Gets the capabilities this pad can produce or consume.
Note that this method doesn't necessarily return the caps set by sending a
Event.caps - use get_current_caps for that instead. gst_pad_query_caps
returns all possible caps a pad can operate with, using the pad's CAPS query function, If the query fails, this function will return
filter, if not null, otherwise ANY.
When called on sinkpads filter contains the caps that upstream could produce in the order preferred by upstream. When called
on srcpads filter contains the caps accepted by downstream in the preferred order. filter might be
null but if it is not null the returned caps will be a subset of
filter.
Note that this function does not return writable Caps, use gst_caps_make_writable
before modifying the caps.
| this |
a Pad to get the capabilities of. |
| filter |
suggested Caps, or null |
|
the caps of the pad with incremented ref-count. |