Logstash Pipelines doesn't work when logs come from Filebeat

Hi,
I've built a pipeline.conf in Logstash that works when the input is a path file (so without using filebeat shipping).
But when I just modify the input, so by replacing path input with beats port 5044 (Filebeat),
all the log files harvested with Filebeat reach Elasticsearch through Logstash. But the pipeline didn't make its job because the logs are not transformed, so as the same result as setting elasticsearch output instead of logstash...
My Filebeat output is set on Logstash so I don't understand why my pipeline don't affect on the logs harvested with Filebeat.
Help please :''''(