flags. If a global_alpha value != 1 is set for the rectangle, the caller should set the #GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA flag if he wants to apply global-alpha himself. If the flag is not set global_alpha is applied internally before returning the pixel-data.
a #GstBuffer holding the ARGB pixel data with #GstVideoMeta set. This function does not return a reference, the caller should obtain a reference of her own with gst_buffer_ref() if needed.
Retrieves the pixel data as it is. This is useful if the caller can do the scaling itself when handling the overlaying. The rectangle will need to be scaled to the render dimensions, which can be retrieved using gstvideo.video_overlay_rectangle.VideoOverlayRectangle.getRenderRectangle.