DeepStream uses an extensible standard structure for metadata. The basic metadata structure NvDsBatchMeta starts with batch level metadata, created inside the Gst-nvstreammux plugin. Subsidiary metadata structures hold frame, object, classifier, and label data. DeepStream also provides a mechanism for adding user-specific metadata at the batch, frame, or object level.

DeepStream attaches metadata to a Gst Buffer by attaching an NvDsBatchMeta structure and setting GstNvDsMetaType.meta_type to NVDS_BATCH_GST_META in the Gst-nvstreammux plugin. When your application processes the Gst Buffer, it can iterate over the attached metadata to find NVDS_BATCH_GST_META.

The function gst_buffer_get_nvds_batch_meta() extracts NvDsBatchMeta from the Gst Buffer. (See the declaration in sources/include/gstnvdsmeta.h.) See the deepstream-test1 sample application for an example of this function’s usage. For more details, see NVIDIA DeepStream SDK API Reference.