastandalone.cpp.o
            [ 92%] Building CXX object gst/processmla/CMakeFiles/gstsimaaiprocessmla.dir/gstsimaaiprocessmla.cpp.o
            [100%] Linking CXX shared library libgstsimaaiprocessmla.so
            [100%] Built target gstsimaaiprocessmla
            [100%] Built target dispatcher-lite

#. To verify that all of the correct plugins/libraries were successfully built:

    .. code-block:: console

        sima-user@docker-image-id:/usr/local/simaai/plugin_zoo/gst-simaai-plugins-base/build$ find ./gst/* | grep "\.so"
            ./gst/processcvu/libgstsimaaiprocesscvu.so
            ./gst/processmla/simaai/src/dispatcher-lite-build/libgstsimacore-lite.so
            ./gst/processmla/libgstsimaaiprocessmla.so
            ./gst/simaaisrc/libgstsimaaisrc.so

    .. note::

        You might see more plugins already pre-compiled.

#. To copy the plugins over to the MLSoC, create a target directory on the MLSoC board first (in this case ``/home/sima/gst-plugins``) and then copy them over:

    .. code-block:: console

        sima-user@docker-image-id:/usr/local/simaai/plugin_zoo/gst-simaai-plugins-base/build$ scp \
        ./gst/processcvu/libgstsimaaiprocesscvu.so \
        ./gst/processmla/simaai/src/dispatcher-lite-build/libgstsimacore-lite.so \
        ./gst/processmla/libgstsimaaiprocessmla.so \
        ./gst/simaaisrc/libgstsimaaisrc.so \
        sima@<IP address of MLSoC>:/home/sima/gst-plugins

        libgstsimaaiprocesscvu.so                                                                                100% 2705KB   6.3MB/s   00:00    
        libgstsimacore-lite.so                                                                                   100%   59KB  13.9MB/s   00:00    
        libgstsimaaiprocessmla.so                                                                                100%  163KB  32.9MB/s   00:00    
        libgstsimaaisrc.so                                                                                       100%  103KB  23.6MB/s   00:00    

Now we have all of the plugins necessary to debug and build our example pipeline.

Conclusion and next steps
=========================

In this section, we: 

* Create an application directory in our MLSoC in order to house our plugins and resources as we develop and debug the application.
* Compiled the SiMa.ai Gstreamer plugins we will use in our ResNet50 GStreamer application.
* Copied all plugins over to the MLSoC directory we created for the GStreamer plugins.

In the next section, we will begin developing a ``gst-launch-1.0`` string one plugin at a time, and verify the correctness of the output at each stage.