Sets the given link function for the pad. It will be called when
the pad is linked with another pad.
The return value GST_PAD_LINK_OK should be used when the connection can be
made.
The return value GST_PAD_LINK_REFUSED should be used when the connection
cannot be made for some reason.
If link is installed on a source pad, it should call the GstPadLinkFunction
of the peer sink pad, if present.
Sets the given link function for the pad. It will be called when the pad is linked with another pad. The return value GST_PAD_LINK_OK should be used when the connection can be made. The return value GST_PAD_LINK_REFUSED should be used when the connection cannot be made for some reason. If link is installed on a source pad, it should call the GstPadLinkFunction of the peer sink pad, if present.