On Tue, 02 Oct 2007 21:34:52 -0400 kony <spam@spam.com> wrote:
| On 3 Oct 2007 00:50:40 GMT,
phil-news-nospam@ipal.net wrote:
|
|>On Tue, 02 Oct 2007 19:54:39 -0400 kony <spam@spam.com> wrote:
|>| On 2 Oct 2007 12:54:39 GMT,
phil-news-nospam@ipal.net wrote:
|>|
|>|
|>|>| Of course lower is technically possible but not a practical
|>|>| design goal for a PC video card. Thus, video cards really
|>|>| don't go lower because you'd have to change the default
|>|>| behavior including the driver settings, which nobody in
|>|>| their right mind would do to output from a PC to an LCD.
|>|>
|>|>Why not? If the video card has an upper limit on pixel clock AND you
|>|>want a larger geometry, then slowing the horizontal (to get more pixels
|>|>per line) and the vertical (to get more lines per frame) is simply going
|>|>to be what you do.
|>|
|>| No you don't _want_ to do that, because there's no gain in
|>| doing it, only degradation in visual quality. This is until
|>| the data link bandwidth is exceeded, at which point a second
|>| data link is used. It is used for a reason - to preserve
|>| visual quality and/or allow for it, instead of degrading it
|>| with your proposed solution.
|>
|>There is no second data link. A card with a second data link would cost
|>more money. The geometry can be achieved with a lower frame rate with
|>the same video card, with no degradation in quality for a great many
|>uses of graphical displays, including most business uses.
|
| Again, the goal is not to use old junk then degrade
| standards to make it work, just get a normal video card like
| anyone else. Even integrated video has no problem
| outputting 60Hz at HD resolution.
You are continuing to make assumptions. I do not have any such goal
to use "old junk". I use what works with all software.
Define "a normal video card". One that costs $100?
Sure, outputting at 60Hz is possible at some resolutions. But it is not
possible on all video cards at all resolutions. Video has been a difficult
problem due to this issue for years. LCDs can now solve that problem, but
only if they accept low frame rate video.
And you continue to ignore genuine 24 fps high definition video originating
in motion picture film production, which is another source of 24 fps, or in
some cases 23.976 fps, video.
The past problems have all been expensive to solve. For example a scan
doubler would have solved the video problems in the past for CRT displays.
But a scan doubler is very expensive so it is not a practical solution.
But what is NOW practical ... and very inexpensive ... is to extend the
range of scan clock on LCD. Maybe the only reason it isn't done is because
the engineers or product managers of LCDs are as closed minded as you are
about the realities of video? or maybe they (and you?) have a vested
interest in selling high end video cards?
|>The motion picture industry does not seem to agree with you.
|
| Untrue, their choice has no bearing except a lower limit,
| not an upper limit.
This is all about the lower limit. Maybe your position on this is because
you are getting things mixed up? Or maybe it is because you think that
what I want to do is not just lower the lower limit to at least as low as
23.976 Hz/fps, but to also lower the upper limit? No. I do NOT want to
lower the upper limit at all. If anything, I think it should be raised,
at least if it is not already capable of 120 Hz.
All that is needed in an LCD to make this work is to extend the range of
the analog to digital sampling clock. Frequency synthesizer circuits,
especially those that produce pulse or square wave output, can easily go
all the way down to near zero by just putting in a larger number in the
divider register. To extend these circuits for LCD purpose, they might
need to have 1 or 2 more bits added to the register size (basically, just
use an oscillator chip that has the wider range). Then don't impose any
such limit in the software of the display.
|>Of course
|>a motion picture projector would produce flicker if run at 24 shutter
|>openings per second. The figured out ages ago that by opening the
|>shutter 48 or 72 times a second, timed so that the openings were of the
|>same timing between them, where 2 or 3 openings would have the same
|>frame, that this eliminated the flicker (even though it did not change
|>the total accumulated time the shutter was open) for most eyes.
|>
|>Were it the case that motion that changed only every 1/24 of second
|>were annoying, too, they would have change the system to a higher frame
|>rate. They did for special cases (action sports), but not for the
|>average movie.
|
| These things take time, nothing starts out as good as it
| ends up in it's final state. For example we could say if HD
| resolution mattered then they'd have just done that in the
| first place too on all distribution content.
Things that are very expnsive to do will not get done as readily. It was
well known that high definition was better as early as the 1950's when it
was first experimented with for military use. It was even deployed in the
Vietnam war. It just wasn't practical for widespread use for many reasons,
including very high prices and extreme spectral bandwidth.
So your argue is not applicable because you are referring to something that
at the time had a very high cost resistance.
| People can in fact see interruption to fluid motion at
| 24FPS. IMO, the threshold is a little closer to 35FPS but
| of course will depend on one's visual acuity and alertness.
I do not disagree with the detection of fluid motion at 24 fps. I might
argue that the upper limit is even higher than 35 fps (if that is what you
meant), but that is another topic. But what is usually displayed on office
desktop screens is not in the "fluid motion" motion category. The ability
to display higher resolution is far more important than the ability to have
fluid non-jerky motion. Sure, both would be nice. But office environments
don't justify spending the extra to get both of those features since the
motion aspect is not nearly as important.
Ever wonder why widescreen computer displays are 16:10 instead of 16:9 as
has been decided for broadcast and other video programming content? The
answer is that it is the correct aspect ratio to fit TWO pages of text in
standard 8.5x11 or A4 paper sizes, side by side. But it takes really high
resolutions like 2560x1600 to display them reasonably readable.
|>|>What the TV world refers to as frame rate is what the computer world
|>|>refers to as vertical frequency. A "1080p24" HD TV signal has a frame
|>|>rate of 24 frames per second (or 1000/1001 of that rate if locked to
|>|>legacy NTSC reference clock timing), and that is 24 Hz or 23.976 Hz.
|>|
|>| This doesn't matter, it is only a lower limit. Slowing down
|>| one end to the slowest the other would ever require is a
|>| backwards concept. On a PC (thus using LCD PC monitor),
|>| both ends can support faster than that.
|>
|>Making a video card that has a faster pixel clock rate costs more
|>money.
|
| Wrong. Today the rate is already high enough and it would
| cost more money to make an additional, special downgraded
| version that could only meet your antiquated limit. Instead
| the most cost effective is to make video cards with large
| market appeal and capable of multiple purposes.
There are still low-end and high-end video cards on the market, where
the low-end ones still have clock speed limits. Why don't you go speak
to their engineers and ask them how much it would cost them to increase
the clock frequency on them to what the high-end cards have. It would
surely not cost as much as the high-end card (because we're leaving out
the 3D texture animation features and other motion stuff not needed in
an office environment).
| Even the cheapest integrated video today has no problem
| outputting 60Hz at HD resolution. It doesn't get any
| cheaper than that.
Identify ONE such card, which has working driver software for all major
operating systems, and open specifications to validate the software or
correct it where applicable (e.g. in open source systems). The most
modern card I know of that can be universally used is the Matrox G550.
|>| Never said they did, but one could call the jerkiness of
|>| 24Hz flicker-like as well. 24 FPS is visually noticable on
|>| an LCD.
|>
|>Tell me which LCD monitor you have seen 24 fps video displayed?
|>Manufacturer and model, please.
|
| You don't seem to understand. Every single LCD monitor on
| earth, the factor is not the monitor, it is that the subject
| watching can discern breaks in movement at a rate so low as
| 24 FPS. Maybe your eyes are bad and you can't see it, but
| again it would be a matter of degrading something to meet a
| bare minimum threshold instead of keeping it at current
| quality and striving for even better.
You don't seem to understand. This is not about movement. Sure, there
are uses for monitors where movement is a factor. But there are plenty
where it is not (office uses is the big example).
I can see the 24 fps effect. It is NOT annoying to me, as I want many
movies. Hint: even if you upscan the movie to "3:2 pulldone" as is done
to show 24 fps films on NTSC or 60 fps HD video, that jerkiness in the
motion is still present.
All movies shot at 24 fps will look NO BETTER at 60 Hz than at 24 Hz on
an LCD monitor. In fact, they may even look a tad bit WORSE because of
the fact that every other frame lasts a bit longer in time than the frames
between them (at 60 Hz, one frame is displayed 3 times, then the next is
displayed 2 times, then 3, then 2, and so on). You could, of course, up
the 24 fps movie to 48 Hz or 72 Hz to eliminate that effect. But you
could just as easily leave it at 24 fps and display it on an LCD since
LCD eliminates the flicker issue just as if you had a scan converter.
|>|>Some people _need_ high frame rates for legitimate purposes, such as
|>|>gaming, and watching high action video.
|>|
|>| Most people will benefit from more than 24FPS in typical
|>| motion video uses. Most people don't have the problem you
|>| suggest and attempt to solve by lowering the rate to 24.
|>
|>They can benefit by less costly hardware, whether older or newer, by running
|>the video at 24 fps when their type of use of the computer is compatible with
|>that slow frame rate.
|
| <sigh>
|
| I can see you still don't get it. That you have some
| ancient Maxtrox card incapable of current performance levels
| from even the cheapest hardware made in the last few
| generations/years, is no support for your argument. Such an
| ancient system that video card would be found in has many
| limitations besides what the video card can output including
| processing peformance, no DVD drive, ancient OS that may not
| even be able to run the modern software for playback, and
| would not typically have a modern high resolution LCD mated
| with it for use.
|
| Randomly selecting any cheap modern system there is no
| problem doing what you suggest is problematic. Try it
| sometime.
I can see you still don't get it. It's about making things work for what
is being used ... not for what _you_ happen to use video cards for (such
as maybe watching movies shot at 60 wasteful film frames per second).
Show me ONE video card you think I should use that universally works in
all software and systems. Hint: if it has always had open programming
specifications, it will. Those that release their specs today will
qualify in about a year or two.
This is the system:
Tyan S2927A2NRF mainboard (2x Gb ether, 6 SATA-II, on board)
2x AMD Opteron (model 2222) 3.0 GHz dual-core CPU
4GB DDR-2 667 MHz ECC RAM
Matrox Millennium G550 PCIe video
2x Seagate 750GB SATA hard drives
Gentoo Linux with 2.6.22.9 kernel
But let's also talk about LOW PRICE systems that still need to be used in
an office environment. *IF* LCD monitors would do the video scanning at a
_lower_ frequency (again ... this is not eliminating the ability to scan
at a higher frequency as well, or even by default), then a low cost HIGH
RESOLUTION office desk system can be achieved at a very low cost. Because
of that one limitation in LCD monitors, that does not cost more than about
three dollars to fix (and this would only need to be done in a few models so
_you_ would never have to pay for it), we can lower the total cost of an
office computer by a couple HUNDRED dollars and have higher resolution.
But I guess you'd rather they go ahead and get a high end computer system
with more costly video and software ... just so the secretaries won't have
to be annoyed watching jerky 24 fps when they goof off in the afternoon
watching the soap operas.
--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net /
spamtrap-2007-10-04-0748@ipal.net |
|------------------------------------/-------------------------------------|
LCD scanning frequency 