lchiu7: I just discovered something interesting. According to the PS3 a one hour show on TV2 is about 2.4GB (and that's HD). Yet on TV3 using gbpvr a one hour is about 5G. I realise that TV3 sends down both a AAC and a DD 5.1 audio track but I wouldn't thought it would make that much difference. So is the difference down to 720p vs 1080i and the possible fact that TVNZ are compressing their stream much on the mux?
TV3 is 1080i, TV1 and TV2 are 720p. The 1080i broadcast simply uses more bandwidth.
From my observations TV1 seems to actually transmit at a slightly higher bitrate than TV2, recordings in GB-PVR are all bigger on TV1 than TV2.