HD AV said:
Dude, you have seriously lost it. There is no compression with Blu Ray, the bitrates are much higher providing much higher quality and detail that blows away MPEG2 broadcast TV. And most, not all, 1080P TVs do not properly implement 3:2 pulldown, which is not necessary with one that will accept 1080P/24. I think you may want to have your glasses checked.
Thanks for the free consultation, but maybe later. Actually, you may want to have your facts checked. And I can help you with that:
1) All HD is compressed. That includes Blu, which uses the very same MPEG-4compression scheme that DTV uses. Since uncompressed HD has a bit rate of about 1.485 Gb/s, that would mean that a 30 GB disc could only hold less than 3 minutes of video, were Blu-Ray uncompressed. So you are grossly misinformed on that count. And, you can look that up. Most HD is compressed in the very act of acquisition.
2) "Detail" refers to how sharp the picture is, which is directly tied to resolution. All else held equal (focus, lens quality, imager quality, etc.), 1080p or 1080i resolution is exactly the same regardless of what medium it might be delivered to you in, which means the detail in 1080i OTA TV is precisely the same as that in Blu-Ray. If you are seeing more "detail", then you are simply fooling yourself. There isn't any more to see. Also, resolution and bit rate are two completely different things that typically do not affect each other. There are some low-bit delivery schemes that effectively lower resolution, but that is not the case in OTA and cable, and thankfully is no longer the case for DBS.
3) While that means that higher bit rates do not provide higher detail (which as we have established is instead a function of resolution), higher bit rates also do not necessarily provide higher quality in any other way. I know that's a hard one to swallow, and an inviting conclusion that would be very easy to jump to. In a case where there are plenty of bits to go around, such as in a OTA broadcast at 14.5 Mb/s, increasing the bit rate will not buy you any increase in quality whatsover. Shocking, (to those who are misinformed or who have not been able to resist jumping to that conclusion) but completely true. Only when lower compression techniques use trade-offs that compromise quality to prevent equivalent artifacting at those much-lower bit rates, is there necessarily any reduction in quality. It is a common, yet highly flawed misconception, that raising bit rates or having a higher bit rate on one medium as compared to another, will automagically yield better quality. As someone who gets paid handsomely to work with compression algorithms on a daily basis, I think I can safely say that it just doesn't work that way.
That said, I will agree that some HD delivered by bit-starved systems will not track motion with the same level of artifacting as will HD delivered without equivalent bit starving. And true, some OTA stations do that. In that case, "Transformers" from an ABC station with two sub channels may not look quite as good during action sequences as a Blu-Ray copy will. But the difference in the action sequences may not be that significant even for the most bit-starved frames, and 99% of all frames with motion will look nearly indistinguishably the same in either case, and all frames with low or no motion will look identical in either case. But then that is not the hair-splitting argument I was speaking of, and is somewhat beyond the scope of the thread and the discussion we all were having.
4) Pulldown is not all that difficult to do. Especially with digital circuitry, which makes storing and repeating frames pretty simple, and is exactly what pulldown requires. If a display manufacturer can't do pulldown properly, then they have no business even being in the business.
Not only that, but for the case I posted about, which is 1080p24 delivered in a 1080i30 format (well, 29.97 if you do want to split hairs) It is not the display that does the pulldown, it is the decoder. The ability of the decoder to do pulldown is a part of the ATSC spec, and a part of "film mode" which is the mode invoked when 1080p24 content is sent. Every ATSC decoder conforms to that spec, and includes this ability. All your TV has to do is to accept the 1080i30 content that is reconstituted WITHIN the last stage of the decoder, and display it progressively as 1080p, which is what the set is not only designed to do, but is exactly what it does with all content (displays it as 1080p60). And that means it does exactly the same thing when fed 1080p24 directly from Blu--it displays it as 1080p60. And that would imply pulldown done in the display, not the decoder. If, as you say, some sets might not do pulldown properly, then it would actually be the Blu content that is at risk, not content that was already pulled during decoding via ATSC.
Of course it is important to distinguish 1080p60 as a display format from 1080p60 as an acquisition format, which I mention only because most folks confuse the two and incorrectly impart the benefits of the acquisition format to the display format. For those who only could get into community college, I can break that down: 1080p60 acquisition format = good. 1080p60 display format = possibly not so good, depending on the original content.
For acquisition, it implies that there are 60
unique 1920x1080 fields recorded progressively each second, with no interlace error. As a display format, it only implies that the raster displays 60 1920x1080 fields progressively each second. It
does not imply that the fields are unique (which they won't be with pulldown)
or that they will not include interlace error (which they will if acquired as interlaced content). Bottom line, 1080p60 as an acquisition format is significantly better than other formats due to more frames and no interlace error(except for 720p) while a 1080p display is somewhat better than a 768 or 720 display, only for completely different reasons, and not for the reasons enjoyed by the 1080p60 acquisition format.
But then regardless of all of that, if you are thick enough to actually buy a set that doesn't do reinterlace or pulldown properly, (after all, it
IS 2008), then I probably would have a hard time drumming up sympathy for you.