auto features = gst_caps_get_features (caps, 0);
// defined in gstd3d11memory.h
// #define GST_CAPS_FEATURE_MEMORY_D3D11_MEMORY "memory:D3D11Memory"
if (gst_caps_features_contains (features, GST_CAPS_FEATURE_MEMORY_D3D11_MEMORY)) {
// this is d3d11 caps
}