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post #31 of 44 Old 11-19-2006, 01:46 AM
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Quote:
Originally Posted by pcCinema View Post

Lastly (not trying to make you feel bad) I honestly don't think your display has the electronic bandwidth , optical capability, or beam spot capability to show as much detail as any 8" or 9" standard high res crt projector. You should compare your set to a nec XG, g70, g90, ampro 3600, 4600, barco 1208, 1209, cine9, etc etc. Your set is based on a compromise of getting more brightness out of crt technology and unfortunately was not about getting the highest bandwidth or resolution. What ansi resolution is it rated as being able to fully resolve?

ILAs had some pretty impressive CRT sections in them, they weren't cheap projectors. Resolution certainly wasn't a problem for them, they could do 2330x1750 when driven hard.
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post #32 of 44 Old 11-19-2006, 04:23 AM
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Hey gremmy in addition to the Sony G90 there are lots of CRT computer monitors that accept 1080p without a problem. As WM said they display what you send them as long as they can sync up with the signal.
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post #33 of 44 Old 11-19-2006, 10:45 AM - Thread Starter
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I would like to thank those you have contributed to this post. It has indeed helped me get a better understanding.

The one part that is still a tuff cookie to grab is the fact that even if you go from 1080i to 1080p the acutal resoution of the picture dose not increase, yet the scan rate doiubles.

Dose doubling the scan rate acutally double the resoution?

Its proabaly a arguement of terminology.

No, it dose not double the "Resoution", yet its still twice the amount of data in the same amount of time.

The real world question is---dose it make the picture look twice as good?

In terms of my projector based on Analog CRT shooting their light into an Analog LCD crytsal (no pixels) (effectly just acting light a big-*ss light amplifier, the difference beween feeding it 1080i and feeding it externally scaled 1080i---to--->1080p is indeed a noticable PQ inprovement.

Can my machine acutally turely render a ture 1080p 60 input at full res. I'd have to say the answer is a strong yes. Im tyring to find a way to prove it other then me saying it just look better.

These numers I pulled from the terminal screen on the PC when hooked up to the RS232 port on the projector. (last number comes from the VP50's info screen).

1080i

Horz Rate: 34.45
Frame Rate: 30.50
Horz Count: 1146
Interlace : Yes
Pixel Rate : 74.176 Mhz

1080p

Horz Rate : 68.74
Frame Rate : 61.10
Horz Count : 1125
Interlace : No
Pixel Rate : 148.325 Mhz

My input selected on the vp50 at the time was SD-SDI from the Dennon DVD player--but I dont think it would matter what input on the scaler I had selected--but I didnt try anyting else.

Carey
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post #34 of 44 Old 11-19-2006, 10:49 AM
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Quote:
Originally Posted by imws View Post

Hey gremmy in addition to the Sony G90 there are lots of CRT computer monitors that accept 1080p without a problem. As WM said they display what you send them as long as they can sync up with the signal.

Thanks for the clarification. As I mentioned earlier, I had previously thought that CRTs were an inherently interlaced technology, and I have learned something new in this thread.


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post #35 of 44 Old 11-23-2006, 11:04 PM
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Originally Posted by wm View Post

Assuming a true 1080p source, not an upscaled one, and identical scan rates, the amount of actual data is DOUBLE with 1080p. 1080i data rate is roughly 33.5 khz. 1080P data rate is roughly 67 khz.

True 1080p sources are rare though...

I assume you mean Mhz rather than khz. The data rate is also heavily affected by the quality of the codec, with the newer codecs like VC-1 and mpeg4 being the most efficient and usually less than 20Mbs (for 24fps sources). The data rates for uncompressed HD on the otherhand are startling. 10-bit 1080i60 for example is a whopping 932Mbs. Here are some numbers from Microsoft:

Table 2. Storage requirements for compressed and uncompressed data

Format, Data rate (Mbps), GB per hour of video
720 x 480 DV 4:1:1, 25, 11
720 x 480 DV50 4:2:2, 50, 22
HD-DVCPRO, 100, 44
Uncompressed 10-bit formats
720 x 486 4:2:0, 210, 92
1280 x 720/24p 4:2:0, 332, 146
1280 x 720/60p 4:2:0, 818, 364
1920 x 1080/24p 4:2:0, 746, 328
1920 x 1080/60i 4:2:0, 932, 410


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post #36 of 44 Old 11-23-2006, 11:39 PM
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Quote:
Originally Posted by Mark Petersen View Post

I assume you mean Mhz rather than khz. The data rate is also heavily affected by the quality of the codec, with the newer codecs like VC-1 and mpeg4 being the most efficient and usually less than 20Mbs (for 24fps sources). The data rates for uncompressed HD on the otherhand are startling. 10-bit 1080i60 for example is a whopping 932Mbs. Here are some numbers from Microsoft:

Table 2. Storage requirements for compressed and uncompressed data

Format, Data rate (Mbps), GB per hour of video
720 x 480 DV 4:1:1, 25, 11
720 x 480 DV50 4:2:2, 50, 22
HD-DVCPRO, 100, 44
Uncompressed 10-bit formats
720 x 486 4:2:0, 210, 92
1280 x 720/24p 4:2:0, 332, 146
1280 x 720/60p 4:2:0, 818, 364
1920 x 1080/24p 4:2:0, 746, 328
1920 x 1080/60i 4:2:0, 932, 410

The video has to be uncompressed before it can be fed into the data pipeline from your source to your display, so compressed data rates are a moot point. Once the data has been expanded out to 8/10/12 bit 4:2:0/4:2:2/4:4:4 YCbCr/RGB, it's all the same size as comparable data.
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post #37 of 44 Old 11-24-2006, 12:59 PM
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Quote:
Originally Posted by Carled View Post

so compressed data rates are a moot point.

Unless of course you're a cable/sat provider or a BD/HD-DVD production company and then it becomes the most important point


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post #38 of 44 Old 11-24-2006, 02:46 PM
 
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Quote:
Originally Posted by ctreesh View Post

I would like to thank those you have contributed to this post. It has indeed helped me get a better understanding.

The one part that is still a tuff cookie to grab is the fact that even if you go from 1080i to 1080p the acutal resoution of the picture dose not increase, yet the scan rate doiubles.

Dose doubling the scan rate acutally double the resoution?

Its proabaly a arguement of terminology.

No, it dose not double the "Resoution", yet its still twice the amount of data in the same amount of time.

The real world question is---dose it make the picture look twice as good?

In terms of my projector based on Analog CRT shooting their light into an Analog LCD crytsal (no pixels) (effectly just acting light a big-*ss light amplifier, the difference beween feeding it 1080i and feeding it externally scaled 1080i---to--->1080p is indeed a noticable PQ inprovement.

Can my machine acutally turely render a ture 1080p 60 input at full res. I'd have to say the answer is a strong yes. Im tyring to find a way to prove it other then me saying it just look better.

These numers I pulled from the terminal screen on the PC when hooked up to the RS232 port on the projector. (last number comes from the VP50's info screen).

1080i

Horz Rate: 34.45
Frame Rate: 30.50
Horz Count: 1146
Interlace : Yes
Pixel Rate : 74.176 Mhz

1080p

Horz Rate : 68.74
Frame Rate : 61.10
Horz Count : 1125
Interlace : No
Pixel Rate : 148.325 Mhz

My input selected on the vp50 at the time was SD-SDI from the Dennon DVD player--but I dont think it would matter what input on the scaler I had selected--but I didnt try anyting else.

Carey

This is a confusing matter because lots of 1080i content may actually be sourced from 24p film rate content so it may be reassembled that way. If you have a given scanrate with a source that matches it, for instance pretend you have a 1080i60 source and another source that is 1080p60, yes the latter will have twice as much resolution because each of the 60 fields will be full 1080p while the former would be only half that for each field. The scanrate is also twice as much because the latter is scanning a full 1920x1080 field each 1/60th of a second. The former is only scanning 1920x540 field each 1/60th of a second.

However, what happens is that usually you'll have an interlaced source that is video at a video rate of say 1080i60, and if you have a 1080p source usually that's going to be 1080p24 for film stuff or maybe 1080p30 for progressive video. So the pixel rate for 1080p24 is actually a little bit less than something like 1080i60. 1080p24 would be the same as 1080i48 except in source structure because the progressive content would be capturing complete frames, while the interlaced source content would be capturing half frames (fields) spaced in time so there you have temporal/interlacing artifacts that may be problematic.

So if you hold everything else the same and go from interlaced to progressive you do have twice the resolution, however that's usually not the case because the framerates aren't going to end up that much different.
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post #39 of 44 Old 02-22-2007, 06:24 PM - Thread Starter
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Thanks again for all the input and feedback. Its a very complex topic indeed.

What I have learned is this...

In 1080i---only 540 lines of video are on a CRT display at any one time.
In 1080p-- All 1080 lines of video are on the CRT display at the same time.

On fixed pixel displays, all 1080 lines are on the screen at the same time, but there is a differense betteen 1080i and 1080p sources. 1080p will have more 'content'.
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post #40 of 44 Old 02-22-2007, 07:06 PM
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Quote:
Originally Posted by ctreesh View Post

What I have learned is this...

In 1080i---only 540 lines of video are on a CRT display at any one time.
In 1080p-- All 1080 lines of video are on the CRT display at the same time.

On fixed pixel displays, all 1080 lines are on the screen at the same time, but there is a differense betteen 1080i and 1080p sources. 1080p will have more 'content'.

You should add to that:

The transmission mode (i.e., 1080i/1080p) does not necessarily determine the amount of data or resolution in the actual picture data, nor does it explicitly define the final display format.

For example, a 1080p/24 source (like an HD DVD movie) can be fully encoded into 1080p/24, 1080i/60, or 1080p/60 (as over an HDMI cable). In each case, the amount of actual source data being transmitted is identical - 100% of the original data is there (assuming the conversion is done correctly). Also, in each case, the final display resolution and format can be 1080p/24, 1080i/60, 1080p/60, 7200/60, 480i/60, etc., depending on what the display does with the signal it receives.

That said, if you encode a 1080p/60 source (if you can find one) into 1080i/60 for transmission, you can't get the remaining lines back - you're now stuck at 1080i/60, 1080p/30, or another resolution/frame rate combo equal to or slower than 1080i/60.

Make sense?
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post #41 of 44 Old 02-22-2007, 08:08 PM
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Quote:
Originally Posted by ctreesh View Post

I would like to thank those you have contributed to this post. It has indeed helped me get a better understanding.

The one part that is still a tuff cookie to grab is the fact that even if you go from 1080i to 1080p the acutal resoution of the picture dose not increase, yet the scan rate doiubles.

Dose doubling the scan rate acutally double the resoution?

No, however as is made apparent by DVD, it can obscure less/reveal more of the detail that is present in the source.

Most interlaced displays overlap scan lines slightly, to reduce the artifacts caused by scanning at a low rate. As such they tend to blur the fields together, obscuring detail present in the image.

By "progressive scanning", especially on progressive sources (ie film sourced content) you can bypass this blurring and get a result that's a significant improvement.

As for why there are progressive scan DVD players when displays have deinterlacers, it's primarilly because it's much easier to do the inverse telecine (IVTC) in the digital domain, where you have all the information (ie pulldown flags), vs after analog conversion where all you have is fields, and you have to evaluate ("guess") what fields go together.

Also, just so it's not missed, probably 90% of DVDs (ie those from Hollywood) are actually 480p. They contain true progressive content that is stored as fields and have metadata (flags) included for NTSC output. Note that stored as fields is different than being interlaced.

Quote:


Its proabaly a arguement of terminology.

No, it dose not double the "Resoution", yet its still twice the amount of data in the same amount of time.

Not necessarilly, as in the case of film content, interlaced or progressive transmission are just two different ways of carrying the same data.

Quote:


The real world question is---dose it make the picture look twice as good?

That's a value judgement and I think I disagree with many here on the magnitude of differences

Quote:


Thanks again for all the input and feedback. Its a very complex topic indeed.

It's complex, but I think you're making it harder than it needs to be.

For example, as Mauney noted, there are really three distinct issues:

Source format
Transmission format
Display format

Nothing connects one to another, and you can come up with a huge number of combinations between them.

Quote:


What I have learned is this...

In 1080i---only 540 lines of video are on a CRT display at any one time.
In 1080p-- All 1080 lines of video are on the CRT display at the same time.

True, but I'm not sure what bearing it has on anything.

Quote:


On fixed pixel displays, all 1080 lines are on the screen at the same time, but there is a differense betteen 1080i and 1080p sources. 1080p will have more 'content'.

Not necessarilly. Actually, in all reality, 1080i sources probably have more real data since 1080p60 sources are basically unheard of (it's not part of ATSC AFAIK). Basically the industry has standardized on 1080i60 and 1080p24 for source formats, the former being for video (documentaries, liveTV, DiscoveryHD type stuff), and the later being for movies and many TV shows. The former actually has the higher data rate.

As far as transmission goes, the industry so far has standardized on just 1080i60, but 1080p60 is a close second, with 1080p24 gaining traction slowly.

Like I said, I really think you're making this too hard.

1080p is the pinnacle of display technology at the moment (especially with things like the RS1 coming out).

Essentially all movies, and a large portion of TV content is 1080p24 (even if it's encapsulated in 1080i60), and a 1080p display is the only way to optimally display these.

For the remaining 1080 content, ie 1080i60, video processing is to a point now (RealtaHQV, Gennum VXP) that a 1080p display is probably the best way to view HD video as well.

For everything else, 1080p displays mean upconverting, ie they can display any other format without loss.

And the big thing, 1080i displays (especially FPs) are a dying breed these days, and the latest crop of digitals is rapidly closing (if not closed) the gap on CRT in image quality.

See what an anamorphoscopic lens can do,
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post #42 of 44 Old 02-23-2007, 07:27 AM
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Quote:
Originally Posted by ctreesh View Post

The one part that is still a tuff cookie to grab is the fact that even if you go from 1080i to 1080p the acutal resoution of the picture dose not increase, yet the scan rate doiubles. Dose doubling the scan rate acutally double the resoution?

Might help to distinguish between 1080p deinterlaced from 1080i sources for progressive display and 1080p-sourced signals. 1080/60i video cameras used for live or some recorded programs capture 1920X1080 images (visible area) as two 1/60-sec, interlaced, 540-line TV fields. That requires a 1.5 Gbps (giga or billion bits/second) signal, typically compressed way down to about 19 Mbps (mega or million bits/second) or less for delivery into homes.

Compare that with TV cameras, like Sony's pro 1500 series, that capture images at 1080/60p. Since that's a complete 1920X1080 frame in 1/60 sec (not interlaced), this requires a 3-Gbps signal, double that of standard HDTV. 1080/60p isn't a standard transmissible HD signal because of its 3-Gbps bandwidth, although 1080/60p cameras/recorders are being used; (another story).

Comparing the interlaced vs. progressive camera capture, they're both 1920X1080 images with about the same resolution. But the all-at-once 1080/60p frame capture eliminates the image artifacts of interlaced capture. And 1080/60p home delivery, still not practical, means that required vertical filtering--smearing interlaced signals vertically to minimize 'twittering' of fine details--could be eliminated, thus boosting effective vertical resolution.

Films or tapes captured at 24p, delivered at the required (OTA) 1920X1080/60i broadcast standard, become interlaced by adding extra duplicated TV fields (2-3 pulldown). The original progressive 24p images can be recaptured with reverse 2-3 pulldown, but the resolvable detail ( effective resolution ) is considerably less than the full 1920X1080 format resolution--for either movies or video (interlaced or progressive) from TV cameras. -- John
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post #43 of 44 Old 02-23-2007, 02:28 PM
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Finally, someone who spells worse than me.
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post #44 of 44 Old 01-05-2012, 06:19 PM - Thread Starter
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Wow....I have not visited this post in a long time. I kinda forgot about it.

Good replies tho and I did learn a few things.

I have progressed a bit since I made this post. While this is probably considered an older player, I use an LG Super Blue(HD-DVD&BluRay), that outputs 1080p/24. This is fed into an outboard DVDO VP50 scaler. That outputs 1080p/60 also via HDMI.

I use a splitter, one side feeds my Samsung LED DLP tv set, the other side feeds into a DVI-dongle-to-a-HD-Fury (original pixel-for-pixel conversion to RGBHV)---that feeds my Analog CRT unit a true 1080p/60 analog signal.


I never considered that a CRT direct view is truly a "fixed pixel device"---but now that you have said that....your right, it pretty much is.

Also, found that post about 1080i = 540p to be very enlightening. Don't see a lot of displays as advertised as 2160i compatible---but thats really what we are seeing aint it?

Is 1080i vs 1080p on a matrix display the same?

Well, now it makes much better sense to say no, becuase clearly 2160i is twice as good as 1080i.

In real-word expirence...here is something that can clearly be seen as "twice the res". On the menu of my DVD0 VP50 scaler, 1080i looks twice as large then it dose on 1080p. Drop down menus from the remote eat up most of the screen in 1080i, but only about 1/2 the screen area in 1080p.

My TV set is DLP and yes, I can see the difference between 1080i and 1080p clearly with this on screen menu alone.

As for the actual specs of what my CRT beast will resolve...I dont know for sure. Your probably right tho....its CRT tubes are only 7inch, and the scan lines are "squished" into a 16x9 aspect ratio. (analog squished).

The "judder" test pattern is competely smooth on the CRT system, and not-so-good on the DLP. (I wish there was a way to "shut down" the internal scaler in the TV set).

My apologies for posting un-checked facts. I'm a little less arrogant now then when I first joined.
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