Cannot use the plugin with fluentd v1.4

[chbndrhnns]

When I follow the instructions to use the plugin with fluentd v1.4, I get this error message:

fluentd_1        | 2019-05-23 12:06:22 +0000 [error]: config error file="/fluentd/etc/fluent.conf" error_class=Fluent::ConfigError error="Unknown filter plugin 'record_splitter'. Run 'gem search -rd fluent-plugin' to find plugins"
docker-elk_fluentd_1 exited with code 1

Is it maybe related to fluent/fluentd#1826?