Jordan Petridіs authored Jun 11, 2020 and Tim-Philipp Müller committed Oct 14, 2020

gst_element_class_set_metadata is meant to only be used with
static or inlined strings, which isn't the case for the 2 elements
here resulting in use-after-free later on.

https://gstreamer.freedesktop.org/documentation/gstreamer/gstelement.html?gi-language=c#gst_element_class_set_static_metadata

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