Please refer to the gst-nvinfer source code. /opt/nvidia/deepstream/deepstream/sources/gst-plugins/gst-nvinfer
DeepStream SDK FAQ - Intelligent Video Analytics / DeepStream SDK - NVIDIA Developer Forums
output-tensor-meta=1 does not change the inference time directly. But it will output tensorRT output and skip the post processing, the processing time will be less than output-tensor-meta=0.