1080p: HD Luxury or Necessity
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CycloneGT, you should add " @ greater then 30 fps" to being "too bandwidth hungry to even consider at this time".
This would be ideal for 99% of the movie channels. (24 or 30p)
Since a progressive signal is supposed to compress better (it would make sense), then it would be easier to send a 1080p30 signal instead of a 1080i60 signal. The problem lies within the STB to do the job right then. Very easy to interlace a progressive signal, hard to do the opposite.
But "at this time" is quite right.
This would be ideal for 99% of the movie channels. (24 or 30p)
Since a progressive signal is supposed to compress better (it would make sense), then it would be easier to send a 1080p30 signal instead of a 1080i60 signal. The problem lies within the STB to do the job right then. Very easy to interlace a progressive signal, hard to do the opposite.
But "at this time" is quite right.
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Could you get equal compression to progressive with interlaced if you kept the even and odd frames separate when compressing?
| [Since a progressive signal is supposed to compress better (it would make sense), then it would be easier to send a 1080p30 signal instead of a 1080i60 signal. The problem lies within the STB to do the job right then. Very easy to interlace a progressive signal, hard to do the opposite. |
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Did anyone else notice a few glaring missing aspects in this article?
1. No mention of update rate but since they were comparing 1080p to 720p we'll just have to assume 60 frames/sec. In this case the extra bandwidth is needed and does not follow present ATSC standards.
2. 1080p 24fps does not require more bandwidth. It can be argued that 1080p 24fps/ requires less bandwidth than 480i DVD's sold today. No new technology needed.
3. Displays can be made (perhaps already are - if so they are probably out of my price range
) to deinterlace with 3-2 pull down present day 1080i HD content from film based material and fully recover a 1080p 24fps picture. This process is no different than with todays 480i DVD deinterlacers for film based material. You just happen to get 600 more vertical lines resolution - thats all . Again no new technology other than the display needed. I can argue that watching film material from any HD source today has a standard TV to Progressive Scan/3-2 Pulldown potential increment in quality just by making a better display.
4. I believe the ATSC standard has in it's list of resolutions 1080p/24fps. So the infrastructure is already in place to deliver 1080p film content. Again no new technlogy needed.
I guess that's a few things missed in the article. Not many I guess.
1. No mention of update rate but since they were comparing 1080p to 720p we'll just have to assume 60 frames/sec. In this case the extra bandwidth is needed and does not follow present ATSC standards.
2. 1080p 24fps does not require more bandwidth. It can be argued that 1080p 24fps/ requires less bandwidth than 480i DVD's sold today. No new technology needed.
3. Displays can be made (perhaps already are - if so they are probably out of my price range
) to deinterlace with 3-2 pull down present day 1080i HD content from film based material and fully recover a 1080p 24fps picture. This process is no different than with todays 480i DVD deinterlacers for film based material. You just happen to get 600 more vertical lines resolution - thats all . Again no new technology other than the display needed. I can argue that watching film material from any HD source today has a standard TV to Progressive Scan/3-2 Pulldown potential increment in quality just by making a better display.4. I believe the ATSC standard has in it's list of resolutions 1080p/24fps. So the infrastructure is already in place to deliver 1080p film content. Again no new technlogy needed.
I guess that's a few things missed in the article. Not many I guess
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Just regurgitating what I've heard. I suppose if you captured at 60p it might aid the compression, but because 60i (sourced at 60i and not 24/30p) isn't merely 30p split into fields I'm sure it causes complications with the encoding blocks.
edit: I also believe there are no standard resolutions in the ATSC spec, just suggested ones of which 1080p @ 30 and 24 is included.
| Originally posted by shawn12341234 Could you get equal compression to progressive with interlaced if you kept the even and odd frames separate when compressing? |
edit: I also believe there are no standard resolutions in the ATSC spec, just suggested ones of which 1080p @ 30 and 24 is included.
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Except for the extra filtering done because most folks will be viewing it in interlaced format, we are getting 1080p now, just like DVD is delivering 480p now. All you need is the hardware to deinterlace it. Many of us are using boxes like the Key Digital HD Leeza to deinterlace HD already, so we already have 1080p, though in my case I'm also having it then downscale it to 720p since that's the optimum for my particular projector.
So for film material, 1080p is already available for all intents and purposes. Yes, it would be nice to have unfiltered content, but believe me, deinterlaced film content looks damn good already. There was always hope that the HD-DVD would be designed to provide unfiltered content, and that the player would do the filtering on the fly, so that those of us doing the dinterlacing wouldn't pay that price, but I doubt it'll happen.
Even on video based material, it's a huge advantage. When I watched the D-Theater demo tape (which has very high quality, high bit rate material on it) on my system before, it looked great, but there are some interlacing artifact tourture scenes, such as the sloped Japanese tilled temple roofs. Now they only have the slightest amount of twittering left and it looks infinitely better.
So for film material, 1080p is already available for all intents and purposes. Yes, it would be nice to have unfiltered content, but believe me, deinterlaced film content looks damn good already. There was always hope that the HD-DVD would be designed to provide unfiltered content, and that the player would do the filtering on the fly, so that those of us doing the dinterlacing wouldn't pay that price, but I doubt it'll happen.
Even on video based material, it's a huge advantage. When I watched the D-Theater demo tape (which has very high quality, high bit rate material on it) on my system before, it looked great, but there are some interlacing artifact tourture scenes, such as the sloped Japanese tilled temple roofs. Now they only have the slightest amount of twittering left and it looks infinitely better.
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How do you figure that?
1080p 24fps = 1080*1920*24=49,766,400 pixels per second
480i 60 fields/sec = 720*480*30=10,368,000 pixels per second
Thats still 5 times the bandwidth by my math. If I am wrong, somebody please explain it to me.
I think from reading that article that they are implying 1080p and 60 full frames per second based on the fact that they said 3Gbps vs the 1.5 Gbps used for today's 1080i and 720p. And they said in the article that 19.4 Mbps is not enough bandwidth for 1080p60 unless you used MPEG-4 or WM9 for compression.
I do agree that 1080p 24 or 30 would be great for todays movie channels like HBO and such.
| Originally posted by hdtv_moron 2. 1080p 24fps does not require more bandwidth. It can be argued that 1080p 24fps/ requires less bandwidth than 480i DVD's sold today. No new technology needed. |
1080p 24fps = 1080*1920*24=49,766,400 pixels per second
480i 60 fields/sec = 720*480*30=10,368,000 pixels per second
Thats still 5 times the bandwidth by my math. If I am wrong, somebody please explain it to me.
I think from reading that article that they are implying 1080p and 60 full frames per second based on the fact that they said 3Gbps vs the 1.5 Gbps used for today's 1080i and 720p. And they said in the article that 19.4 Mbps is not enough bandwidth for 1080p60 unless you used MPEG-4 or WM9 for compression.
I do agree that 1080p 24 or 30 would be great for todays movie channels like HBO and such.
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Why wait - the HBO HD sources that I have uncompressed have 24 fps progressive structure. So does Sho.
I imagine that the streams contain pulldown flags to make 29.97 1080i, much like the flags in progressively encoded DVDs.
We just need a STB that will allow the 24 fps progressive output.
Cheers!
DAve.
| Originally posted by D-rock0030 I do agree that 1080p 24 or 30 would be great for todays movie channels like HBO and such. |
I imagine that the streams contain pulldown flags to make 29.97 1080i, much like the flags in progressively encoded DVDs.
We just need a STB that will allow the 24 fps progressive output.
Cheers!
DAve.
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Another member on this board (trbarry??) convincingly showed a while back that the present MPEG2 standard + the maximum bitrate DVD's are capable of is plenty enough for encoding 1080p 24fps if the DVD is in a "superbit" like format. I reread my post and clearly I worded what I was trying to say wrong. Sorry about that.
Although if 19.2mbs is good enough for 1080i-60 fields/s it is plenty good enough for 1080p-24 frames/s. (1080*1920*30
Again 1080p 24fps is here today and now with film based HD material. All that is necessary to see it is a 1080p display and a 1080i->1080p deinterlacer with 3-2 pulldown (if it is not built into the display). Of course quality would be better if the MPEG2 encoding was done progressively vs interlaced. Delivering the content in a source form of 1080 24fps would be the best.
Does a 1920x1080 DLP chip or LCD panel (or LCOS, etc. etc. ) even exist? Until then a reasonably priced display technology capable of 1080p 24fps that can actually show all the pixels doesn't exist.
| Originally posted by D-rock0030 How do you figure that? 1080p 24fps = 1080*1920*24=49,766,400 pixels per second 480i 60 fields/sec = 720*480*30=10,368,000 pixels per second Thats still 5 times the bandwidth by my math. If I am wrong, somebody please explain it to me. I think from reading that article that they are implying 1080p and 60 full frames per second based on the fact that they said 3Gbps vs the 1.5 Gbps used for today's 1080i and 720p. And they said in the article that 19.4 Mbps is not enough bandwidth for 1080p60 unless you used MPEG-4 or WM9 for compression. I do agree that 1080p 24 or 30 would be great for todays movie channels like HBO and such. |
Although if 19.2mbs is good enough for 1080i-60 fields/s it is plenty good enough for 1080p-24 frames/s. (1080*1920*30
Again 1080p 24fps is here today and now with film based HD material. All that is necessary to see it is a 1080p display and a 1080i->1080p deinterlacer with 3-2 pulldown (if it is not built into the display). Of course quality would be better if the MPEG2 encoding was done progressively vs interlaced. Delivering the content in a source form of 1080 24fps would be the best.
Does a 1920x1080 DLP chip or LCD panel (or LCOS, etc. etc. ) even exist? Until then a reasonably priced display technology capable of 1080p 24fps that can actually show all the pixels doesn't exist.
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These things are under development (DLP, LCoS, LCD and Plasma) at 1080p. There were examples of all at CES this year.
They might not be there now, but I believe that 2005 will be big for 1080 from all fronts. And 2005 is not that far in the future!
Cheers!
DAve.
| Originally posted by hdtv_moron Does a 1920x1080 DLP chip or LCD panel (or LCOS, etc. etc. ) even exist? Until then a reasonably priced display technology capable of 1080p 24fps that can actually show all the pixels doesn't exist. |
They might not be there now, but I believe that 2005 will be big for 1080 from all fronts. And 2005 is not that far in the future!
Cheers!
DAve.
At this time, it seems to me that all types of HDTV are still regarded as a luxury by most Americans. And while many in the US might consider tv itself a necessity, it's still regarded as a luxury by most of the world's citizens.
As for 1080p being here in 2005, exactly which networks and what stations do you think will be scrapping their 1080i or 720p equipment to bring you shows in 1080p? I'm still waiting for some other channels besides HDNet, DiscoveryHD, and PBSHD to provide all HD programming in the current formats.
I guess ESPN will probably be the first to adapt 1080p. That will enable them to continue broadcasting most of their games in SD, because "there aren't enough trucks equipped with 1080p yet."
As for 1080p being here in 2005, exactly which networks and what stations do you think will be scrapping their 1080i or 720p equipment to bring you shows in 1080p? I'm still waiting for some other channels besides HDNet, DiscoveryHD, and PBSHD to provide all HD programming in the current formats.
I guess ESPN will probably be the first to adapt 1080p. That will enable them to continue broadcasting most of their games in SD, because "there aren't enough trucks equipped with 1080p yet."
I guess us europeans are just envious that you have hd tv at all
Anyways, as the world never once could agree on a consumer standard, and europe is uasually later than japan and the us, chances are that we may benefit from improvements (like pal vs ntsc)
interlacing IS a problem for compression, esp real interlaced material.
The only certainty of future display devices is that their specifications will improve. As such, having a flexible format that capture as much as possible of the source material (commonly 24fps film) makes most sense.
As crt screens will probably disappear over time, I find it strange that any interlacing standards are being implemented. Why not choose a format that is easiest to compress and display?
K
Anyways, as the world never once could agree on a consumer standard, and europe is uasually later than japan and the us, chances are that we may benefit from improvements (like pal vs ntsc)
interlacing IS a problem for compression, esp real interlaced material.
The only certainty of future display devices is that their specifications will improve. As such, having a flexible format that capture as much as possible of the source material (commonly 24fps film) makes most sense.
As crt screens will probably disappear over time, I find it strange that any interlacing standards are being implemented. Why not choose a format that is easiest to compress and display?
K
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Interlacing is only partially a legacy of scanning CRT's. It is also a good compromise for saving storage and bandwidth if you believe, as I do, that moving pictures at 24 or 30 frames / second are just too jerky and unrealistic.
While 1080i doesn't really give you a full 60 frames / second it does at least hide the jerkiness reported with progressive 30 FPS cameras like the newer JVC HD-cam.
We have all managed to grow accustomed to 24 fps movies but they really do not make a very realistic picture with things move much. They are just a compromise for what we could afford to do when movies were first invented.
Mostly to make them acceptable Hollywood has to use narrow depth of field, out of focus panning backgrounds, and slower shutter speeds to create motion blur.
Of course most in Hollywood are appalled at the idea of 60 (or 72) FPS movies and claim they would be too expensive and would have too much of that video look. I guess it's just a matter of taste.
But 1080p @ 60 will probably better match the new fixed pixel displays that will become the standard. And there is already enough storage space on blue laser DVD's with modern codecs to be able encode video that way.
I don't actually expect Hollywood to rapidly embrace this idea but I think it is inevitable with the next generation of movie makers since the displays will be here and people will be able to easily compare. So as the price of "filming" to hard drive continues to drop toward zero we should begin to see some of this within another couple revolutions of the Moore's Law crank. Heck, commodity disk drive storage is already less than 50 cents / gigabyte.
- Tom
| As crt screens will probably disappear over time, I find it strange that any interlacing standards are being implemented. Why not choose a format that is easiest to compress and display? |
While 1080i doesn't really give you a full 60 frames / second it does at least hide the jerkiness reported with progressive 30 FPS cameras like the newer JVC HD-cam.
We have all managed to grow accustomed to 24 fps movies but they really do not make a very realistic picture with things move much. They are just a compromise for what we could afford to do when movies were first invented.
Mostly to make them acceptable Hollywood has to use narrow depth of field, out of focus panning backgrounds, and slower shutter speeds to create motion blur.
Of course most in Hollywood are appalled at the idea of 60 (or 72) FPS movies and claim they would be too expensive and would have too much of that video look. I guess it's just a matter of taste.
But 1080p @ 60 will probably better match the new fixed pixel displays that will become the standard. And there is already enough storage space on blue laser DVD's with modern codecs to be able encode video that way.
I don't actually expect Hollywood to rapidly embrace this idea but I think it is inevitable with the next generation of movie makers since the displays will be here and people will be able to easily compare. So as the price of "filming" to hard drive continues to drop toward zero we should begin to see some of this within another couple revolutions of the Moore's Law crank. Heck, commodity disk drive storage is already less than 50 cents / gigabyte.
- Tom
But as the source material is 24 fps, no format in the world can recover those "lost" frames. And if you simply want to predict even numbered frames, you just as easily do the same in a "100Hz" tv as we have here in norway, used to remove flickering from 25/50 interlaced pal transmisions.
I can`t see how dvd companies could do anything substantially better than that in their progresseive 24bps->interlaced 60Hz conversion...
regards
Knut Inge
I can`t see how dvd companies could do anything substantially better than that in their progresseive 24bps->interlaced 60Hz conversion...
regards
Knut Inge
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