I recently reviewed some software development and test specifications that required that the test of the software developed, required putting the system to the test with both normal users and developers and interested third parties users trying to "bust" the system in any way. I gave many suggestions on how to improve the process.
Does ATSC preserve the old authentic US newscaster flesh tones that drift between ghostly green and pale purple so characteristic of NTSC or are they all clamped to pale orange these days?
One DTV decoder I have sometimes loses flesh tones to grey under conditions of marginal reception in heavy rain. The rest of the picture is unaffected. After that it starts dropping blocks and adding more clicks to the audio stream (the latter being the most common failure).
More likely it is harsher quantisation used on the JPEG coefficient stream. An 8-bit RGB image is beyond most domestic LCD displays capabilities under normal room lighting. If you freeze frame then you will see the static artefacts of the image clearly, but averaged over persistence of vision they should be unobtrusive on most material.
The one thing where you can see a lot of cheap consumer MPEG playing engines fail are very dynamic sports with fast moving high contrast patterns like water skiing for instance. The white spray plume aginst dark water will break some codecs and they generate a visible mess. Take a look at a bank of sets in a showroom and you will see what I mean.
It isn't for nothing that a lot of the broadcast demos use slow pan high resolution close ups to show off the sets at their very best.
Regards, Martin Brown
** Posted from
Including chroma info I guess. Luminance certainly looks like a lot less than 8-bit rendering. They might digitize more but then it's chop chop time before it goes on the air.
Bottomline if I stay away from the TV a bit and watch without glasses it's ok. If I sit closer and have glasses on it's horrible.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
90%
Or, that 90% of websites are so horribly designed, that user's must resort to calling in for help!
-mpm
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t requires some serious image rendering horsepower.
"Dancing with the Stars" and some >>PBS and there HDTV pictures are truly = stunning. Regular DTV is a bit disappointing. Not only because of the >>sha= ky modulation scheme but also because the dynamic range seems to be very fe= w bits. Faces of people look >>like they have stockings pulled over them or= maybe they fell face-first into the masquera pot.
Does ATSC preserve the old authentic US newscaster flesh tones that drift between ghostly green and pale purple so characteristic of NTSC or are they all clamped to pale orange these days?
One DTV decoder I have sometimes loses flesh tones to grey under conditions of marginal reception in heavy rain. The rest of the picture is unaffected. After that it starts dropping blocks and adding more clicks to the audio stream (the latter being the most common failure).
More likely it is harsher quantisation used on the JPEG coefficient stream. An 8-bit RGB image is beyond most domestic LCD displays capabilities under normal room lighting. If you freeze frame then you will see the static artefacts of the image clearly, but averaged over persistence of vision they should be unobtrusive on most material.
The one thing where you can see a lot of cheap consumer MPEG playing engines fail are very dynamic sports with fast moving high contrast patterns like water skiing for instance. The white spray plume against smooth dark water will break some codecs and they generate a visible mess. Take a look at a bank of sets in a showroom and you will see what I mean.
It isn't for nothing that a lot of the broadcast demos use slow pan high resolution close ups to show off the sets at their very best.
Regards, Martin Brown
requires some serious image rendering horsepower.
"Dancing with the Stars" and some >>PBS and there HDTV pictures are truly stunning. Regular DTV is a bit disappointing. Not only because of the >>shaky modulation scheme but also because the dynamic range seems to be very few bits. Faces of people look >>like they have stockings pulled over them or maybe they fell face-first into the masquera pot.
Nope. Now they are all "tan out of a can" brown. Whether white, partly African American, Asian, now their skin all looks the same.
That's one area where ATSC works quite well. Except with earlier sets who couldn't handle the rendering volumes. With stuff like this it does not pay to be an early adopter.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
On a sunny day (Thu, 17 Jul 2008 08:10:14 -0700) it happened Joerg wrote in :
Well.... I suggest you look up mpeg2 encoding, I can assure you that even 720x576 normal DTV here at a bitrate (and that is important) of 4kbp/s can yield fantastic colors and quality. Maybe you have a DVD player, at 10Mb/s you have good DVD quality, Of course the ability to measure bitrate is in my soft, but it can be important, In the UK some stations (seen it on Sky channels) actually transmit as 352x288, so 1/4 resolution, the receiver stretches it back to normal, that means 1/4 the bitrate, so they can sell 4 channels in the same bandwidth, Without a PC DTV card and the right soft it is hard to tell what they are doing to you. But I can assure you that 8 or bits is no issue at such low bitrates.
Either your hardware is junk, or the TV stations severely limit bitrate, or both. DTV can be real good.
I don't think that necessarily follows. Plenty of times people have problems because...
1) They don't *think* to read the documentation/web pages 2) They don't *want* to read the documentation/web pages 3) The documentation/web pages are so poorly arranged that it's difficult to find the informationI've listed these in what I think is the order of frequency.
That being said, we've still come a long way where, today, pretty much anyone can sit down at a PC and create a document with various fonts, typefaces, colors, margings, graphics, etc. in on time flat compared to the old days of, e.g., DOS WordPefect 5.1.
"An empty desk is a sign of a disturbed mind." ;-)
Cheers! Rich
Correction: 4000kbp/s Here is a screen shot reording the commerial staton VOX, at 4000kbps+ ftp://panteltje.com/pub/recording_vox.png while the government owned ARD uses 7000kbps+ (almost DVD quality). ftp://panteltje.com/pub/recording_ard.png
Recording _remotely_, note the little 'kbps total' field right side halfway from the top.
So YMMV especially on commercial stations, And do not expect them to buy new film scanners or VTR, they perhaps even play from old betamax or VHS even :-)
So many things blamed on DTV may have a very different cause.
from the top.
US broadcast TV has used U-matic and 1" R-R for decades. Low power and non profit stations tried Beta & VHS a long time ago, but had to abandon it because they were impossible to maintain the proper time base correction to meet the FCC standards. If we got something on VHS we ran it through our Squeeze Zoom DVE and let it rebuild each field, but that tied up $250,000 worth of equipment.
Local access channels on CATV systems were using Bata & VHS, because they don't have to meet the same standards. It was amazing just how bad the tapes could be. Shot under bad lighting, the camera not white balanced, and the camera operator couldn't hold still.
-- http://improve-usenet.org/index.html If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm Sporadic E is the Earth\'s aluminum foil beanie for the \'global warming\' sheep.
Can you post a real screen shot, maybe with a newscaster on there? NOS Journaal or something?
from the top.
Sure. Nature movies and documentaries are broadcast in stunning 1080 line quality out here. It's regular low-res (480) and mid-res (720) where they seem to skimp on dynamic range. Some stations carry up to five digital channels in one and according to Shannon there is no free lunch.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
He's be amazed at the price of bandwidth these days, at least if you want it over the air. :-)
The original was "A clean desk is a sign of a sick mind."
I solved the problem by not having a real desk. It's officially a workbench which entitles me to make a mess without guilt:
Any semblance to a desk is purely coincidental. Notice that there's no paper anywhere in sight. It's all in cardboard boxes filed chronologically.
I've also made a study of different styles of messiness. The problem is how to efficiently convert work area into storage area. There are two fundamental types of mess. One is the vertical pile method. The object is to create the tallest pile, without having it fall over. Falling over is the signal that it's time to clean up. The other is the territorial method. It's intended to cover every square mm of desk space with clutter. No part of the desk may be visible. Overlapping is the preferred method. Once a persons desk is suitably buried in clutter, it's perfectly acceptable to continue onto other peoples benches, desks, and even the floor.
I've successfully converted the territorial style into the vertical style. I became tired of having my bench turned into someone elses temporary storage area and decided to retaliate. I invested about an hour cleaning up the lab. I carefully piled all the papers, books, magazines, dead boards, and debris on the culprits chair. The result was a very carefully balanced pile, about 2 meters high. As a side benefit, I found all my missing scope probes and clip leads. Sorry, no photos.
I also had a method to my madness. The last hour of every Friday would be devoted to cleaning up the lab. I didn't want to deal with a big mess when I came in on Monday. Everyone dropped what they were doing and cleaned up their mess. Borrowed and stolen equipment were also returned. Leaving early was punishable by having all the unclassified junk dumped on their workbench or desk. Visiting managers were handed a broom or told to file books and reports. It worked well.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
mode
parameters
deadly
malfunction
Even though I was da boss I had a reputation of busting almost any software driven process so they used me as a buster. If I couldn't bust it anymore the machine was considered to be almost mil-spec :-)
Busting includes pulling the power plug and plugging it in shortly thereafter. On poorly designed system that always seems to be able to fry things up pretty good.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
On a sunny day (Thu, 17 Jul 2008 10:51:08 -0700) it happened Joerg wrote in :
Shure, but I am reording a move right now, later tonight, in the mean time: you did see the HD shot from BBC HD IIRC: BBC HD demo screenshot (1920x1080 interlaced, without de-interlace): ftp://panteltje.com/pub/bbc_hd.gif
720x576 testcard: ftp://panteltje.com/pub/testcard.png
Actually 720x576 is this one, the other one was scaled down....: ftp://panteltje.com/pub/testcard-2.png
hat
00kbps+fway from the top.
s. Low power
& VHS, becauseMike -
Not sure if you're aware of it, but there a HUGE market for Umatic to HD conversion. There's so much footage on UMatic, and so few players (and no parts, current production, etc...) that it is literally a race against time to convert all this material. Even under perfect storage conditions, UMatic tapes will deterioate.
To my knowledge ONLY ONE company has built a machine to automatically dupe these tapes. Their name escapes me at the moment (met them in New York last year), but I know they have the contract to conver the Library of Congress' archive. Seems like the perfect niche market...?
-Michael
Nice. It does have more vertical frazzles than 1080 here. But I am not sure how much of that is due to my displaying it on a CRT here. Although it's a hi-res Trinitron.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
from the top.
Southern Comfort helps with the holding still :-)
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
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