Function that will be called by gst_audio_default_registry_mixer_filter()
so the caller can decide which mixer elements should be kept and returned.
When the mixer element is passed to the callback function, it is opened
and in READY state. If you decide to keep the element, you need to set it
back to NULL state yourself (unless you want to keep it opened of course).
Function that will be called by gst_audio_default_registry_mixer_filter() so the caller can decide which mixer elements should be kept and returned. When the mixer element is passed to the callback function, it is opened and in READY state. If you decide to keep the element, you need to set it back to NULL state yourself (unless you want to keep it opened of course).