[PATCH v2 0/6] MR61: winegstreamer: Dynamic transform stream format change support.

[Rémi Bernon (@rbernon)]

Compared to last attempt, I moved the format pointer to a dedicated `wg_transform_read_data` parameter instead of a property of the sample. Most of the transforms use `NULL` there as they don't expect or support format change. H264 decoder passes a transform format member where it tracks the current stream format.

--
  v2: winegstreamer: Expose output media type attributes from the stream format.
      winegstreamer: Support wg_transform output format change events.
      winegstreamer: Track caps changes and keep them with the output buffers.
      winegstreamer: Only filter video caps attributes when format explicitely uses 0.
      winegstreamer: Set wg_transform output sample size on gst_buffer_map failure.
      winegstreamer: Append a videoconvert element to wg_transform video output.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/61