.. _build_pcie_app:

PCIe Pipeline Adaptation
========================

In the :ref:`previous section <building_first_pipeline_with_palette>`, you learned how to build a basic pipeline and test it on the DevKit. However, that setup doesn’t yet allow you to transfer data from the host to the DevKit or retrieve data 
from the DevKit back to the host over PCIe. To enable this functionality, you’ll need to modify the pipeline to incorporate PCIe plugins. Here’s the general concept:

- Update the ``gst-launch`` command in the ``application.json`` by :
    
    - replacing the ``simaaisrc`` input plugin with the ``pciesocsrc`` plugin, and include the required parameters.
    - swapping the ``simple_overlay`` output plugin for the ``pciesocsink`` plugin, and provide the necessary parameters.
    - Make other necessary changes to ``application.json`` to accommodate to the PCIe system architecture.

- Develop a host-side application using the PCIe Host Side C++ or Python APIs to exchange data with the DevKit. 
- Alternatively, you can utilize the ``pciehost`` host side plugin provided by SiMa to test the pipeline without having to write any host side code. 

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