Description Caps (capabilities) are lighweight refcounted objects describing media types. They are composed of an array of GstStructure. Caps are exposed on GstPadTemplate to describe all possible types a given pad can handle. They are also stored in the GstRegistry along with a description of the GstElement. Caps are exposed on the element pads using the gst_pad_get_caps() pad function. This function describes the possible types that the pad can handle or produce at runtime. Caps are also attached to buffers to describe to content of the data pointed to by the buffer with gst_buffer_set_caps(). Caps attached to a GstBuffer allow for format negotiation upstream and downstream. A GstCaps can be constructed with the following code fragment: A GstCaps is fixed when it has no properties with ranges or lists. Use gst_caps_is_fixed() to test for fixed caps. Only fixed caps can be set on a GstPad or GstBuffer. Various methods exist to work with the media types such as subtracting or intersecting. Last reviewed on 2007-02-13 (0.10.10)