def get_switch_elements(self, pipeline):
raise errors.NotImplementedError('subclasses should implement '
'get_switch_elements')
def get_muxer_string(self, properties):
"""
Return a gst-parse description of the muxer, which
must be named 'muxer'
"""
raise errors.NotImplementedError("Implement in a subclass")
def get_logical_feeds(self):
raise errors.NotImplementedError('subclasses should implement '
'get_logical_feeds')