That link does play natively for me, although it takes a while to get going.
I used MC > File > Open URL... with this URL:
RTMPE://live-geo.mediaworks.co.nz/live/morefmwellington_64kbps
To open the RTMP stream takes around 5 seconds. Then, it takes LAV Splitter / Decoder a while to read enough data to let playback begin. Sometimes streams are a challenge for a parser because they only provide data at a real-time data rate, so reading ahead something that seems conservative like 1MB could take a long time on a low bitrate realtime stream.
I'll send this thread to nevcairiel (author of LAV) just to see if he has any thoughts on the startup time.
Here's the playback graph:
Filter Graph Info:
Filter 'JRiver Audio Renderer'
CLSID: {A4002F8E-510F-442C-8AD3-F9C7B23FB394}
Host:
Input Pin 'In'
Connected to pin 'Output' of filter 'LAV Audio Decoder (auto-configured)'
Major type MEDIATYPE_Audio Sub type MEDIASUBTYPE_IEEE_FLOAT, Format type FORMAT_WaveFormatEx
Filter 'LAV Audio Decoder (auto-configured)'
CLSID: {E8E73B6B-4CB3-44A4-BE99-4F7BCB96E491}
Host: C:\Users\Main\AppData\Roaming\J River\Media Center 18\Plugins\lav\LAVAudio.ax
Input Pin 'Input'
Connected to pin 'Output' of filter 'JRiver Audio Monitor'
Major type MEDIATYPE_Audio Sub type Unknown GUID Name: {53544441-0000-0010-8000-00AA00389B71}, Format type FORMAT_WaveFormatEx
Output Pin 'Output'
Connected to pin 'In' of filter 'JRiver Audio Renderer'
Major type MEDIATYPE_Audio Sub type MEDIASUBTYPE_IEEE_FLOAT, Format type FORMAT_WaveFormatEx
Filter 'JRiver Audio Monitor'
CLSID: {A4207487-E7D8-406B-9882-B66370DE2492}
Host:
Input Pin 'Input'
Connected to pin 'Audio' of filter 'LAV Splitter (auto-configured)'
Major type MEDIATYPE_Audio Sub type Unknown GUID Name: {53544441-0000-0010-8000-00AA00389B71}, Format type FORMAT_WaveFormatEx
Output Pin 'Output'
Connected to pin 'Input' of filter 'LAV Audio Decoder (auto-configured)'
Major type MEDIATYPE_Audio Sub type Unknown GUID Name: {53544441-0000-0010-8000-00AA00389B71}, Format type FORMAT_WaveFormatEx
Filter 'LAV Splitter (auto-configured)'
CLSID: {171252A0-8820-4AFE-9DF8-5C92B2D66B04}
Host: c:\program files (x86)\lav filters\lavsplitter.ax
Input Pin 'Input'
Connected to pin 'Output' of filter 'JRiver Reader Source Filter'
Major type TIME_FORMAT_NONE Sub type TIME_FORMAT_NONE, Format type TIME_FORMAT_NONE
Output Pin 'Audio'
Connected to pin 'Input' of filter 'JRiver Audio Monitor'
Major type MEDIATYPE_Audio Sub type Unknown GUID Name: {53544441-0000-0010-8000-00AA00389B71}, Format type FORMAT_WaveFormatEx
Filter 'JRiver Reader Source Filter'
CLSID: {25FF55CB-CE77-4F64-A9D2-CA89BA57E8A5}
Host:
Output Pin 'Output'
Connected to pin 'Input' of filter 'LAV Splitter (auto-configured)'
Major type TIME_FORMAT_NONE Sub type TIME_FORMAT_NONE, Format type TIME_FORMAT_NONE