Choppy playback is usually the result of a stream bitrate higher than client bandwidth, the throughput from Wowza to that client. Try a lower bitrate.
The “224.1.5.4:4000”, which is the stream name part of that url, is unusual but can work if it is an alias. An mpegts or multicast source is usually contained in a .stream file, a text file in the /content folder containing that udp url. For example a file /content/mpegts.stream that contained the udp url of the stream. Then you use mpegts.stream as the stream name instead of a URL. This is the basic mpeg-ts guide
The http url you show is not a complete playback URL that is supported by Wowza. For iOS playback it would have to be
http://xxx.xxx.xxx.xxx:1935/udp/224.1.5.4:4000/playlist.m3u8
or Flash HTTP
http://xxx.xxx.xxx.xxx:1935/udp/224.1.5.4:4000/manifest.f4m
Wowza’s output in this case is unicast, whether the source is multicast or not.
Richard