We should not return a NULL in transform_caps() function. The NULL
will generate a assert of:
"transform_caps returned caps which are not a real subset of the
filter caps"
in transform base class.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/922>
GstCaps *ret;
if (base_filter->display && !gst_gl_base_filter_find_gl_context (base_filter))
- return NULL;
+ return gst_caps_new_empty ();
context = gst_gl_base_filter_get_gl_context (base_filter);