Serve encoded audio data.

def _serve_individual_audio(self, request):
    """Serve encoded audio data."""
    tag = request.args.get('tag')
    run = request.args.get('run')
    index = int(request.args.get('index'))
    sample = int(request.args.get('sample', 0))
    events = self._filter_by_sample(self._multiplexer.Tensors(run, tag), sample)
    data = tensor_util.make_ndarray(events[index].tensor_proto)[sample, 0]
    mime_type = self._get_mime_type(run, tag)
    return http_util.Respond(request, data, mime_type)