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Discussion Starter · #1 ·
Is it just my set-up, or does HBO-HD not look thaaaaat much better than 480p (progressive scan) DVD ?...as compared to HDNet which I suppose is all 1080i video-based...just SPECTACULAR, awesome, sharp, vivid, etc.


Perhaps the HBO-HD is mostly film??? which may not be as sharp as 1080i-original-video-based??? I am just surmising.


Any comments/advice/observations ?
 

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Agree completely. Film based HD PQ varies significantly. But hey, better than 480p any day.
 

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I think the eyes and ears both adapt readily to images and sounds of varying quality. While it allows us to cope with such assaults as AM radio and VHS EP on a projection TV, it also allows us to quickly accept high quality as nothing more than our due.


Most of the time, when watching even the highest-quality video image, it quickly settles down to a "that looks OK." A High-definition movie seems to look no better than a DVD, or a DVD no better than a tape. An A-B comparison usually settles it. :)
 

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Both HBO and Showtime HD are deliberately "crippled" to an extent by using only ~75% of the available 19.4 Mb/sec bandwidth. That's really not enough to do justice to 1080i. Others have speculated they also soften the image before encoding to make the overcompression less noticeable. Discovery HD, CBS, HDNET, etc. are more likely to use higher bandwidth. Plus all the film vs video differences that have been mentioned here before.


Joe
 

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Discussion Starter · #5 ·
Yea, I'm noticing a significant difference in P.Q. between HDNet and the HBO-HD. HBO-HD sometimes looks a little grainy compared to the pristine razor-sharp HDNet. But the aforementioned HBO-HD is significantly better than the non-HD HBO channels...which are a little better than regular NTSC programming !:(
 

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it is the rare dvd that looks as good as most hbo hd, to our eyes here.


tho I often find that I get use to hd, and don't think it is so great. with both hbo and hd video sources, that is, till I see a dvd or nstc then I realize what a dope I was being :D..
 

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Quote:
Originally posted by jamoka
Both HBO and Showtime HD are deliberately "crippled" to an extent by using only ~75% of the available 19.4 Mb/sec bandwidth. That's really not enough to do justice to 1080i. Others have speculated they also soften the image before encoding to make the overcompression less noticeable. Discovery HD, CBS, HDNET, etc. are more likely to use higher bandwidth. Plus all the film vs video differences that have been mentioned here before.


Joe
How do we know this? The available data rate on on a directv transponder is about 27 Mbit (or about 30 Mbit if 5/6 FEC is used). The 19.4 Mbit rate you refer to is the terrestrial 8VSB ATSC rate and doesn't apply here. Are you thinking of too aggressive high-frequency roll-off to prevent flicker and moire effects. That has the effect of reducing resolution, and thus bandwidth requirements. Also, film is going to have lower bandwidth requirements because of the lower frame rate.


Ernie/NE6D
 

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"How do we know this?"


We know this because we have measured it many times.


"Are you thinking of too aggressive high-frequency roll-off to prevent flicker and moire effects"


No. Just the bandwidth measurement I posted.


"Also, film is going to have lower bandwidth requirements because of the lower frame rate."


Incorrect. And, anticipating your next question, because we have measured it many times.:)


Joe
 

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I think he referring to the fact that hd tuner cards list the rate of teh programs from teh hd movie channels as being at about 14.2.. which is less in comparison to an ota source. And thus have more compression.
 

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Well first off of course HDNet looks better since we're talking video vs. film. Two entirely different mediums. This has been discussed 1,000 times before. However, HBO can look spectacular depending on the transfer. The proof of this is when synching up D-Theater tapes @ 28 mps vs. HBO with the same material. I've done this as have others with the JVC HD VCR and find VERY little difference in PQ. You have to try this yourself to convince yourself that HBO movies are NOT crippled unless the transfer is particularly bad (which does happen). I haven't seen anyone who owns the JVC deck try this experiment and report seeing a big diffference.
 

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Ken,


13 - 14 Mb/sec MPEG2 is not adequate for 1920 X 1080 video with significant motion. You are lucky if you don't notice them on your system, but the motion artifacts are there, believe me. MPEG2 video gets very "blocky" when overcompressed like that. With these motion scenes, there is a significant and noticeable difference between the same 1080i (or 1080p) video encoded at 13 -14 Mb/sec vs 18 -23 Mb/sec rate you would expect from OTA, Dtheater, etc.


Why any particular Dtheater transfer would look no better than the HBO HD broadcast, I don't know.


Joe
 

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Quote:
Originally posted by jamoka


"Also, film is going to have lower bandwidth requirements because of the lower frame rate."


Incorrect. And, anticipating your next question, because we have measured it many times.:)


Joe
Actually you didn't anticipate my next question. It is: what is the test setup to make these measurements?


Ernie
 

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Quote:
Originally posted by Ken Ross
Well first off of course HDNet looks better since we're talking video vs. film.
Video looks better than film - that's a good one LOL.
 

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Quote:
Originally posted by tin ear
Video looks better than film - that's a good one LOL.
The true HD video that I've seen certainly looks far better than any film telecine that I've seen.


Video - all available framerate (60i/p), all available resolution, limited color gamut

Film - 24 fps (
 

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 TV TECH ARTICLE


... Using a custom encoding and uplinking system on each HD truck, the game feed is back-hauled to HDNet’s broadcast operations center in Denver, which in turn transmits the feed – in 19.394 MPEG-2 DVB-ASI with AC-3 audio – to DirecTV’s HD Operations Center in Los Angeles, which distributes it via satellite. ...


Quote:
Originally posted by ernie
How do we know this? The available data rate on on a directv transponder is about 27 Mbit (or about 30 Mbit if 5/6 FEC is used). The 19.4 Mbit rate you refer to is the terrestrial 8VSB ATSC rate and doesn't apply here. Are you thinking of too aggressive high-frequency roll-off to prevent flicker and moire effects. That has the effect of reducing resolution, and thus bandwidth requirements. Also, film is going to have lower bandwidth requirements because of the lower frame rate.


Ernie/NE6D
 

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Totally subjective, as are most references I see to"PQ".

Quote:
Originally posted by tin ear
Video looks better than film - that's a good one LOL.
 

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Is it not the case that HBO horizontal filtering to ~1200-1440 is a part of the problem? In addition to (allowing) lower rates?


Just a question...


:D

Quote:
Originally posted by WOLVERNOLE
Yea, I'm noticing a significant difference in P.Q. between HDNet and the HBO-HD. HBO-HD sometimes looks a little grainy compared to the pristine razor-sharp HDNet. But the aforementioned HBO-HD is significantly better than the non-HD HBO channels...which are a little better than regular NTSC programming !:(
 

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Quote:
Video looks better than film - that's a good one LOL.
'Better' isn't a good word to describe it, but we know what he means. It looks hugely more realistic and vibrant. I'm not saying that film looks bad, since it has it's positive points. But if you put any person who isn't a knowledgeable videophile who understands the differences between film and video in front a film projection and an HD video based projection, and they would all chose the HD video presentation, because the advantages over SD content is so obvious to see.


Almost anyone among even us videoscentic who want to show off our HD systems are likely to put in something like the D-Theater demo disc or recordings of HDNet video based content, for those same reasons. I always show the D-Theater demo tape, which is all video based and which completely blows away anything else out there as demo material.


Most average folks out there could care less about the differences between film and video, and the appeal of film to film lovers. They will all gravitate towards the HD-Video based content. In fact, if you help a non-technical person set up an HD system of their own, they are very likely to complain if the first thing you demo to them is something film based. They just don't see the increased detail as particularly significant. They want to see HD-Video based content with it's vivid image.


To me, this says that film is doomed, not just because it will pretty quickly become far less convenient than high resolution video shooting (probably at higher than HD resolution for the original master copies), but because HD has made video competitive with film in terms of resolution (whereas before it was always high resolution film vs. low resolution video), and people are going to want more of it.


Though film has it's appeal, I'm not at all convinced that it was ever all that superior other than in resolution. Yes it has some technical advantages still of contrast range I guess, but that's not something that you can sell, or even really point out very well, to what will become the average HD consumer as we move fully into the HD world. Its only due to long conditioning that we see the film look as artsy and the video look as cheesy. But I think that will fall away quickly enough now that video can compete on resolution.


It may still be manipulated to some degree or another. At first they'll try to make it look like film, but I bet that that recedes over time, moving more and more towards the 'realistic' look of video. When you think about it, we buy all of this equipment to get a more realistic image, but we use a medium incapable of providing a really realistic image. If you think about it outside of the decades of film indoctrination, it doesn't make a lot of sense.
 

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To follow Dean's point, I think I am correct in saying X-Men 2 was produced using HD cameras. This seems to suggest Hollywood is at least considering using video over film. Certainly, at least one person found there to be an advantage.
 

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Any idea why motion pictures are still shot at 24fps? I assume that it was done in Edison's day to save film, or because it was difficult to build cameras and projectors that worked at a higher speed.


But today, we don't have that limitation. And while we are certainly used to the "look" of 24fps, I can't imagine that a higher frame rate wouldn't be more realistic. Black and white has a certain desirable look too, but not many films are still shot that way.
 
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