Those numbers you pulled out of the URL, the first number is the SitePublisherID - so is probably the same for all TVNZ stuff.
SitePublisherID = 963482467001
EDIT - digging around in the federatedVideo/BrightcovePlayer.swf, there may be several TVNZ publisher IDs.
TVNZ_PUBLISHER_IDS:Array = [963482464001, 963482467001, 945142951001, 742378304001, 1101631991001]
The other number is the SiteVideoID which seems to be very mysterious to generate.
SiteVideoID = 1461543813001
Here is a URL which will let you play any TVNZ video
Where you see 'videoPlayer=ref%3A' - just replace 4732141 with the episode ID (which can be found in the URL to any specific episode), or the XML files you identified earlier.
If you put that URL into RTMPDump it seems to extract an FLV file successfully, but not sure if that is helpful.
The BrightcoveBootloader.swf then passes a bunch of parameters through to
I think that BrightcovePlayer.swf is where it works out the RTMP URL. I've had a look through the decompiled code but haven't managed to spot anything too exciting.. it seems like it may have to set a special cookie or something which then allows the flash player to access the Brightcove API and get the RTMP URL.
FYI, if it helps anyone else investigating, this code will let you embed any video in an html file. Just change the number in the @videoPlayer field to change to a different video.
<object id="myPlayer" class="BrightcoveExperience">
<param name="bgcolor" value="#FFFFFF" />
<param name="playerID" value="1257248093001" />
<param name="playerKey" value="AQ~~,AAAA4FQHurk~,l-y-mylVvQmMeQArl3N6WrFttyxCZNYX" />
<param name="isVid" value="true" />
<param name="overrideAds" value="true" />
<param value="ref:4732141" name="@videoPlayer" />
There are some other calls going off to Tubemogul with Cookies and JSON but not sure if they are important or just for some sort of metrics.