pneu Posted October 12, 2008 Posted October 12, 2008 I am interested to know what people think of 9HD's picture quality for high definition programs compared to what 7HD/10HD is putting out. Personally I find it notably softer than 7HD/10HD and have read similar comments from a few other users on this forum. There have also been numerous posts on the contrary. In theory there should not be much difference as all 3 channels are using the same 1080i format. I feel that screen size plays a big part in this as I could not see much difference on a 42" screen. Now that I have moved to a 50" screen I notice 9HD is markedly softer and less detailed than 7HD/10HD. What do you guys think?
boric Posted October 12, 2008 Posted October 12, 2008 (edited) In theory there should not be much difference as all 3 channels are using the same 1080i format. As an extremely simplistic theory, that would be correct. But it's too simplistic and wrong. Resolution (1080i) doesn't say anything about quality. As you've noticed Nine's 1080i does not equal 7 or Ten's 1080i, bitrate has a lot to do with it and the quality of encoders and source material etc etc. But yes, Nine's HD is poor compared to the other two. It's noticeably worse on my 40" screen. Edited October 12, 2008 by boric
davmel Posted October 12, 2008 Posted October 12, 2008 In theory there should not be much difference as all 3 channels are using the same 1080i format. The vertical resolution might be the same but the horizontal resolution is different which contributes to the loss of detail: 7HD: 1920x1080i @ 14.5Mbps 9HD: 1440x1080i @ 12.5Mbps 10HD: 1920x1080i @ 16.5Mbps So not only is the bitrate less but the resolution is only 75% of the other two. Mind you the necessary bitrate is tied to the resolution. If you only had 75% of the resolution you only need 75% of the bitrate, so in terms of bitrate/resolution 9HD is actually better allocated with bitrate than the others. One can only guess that the reason they haven't upped the resolution and bitrate to full 1920x1080i yet like the other two have in the past year is due to inferior encoders or they are deliberately leaving space in their multiplex for a 3rd channel.
ozasis Posted October 12, 2008 Posted October 12, 2008 Looks pretty good here in Adelaide though... I think we're blessed with a higher birate?
pneu Posted October 12, 2008 Author Posted October 12, 2008 Looks pretty good here in Adelaide though... I think we're blessed with a higher birate? I'm in Adelaide too and believe they are using 1920x1080i at a reasonably healthy bitrate. However the picture quality is still miles behind the other two. I'm not sure the horizontal resolution argument holds up as vertical resolution is the most important and I've compared 1440 vs 1920 and the difference is almost completely unnoticeable.
davmel Posted October 12, 2008 Posted October 12, 2008 I'm not sure the horizontal resolution argument holds up as vertical resolution is the most important and I've compared 1440 vs 1920 and the difference is almost completely unnoticeable. Really? Are your eyeballs more sensitive in the vertical plane over the horizontal plane? ;-)
pneu Posted October 12, 2008 Author Posted October 12, 2008 Really? Are your eyeballs more sensitive in the vertical plane over the horizontal plane? ;-) Yes it's true, horizontal resolution is not as important. I believe it's the reason why anamorphic widescreen is used, the same reason 42" plasmas can get away with having rectangular pixels (1024x768).
goosagichy2135 Posted October 13, 2008 Posted October 13, 2008 in perth win took 9hd from 15mbs 1920x1080 +dd5.1 to 14.5mbs 1440x1080 dd2.0
Neon Kitten Posted October 14, 2008 Posted October 14, 2008 While Nine's HD quality is always inferior to the other two commercials, with decent source material it can look okay. Fringe looks pretty good, for example. But Studio 60 last week was such a blurry mess I'm not exaggerating to say that my 350MB Xvid of the episode actually looked better! They need a decent encoder, I suspect. Or someone who knows how to configure one.
pneu Posted October 14, 2008 Author Posted October 14, 2008 While Nine's HD quality is always inferior to the other two commercials, with decent source material it can look okay. Yes, with very good source material it looks "okay" , but it still lacks that really ultra-crisp* look that I see on 7 and 10. What do you think of the 9HD loop? I still think it's softer than it should be. *not to be confused with over-sharpened images which 7 are sometimes guilty of
Neon Kitten Posted October 14, 2008 Posted October 14, 2008 What do you think of the 9HD loop? I still think it's softer than it should be. There's a 9HD loop? (I'm in Melbourne, and have never seen one broadcast)
pneu Posted October 15, 2008 Author Posted October 15, 2008 ah there mustn't be one in melbourne. Here in Adelaide they play a demo loop from about 12pm-4:30pm every day. I've heard that 7 has a demo loop too but we don't get that, however they played a few minutes of it the other night as a filler and it looked WAY better than 9's loop (although it was guilty of a bit of over sharpening).
digitalj Posted October 17, 2008 Posted October 17, 2008 Yes, with very good source material it looks "okay" , but it still lacks that really ultra-crisp* look that I see on 7 and 10.What do you think of the 9HD loop? I still think it's softer than it should be. *not to be confused with over-sharpened images which 7 are sometimes guilty of hmm, 7 has 1 SD Channel and 1 HD Channel, 9 has 1 SD Channel a VPG and 1 HD Channel, TEN has 1 SD and a HD Channel. 7 HD and TEN HD are good, 9HD isn't as good, I wonder why? Get rid of that darn VPG channel 9
pneu Posted October 17, 2008 Author Posted October 17, 2008 We dont have a VPG in Adelaide and the bit rate is higher too (something like 16mbps) , so it can't be that. It's got to be their equipment, something in the chain just isnt doing a good enough job.
digitalj Posted October 17, 2008 Posted October 17, 2008 We dont have a VPG in Adelaide and the bit rate is higher too (something like 16mbps) , so it can't be that. It's got to be their equipment, something in the chain just isnt doing a good enough job. well if that's the case, the only difference I can really see is that 9HD is 1440x1080i, because 7HD and TEN HD are 1920x1080i, but then again, because they all have about the same bitrate, then 9HD should look better as there are more bits per pixel, i.e. 7HD and Ten HD would have about 0.32 bits/pixel, while 9HD would have about0.43 bits/pixel. So this draws me to a conclusion that it is due to how 9's HD Encoder is configured* and how efficient the encoder is *this includes de-interlacing for rescaling then re-interlacing and lots of other little things.
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