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   Copyright 2021 Xilinx, Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
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VVAS GStreamer Inference Meta Data Structures
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This section covers details about the GStreamer Meta Data structures to host inference meta data produced by the machine learning (ML) inference acceleration software libraries. This metadata structure stores the inferred data generated at multiple levels of ML operation into a single structure in a hierarchical way. This data structure combines, and stores metadata generated by detection and classification models.

The GStreamer plug-ins can set and get inference metadata from the GstBuffer by using the `gst_buffer_add_meta ()` API and `gst_buffer_get_meta ()` API, respectively.

*****************
GstInferenceMeta
*****************               

.. c:struct:: GstInferenceMeta

   GstInferenceMeta is the root node of the inference metadata. GstInferencePrediction hosts the actual inference metadata.

**Definition**

::

  struct GstInferenceMeta {
    GstMeta meta;
    GstInferencePrediction *prediction;
  };

**Members**

``meta``
  Buffer metadata

``prediction``
  Contains all the predictions associated to this node

***********************
GstInferencePrediction
***********************                     

.. c:struct:: GstInferencePrediction

   This structure represents the inference data generated from the ML operation

**Definition**

::

  struct GstInferencePrediction {
    GstMiniObject base;
    GMutex mutex;
    GstBuffer *sub_buffer;
    VvasInferPrediction prediction;
    void *reserved_1;
    void *reserved_2;
    void *reserved_3;
    void *reserved_4;
    void *reserved_5;
  };

**Members**

``base``
  private base object

``mutex``
  mutex

``sub_buffer``
  A buffer created from the main buffer

``prediction``
  VVAS core inference structure refe to :doc:`VVASInferPrediction <./vvas_infer_prediction>`

``reserved_1``
  for future extension

``reserved_2``
  for future extension

``reserved_3``
  for future extension

``reserved_4``
  for future extension

``reserved_5``
  for future extension


***************************
GstInferenceClassification
***************************                          

.. c:struct:: GstInferenceClassification

   This structure stores the results of the ML operation by the classification network

**Definition**

::

  struct GstInferenceClassification {
    GstMiniObject base;
    GMutex mutex;
    VvasInferClassification classification;
  };

**Members**

``base``
  private base object

``mutex``
  mutex

``classification``
  VVAS core inference structure :doc:`VVASInferClassification <./vvas_infer_classification>`