This section of the appendix will discuss shortly what changes to plugins will be needed to quickly and conveniently port most applications from &GStreamer;-0.8 to &GStreamer;-0.9, with references to the relevant sections in this Plugin Writer's Guide where needed. With this list, it should be possible to port most plugins to &GStreamer;-0.9 in less than a day. Most functions returning an object or an object property have been changed to return its own reference rather than a constant reference of the one owned by the object itself. The reason for this change is primarily threadsafety. This means, effectively, that return values of functions such as gst_element_get_pad (), gst_pad_get_name () and many more like these have to be free'ed or unreferenced after use. Check the API references of each function to know for sure whether return values should be free'ed or not. base classes, async capsnego (caps-on-buffer), async for sinks, bytestream dead / pull_range, direct scheduling, etc.